CN101295785B

CN101295785B - Anode active material and secondary battery

Info

Publication number: CN101295785B
Application number: CN2008100954550A
Authority: CN
Inventors: 石原英贵
Original assignee: Sony Corp
Current assignee: Murata Northeast China; Murata Manufacturing Co Ltd
Priority date: 2007-04-23
Filing date: 2008-04-23
Publication date: 2011-06-22
Anticipated expiration: 2028-04-23
Also published as: JP2008293955A; CN101295785A; JP4897718B2

Abstract

A secondary battery having a high capacity and superior cycle characteristics and an anode active material used for it are provided. The anode active material contains, as an element, at least tin (Sn), iron (Fe), cobalt (Co), and carbon (C). A carbon content is in the range from 11.9 wt % to 29.7 wt %, a total ratio of iron and cobalt to a total of tin, iron, and cobalt is in the range from 26.4 wt % to 48.5 wt %, and a cobalt ratio to a total of iron and cobalt is in the range from 9.9 wt % to 79.5 wt %. A reactive phase capable of reacting with an electrode reactant is included. A half-width of a diffraction peak obtained by X-ray diffraction (peak observed at diffraction angle 2theta of between 41 degrees and 45 degrees) is 1.0 degree or more.

Description

Negative electrode active material and secondary cell

The cross reference of related application

The present invention comprises the spy who is filed in Japan Patent office with on April 23rd, 2007 and is willing to that the spy who 2007-113015 and on February 14th, 2008 is filed in Japan Patent office is willing to the theme that 2008-033343 is relevant, is incorporated herein its full content as a reference.

Technical field

The secondary cell that the present invention relates to comprise the negative electrode active material of tin, iron, cobalt and carbon and use this negative electrode active material.

Background technology

In recent years, introduced multiple portable electric appts, for example integral photographic machine (video tape recorder), mobile phone and subnotebook PC, and reduced their size and weight.Owing to the key device battery, particularly secondary cell of the compact power that is used as these electronic equipments are very important, so actively promoted the research and development that improve energy density.Particularly, compare with nickel-cadmium cell with existing aqueous electrolyte secondary cell excide battery, rechargeable nonaqueous electrolytic battery (for example lithium rechargeable battery) can provide high energy density.Therefore, carried out the research that improves this rechargeable nonaqueous electrolytic battery in different fields.

In lithium rechargeable battery,, the material with carbon element that capacity is higher and cycle characteristics is good, for example difficult graphitized carbon and graphite have been extensive use of as negative electrode active material.Yet, because in recent years to the demand of high power capacity more, so must further improve the capacity of material with carbon element.

Under this background, developed under the situation of using material with carbon element by selecting carbonized stock and formation condition to realize the technology (for example opening flat 8-315825 communique) of high power capacity with reference to the spy.Yet under the situation of using this material with carbon element, the negative discharge electromotive force is 0.8V～1.0V with respect to lithium, and battery discharge voltage reduces when the structure secondary cell.Therefore, in this case, can not expect that energy content of battery density obviously improves.In addition, in this case, have following shortcoming: it is big to lag behind in charging and discharging curve is linear, and energy efficiency is low in each charge and discharge cycles.

In addition, be higher than cathode of carbon material, promoted research alloy material as capacity.In this alloy material, the electrochemistry alloying of certain types of metals and lithium and reversible this fact that the gained alloy generates and decomposes have been utilized.For example, developed the high power capacity negative pole that uses Li-Al alloy or Sn alloy.In addition, developed the high power capacity negative pole that the Si alloy is made (for example with reference to U.S. Patent No. 4950566).

Yet, discharge and recharge and cause Li-Al alloy, Sn alloy or Si alloy to expand and shrink, all make the negative pole efflorescence whenever repeating to discharge and recharge, thereby the cycle characteristics extreme difference.

Therefore, as the technology of improving cycle characteristics, to studying as the alloying component repression of swelling with tin or silicon.For example, proposed that for example iron and cobalt and tin (are for example opened 2004-022306,2004-063400,2005-078999,2006-107792,2006-128051 and 2006-344403 communique with reference to the spy as alloying component with transition metal; " Journal of the Electrochemical Society; " 1999, No.146, p.405, " Journal of the Electrochemical Society; " 1999, No.146, p.414, with " Journal of the Electrochemical Society; " 1999, No.146, p.423).In addition, Mg has been proposed ₂Si etc. (for example with reference to " Journal of the Electrochemical Society, " 1999, No.146, p.4401).In addition, (A represents at least a in the transition metal to have proposed SnAX for example, X represents to be selected from least a of carbon etc.), wherein the ratio of Sn/ (Sn+A+X) is 20 atom %～80 atom % (for example opening the 2000-311681 communique with reference to the spy), and with the material with carbon element alloyed metal (AM) compound (A that can insert and deviate from lithium _1-xB _x: A is tin, silicon etc., and B is iron, cobalt etc.) be dispersed in the material (for example opening the 2004-349253 communique) in the material with carbon element with reference to the spy.

Summary of the invention

Yet even adopt aforementioned techniques, under present situation, the effect of improving cycle characteristics is still insufficient, and does not make full use of the advantage of the high power capacity negative pole that adopts alloy material.Therefore, explored the further technology of improving cycle characteristics.

Thereby in the present invention, expectation provides secondary cell with high power capacity and good circulation characteristic and the negative electrode active material that is used for this secondary cell.

According to embodiment of the present invention, provide the negative electrode active material that comprises tin, iron, cobalt and carbon at least.Carbon content is 11.9wt%～29.7wt%, and the ratio of iron, cobalt summation and tin, iron, cobalt summation is that the ratio of 26.4wt%～48.5wt% and cobalt and iron, cobalt summation is 9.9wt%～79.5wt%.Negative electrode active material have can with the reacting phase of electrode reaction thing reaction.The half-breadth of the diffraction maximum that obtains by X-ray diffraction (at the observed peak, the angle of diffraction 2 θ places between 41 degree and 45 degree) be 1.0 degree or more than.

According to embodiment of the present invention, provide to comprise positive pole, negative pole and electrolytical secondary cell.Described negative pole comprises the negative electrode active material that contains tin, iron, cobalt and carbon at least.Carbon content in this negative electrode active material is 11.9wt%～29.7wt%.The ratio of iron, cobalt summation and tin, iron, cobalt summation is 26.4wt%～48.5wt%.The ratio of cobalt and iron, cobalt summation is 9.9wt%～79.5wt%.This negative electrode active material have can with the reacting phase of electrode reaction thing reaction.The half-breadth of the diffraction maximum that obtains by X-ray diffraction (at the observed peak, the angle of diffraction 2 θ places between 41 degree and 45 degree) be 1.0 degree or more than.

According to embodiments of the present invention negative electrode active material have can and the half-breadth of the reacting phase of electrode reaction thing reaction and the diffraction maximum (at the observed peak, the angle of diffraction 2 θ places between 41 degree and 45 degree) that obtains by X-ray diffraction be 1.0 degree or more than.In this case, because negative electrode active material comprises tin element, so can obtain high power capacity.In addition, negative electrode active material comprises iron and cobalt element, and the ratio of iron, cobalt summation and tin, iron, cobalt summation is 26.4wt%～48.5wt%, and the ratio of cobalt and iron, cobalt summation is 9.9wt%～79.5wt%.Thereby, when keeping high power capacity, improved cycle characteristics.In addition, because negative electrode active material comprises carbon, and carbon content is 11.9wt%～29.7wt%, so further improved cycle characteristics.Therefore, the secondary cell according to the embodiment of the present invention of using this negative active core-shell material can obtain high power capacity and can obtain good cycle characteristics.

In addition, if comprising, negative electrode active material is selected from least a in aluminium, titanium, vanadium, chromium, niobium and the tantalum; If perhaps negative electrode active material comprises and is selected from least a in nickel, copper, zinc, gallium and the indium; If perhaps negative electrode active material comprises the element in above-mentioned two group elements simultaneously, then can further improve cycle characteristics.Particularly, when negative electrode active material comprised element in above-mentioned two group elements simultaneously, if the content of last group element is 0.1wt%～9.9wt%, the content of back one group element was 0.5wt%～14.9wt%, then can obtain effect preferably.

In addition, if negative electrode active material comprises silver element, then can further improve cycle characteristics.Particularly, if silver content is 0.1wt%～9.9wt%, then can obtain effect preferably.

In addition, if comprising, negative electrode active material is selected from least a in aluminium, titanium, vanadium, chromium, niobium and the tantalum; Be selected from least a in nickel, copper, zinc, gallium and the indium; And silver, then can further improve cycle characteristics.

According to following explanation, of the present invention other will manifest more fully with further purpose, feature and advantage.

Description of drawings

Fig. 1 is the sectional view of the structure of first kind of secondary cell of demonstration embodiment of the present invention;

Fig. 2 is for showing the local sectional view that amplifies of spiral winding electrode shown in Figure 1;

Fig. 3 is the decomposition diagram of the structure of second kind of secondary cell of demonstration embodiment of the present invention;

Fig. 4 is the sectional view of the structure of the spiral winding electrode shown in Figure 3 of demonstration IV-IV intercepting along the line;

Fig. 5 is the sectional view of the structure of the third secondary cell of demonstration embodiment of the present invention;

Fig. 6 shows the example by the peak of the x-ray photoelectron power spectrum acquisition of the negative electrode active material that forms among the embodiment;

Fig. 7 is for showing the sectional view of the structure of the Coin shape secondary cell of formation in an embodiment;

The characteristic pattern of Fig. 8 for concerning between the carbon content in the demonstration negative electrode active material and the capability retention/initial charge capacity;

The example at the peak that Fig. 9 obtains for the x-ray photoelectron power spectrum that shows by the negative electrode active material that forms in comparative example;

The characteristic pattern of Figure 10 for concerning between the ratio that shows iron, cobalt summation and tin, iron, cobalt summation in the negative electrode active material and the capability retention/initial charge capacity;

The characteristic pattern of Figure 11 for concerning between the ratio that shows cobalt and iron in the negative electrode active material, cobalt summation and the capability retention/initial charge capacity;

The characteristic pattern of Figure 12 for concerning between Ti content and the capability retention/initial charge capacity in the demonstration negative electrode active material;

The characteristic pattern of Figure 13 for concerning between copper content and the capability retention/initial charge capacity in the demonstration negative electrode active material;

The characteristic pattern of Figure 14 for concerning between silver content and the capability retention/initial charge capacity in the demonstration negative electrode active material;

Figure 15 shows the characteristic pattern that concerns by between the half-breadth of the diffraction maximum of X-ray diffraction acquisition and the capability retention/initial charge capacity.

Embodiment

After this will describe in detail embodiment of the present invention with reference to the accompanying drawings.

According to embodiments of the present invention negative electrode active material can with for example lithium reaction and comprise tin, iron and cobalt element (first to element) of electrode reaction thing.The tin of Unit Weight has high lithium reacting dose, thereby can obtain high power capacity.Use simple substance tin to be difficult to obtain sufficient cycle characteristics.Yet if negative electrode active material comprises iron and cobalt, cycle characteristics improves.

For iron content and cobalt content, the ratio of iron, cobalt summation and tin, iron, cobalt summation is preferably 26.4wt%～48.5wt%, more preferably 29.2wt%～48.5wt%.If this summation ratio is low, then iron content and cobalt content are low, thereby are difficult to obtain sufficient cycle characteristics.Simultaneously, if this summation ratio height, then tin content is low, thereby is difficult to obtain to be higher than for example capacity of material with carbon element of existing negative material.

In addition, for cobalt content, the ratio of cobalt and iron, cobalt summation is preferably 9.9wt%～79.5wt%, more preferably 29.5wt%～79.5wt%.If this ratio is low, then cobalt content is low, thereby is difficult to obtain sufficient cycle characteristics.Simultaneously, if this ratio height, then tin content is low, thereby is difficult to obtain to be higher than for example capacity of material with carbon element of existing negative material.

Negative electrode active material also comprises carbon (quaternary element) beyond detin, iron and the cobalt.Thereby, can further improve cycle characteristics.

Carbon content is preferably 11.9wt%～29.7wt%, and more preferably 14.9wt%～29.7wt% very preferably is 17.8wt%～29.7wt%.In described scope, can obtain good effect.

Particularly, negative electrode active material preferably also comprises at least a (The Fifth Element) that is selected from aluminium, titanium, vanadium, chromium, niobium and the tantalum element beyond detin, iron, cobalt and the carbon.Thereby, can further improve cycle characteristics.

In addition, negative electrode active material preferably also comprises at least a (the hexa-atomic element) that is selected from nickel, copper, zinc, gallium and the phosphide element.Thereby, can further improve cycle characteristics.

Negative electrode active material can only comprise The Fifth Element, can only comprise hexa-atomic element or comprise both simultaneously except that first to fourth element.In this case, if negative electrode active material comprises The Fifth Element and hexa-atomic element, then can obtain effect preferably.Particularly, if negative electrode active material comprises The Fifth Element and hexa-atomic element, then the content of The Fifth Element is preferably 0.1wt%～9.9wt%, and the content of hexa-atomic element is preferably 0.5wt%～14.9wt%.Thereby, can obtain effect preferably.

In addition, negative electrode active material preferably also comprises silver element (the 7th element) beyond detin, iron, cobalt and the carbon.Thereby, can further improve cycle characteristics.

Silver content is preferably 0.1wt%～9.9wt%, more preferably 0.9wt%～9.9wt%.In described scope, can obtain effect preferably.

Except that first to fourth element, negative electrode active material can only comprise the 5th and hexa-atomic element, can only comprise the 7th element or can comprise described three.In this case, if negative electrode active material comprises described three, then can obtain effect preferably.

Negative electrode active material has low crystalline phase or amorphous phase.This be mutually can with the reacting phase of reaction such as lithium, thereby obtain good cycle characteristics.Reacting phase comprises for example above-mentioned element and mainly makes it the low or amorphous of degree of crystallinity by carbon.The diffraction maximum of this phase that obtains by X-ray diffraction has the angle of diffraction 2 θ between 20 degree and 50 degree, and wherein the CuK alpha ray is as specific X ray, sweep speed be 1 degree/minute.By relatively carrying out X-ray diffraction spectrum before and after the electrochemical reaction, be easy to determine that the diffraction maximum that obtains by X-ray diffraction is whether corresponding to the reacting phase that can react with lithium etc. with lithium etc.For example, if different with the position of diffraction maximum before and after lithium etc. carries out electrochemical reaction, then the diffraction maximum that obtains by X-ray diffraction corresponding to can with the reacting phase of reaction such as lithium.

The half-breadth of the negative electrode active material diffraction maximum (at the observed peak, the angle of diffraction 2 θ places between 41 degree and 45 degree) that obtains by X-ray diffraction be 1.0 degree or more than, wherein the CuK alpha ray is as specific X ray, sweep speed be 1 degree/minute.Thereby lithium etc. insert more reposefully and deviate from, and less with electrolytical reactivity.

As give a definition and adopt the diffraction maximum half-breadth of aforementioned range (1.0 degree or more than).As mentioned above, the wide diffraction maximum of reacting phase is in 2 θ=20～50 degree scopes.In this diffraction maximum, obviously there are two peaks near 30 degree and near 43 degree.At this moment, adopting the diffraction maximum of aforementioned range (1.0 degree or more than) is near 43 degree (41～45 degree) peaks.Be the half-breadth at acquisition peak, utilization is spent the baselines of observed broad peak as carrying on the back at the end (basis) at 20 degree～50,41～45 peaks of spending are carried out match, and calculating the peak then is by force the peak width at the height place of half value.After electrode reaction, exist in the peak between 41 degree and 45 degree, and its peak is constant after electrode reaction by force.Thereby, according to the above-mentioned half-breadth of X-ray diffraction double counting as a result, and stably check described half-breadth whether to drop in the above-mentioned scope (1.0 degree or more than).

In some cases, except that aforementioned low crystalline phase or aforementioned amorphous phase, negative electrode active material also has the phase that comprises each element or its a part of simple substance.

In addition, in negative electrode active material, to the small part carbon preferably with metallic element or metalloid element bonding as other element.The interior poly-or crystallization of tin etc. can cause cycle characteristics to reduce.Thus, if carbon and other element bonding have then been avoided this interior poly-or crystallization.

As the method for measurement of check element bonding state, for example enumerate x-ray photoelectron power spectrum (XPS).In XPS, utilize grenz ray (in commercially available equipment, adopting Al-K alpha ray or Mg-K alpha ray) irradiation sample, measure the photoelectronic kinetic energy of overflowing, thereby the element that checking is counted apart from sample surfaces in the zone of nm is formed and bonding state from sample surfaces.

The binding energy of element inner tracks electronics mainly is to change with the charge density of element approx.For example, the element that exists around carbon and its interacts and makes under the situation that its charge density reduces, and outer shell electronics for example 2p electronics reduces, thereby the 1s electronics of carbon is fettered consumingly by this shell.If promptly the electric charge of element reduces, then binding energy increases.In XPS, if binding energy increases, then the peak is offset to the higher zone of energy.

In XPS, for graphite, make gold atom 4f track (Au 4f) peak in the equipment that the 84.0eV place obtains having carried out energy calibration, observe 1s track (C1s) peak of carbon at the 284.5eV place.For surface contamination carbon, observe the peak at the 284.8eV place.In addition, for the higher carbon of charge density, if for example carbon and the element bonding littler than its electronegativity, then at the regional observation that is lower than 284.5eV to C 1s peak.Promptly at least a portion of contained carbon is observed the compound crest of C1s that negative electrode active material obtains with as bondings such as the metallic element of other element, metalloid elements the time in being lower than the zone of 284.5eV in negative electrode active material.

In the XPS measuring of negative electrode active material, if surface coverage has surface contamination carbon, the argon-ion gun that then preferred utilization is attached on the XPS equipment carries out sputter slightly to the surface.In addition, when the negative electrode active material of measuring is present in the negative pole of following secondary cell, preferably after taking secondary cell apart and taking out negative pole, with volatile solvent for example dimethyl carbonate wash this negative pole.Thereby remove the low voc solvent and the electrolytic salt that exist on the negative terminal surface.Under inert atmosphere, make required sample.

In addition, in XPS measuring, for example utilize the C1s peak to proofread and correct the energy axes of power spectrum.Because surface contamination carbon is present in material surface usually, so the C1s peak of surface contamination carbon is set in 284.8eV, uses this peak as energy reference.In XPS measuring, obtain the C1s spike shape of following form: the peak that comprises carbon in the peak of surface contamination carbon and the negative electrode active material.Thereby, for example be purchased software analysis, separately with the peak of carbon in the peak of surface contamination carbon and the negative electrode active material by use.In waveform analysis, the peak position that will be positioned at minimum binding energy side is set at energy reference (284.8eV).

For example following formation negative electrode active material: mix the raw material of each element, this mixture of fusion in electric furnace, Efco-Northrup furnace or arc-melting furnace etc. makes product solidify then.In addition, for example, form negative electrode active material by various atomization methods such as gas atomization and water atomization, various milling method or the method for utilizing mechanico-chemical reaction for example machine-alloying and mechanical milling method.Particularly, preferably form negative electrode active material by the method for utilizing mechanico-chemical reaction, this is because the negative electrode active material that obtains thus has low-crystallinity structure or non crystalline structure.For this method, for example can adopt planetary ball mill equipment.

For raw material, can mix the simple substance that uses each element.Yet the part element for beyond the de-carbon preferably uses alloy.When carbon being added in the described alloy, when synthesizing negative electrode active material by the method that adopts machine-alloying then, can obtain low-crystallinity structure or non crystalline structure, and shorten the reaction time.Raw material can be powder or block.

Carbon as raw material for example can use one or more material with carbon elements, for example difficult graphitized carbon, graphitized carbon, graphite, RESEARCH OF PYROCARBON, coke, vitreous carbon, organic polymer compounds sintered body, active carbon and carbon black.In aforementioned material with carbon element, coke comprises pitch coke, pin charcoal, petroleum coke etc.Organic polymer compounds sintered body is by in the suitable sintering temperature polymer compound carbonized bodies that obtains of phenolic resins and furane resins for example.The shape of these material with carbon elements can be fibrous, spherical, granular or flakey.

The following secondary cell that is used for of negative electrode active material for example.

First kind of secondary cell

Fig. 1 shows the cross section structure of first kind of secondary cell.The described secondary cell of the application for example is a lithium rechargeable battery, and wherein capacity of negative plates is expressed as based on inserting and deviating from capacity as the lithium of electrode reaction thing.

Secondary cell comprises spiral winding electrode 20, and wherein strip anodal 21 and strip negative pole 22 and the dividing plate between them 23 are stacked, and reels at battery case 11 inside spins of approximate hollow cylindrical.The battery structure that comprises battery case 11 is called column type.Battery case 11 is for example made by nickel-clad iron.The one end closure of battery case 11 and the other end are open.Be injected into liquid electrolyte (so-called electrolyte) in the battery case 11 and be immersed in the dividing plate 23.Arrange a pair of

insulation board

12 and 13 perpendicular to the screw winding peripheral surface respectively, make spiral winding electrode 20 be clipped between described

insulation board

12 and 13.

In the open end of battery case 11, by with packing ring 17 calkings, battery cover 14 and the relief valve mechanism 15 and PTC (positive temperature coefficient) devices 16 that are arranged in the battery cover 14 are bonded together.Thereby battery case 11 inside are hermetic sealed.Battery cover 14 for example can be by making with battery case 11 identical materials.Relief valve mechanism 15 is electrically connected with battery cover 14 by PTC device 16.In relief valve mechanism 15, if the interior pressure of secondary cell is owing to internal short-circuit, external heat etc. reaches certain level or higher, then disc plate 15A returns and scratches, thereby cuts off the electrical connection between battery cover 14 and the spiral winding electrode 20.When temperature raise, the resistance value of PTC device 16 increased, thereby the restriction electric current causes abnormal heating to avoid big electric current.Packing ring 17 is for example made by insulating material, and its surface-coated has pitch.

Spiral winding electrode 20 is that center convolution is reeled with centrepin 24 for example.The positive wire 25 that aluminium (Al) etc. is made links to each other with the positive pole 21 of spiral winding electrode 20, and the negative wire 26 that nickel (Ni) etc. is made links to each other with negative pole 22.Positive wire 25 is electrically connected with battery cover 14 by being welded on the relief valve mechanism 15.Welding negative wire 26, thus be electrically connected with battery case 11.

Fig. 2 shows the amplification part of spiral winding electrode 20 shown in Figure 1.Electrode 21 for example has following structure: wherein positive electrode active material layer 21B is arranged on the one or both sides of the positive electrode collector 21A with a pair of opposite face.Positive electrode collector 21A is for example made by metal forming such as aluminium foil.Positive electrode active material layer 21B for example comprises, and one or more can insert and deviate from the positive active material of lithium.If necessary, positive electrode active material layer 21B can comprise for example material with carbon element and binding agent polyvinylidene fluoride for example of electric conductor.

As the positive active material that can insert and deviate from lithium, for example enumerate the metal sulfide that do not comprise lithium, metal oxide etc., for example titanium sulfide (TiS ₂), molybdenum sulfide (MoS ₂), selenizing niobium (NbSe ₂) and vanadic oxide (V ₂O ₅).In addition, also enumerate and be mainly Li _xMO ₂The lithium composite xoide of (in general formula, M represents one or more transition metal, and x changes according to the charging and discharging state of secondary cell, and the x value is generally 0.05≤x≤1.1) etc.As the transition metal M that constitutes lithium composite xoide, cobalt, nickel or manganese (Mn) are preferred.As the instantiation of this lithium composite xoide, enumerate LiCoO ₂, LiNiO ₂, Li _xNi _yCo _1-yO ₂(in general formula, x and y change according to the charging and discharging state of secondary cell, and are generally 0＜x＜1,0＜y＜1), have the complex Li-Mn-oxide of spinel structure etc.

Negative pole 22 for example has following structure: wherein positive pole 21 is such as described, and negative electrode active material layer 22B is arranged on the one or both sides of the negative electrode collector 22A with a pair of opposite face.Negative electrode collector 22A is for example made by metal forming such as Copper Foil.

Negative electrode active material layer 22B for example comprises the negative electrode active material of the present embodiment.If necessary, negative electrode active material layer 22B comprises for example polyvinylidene fluoride of binding agent.Because the negative electrode active material of the present embodiment is included among the negative electrode active material layer 22B of secondary cell, thus high power capacity can be obtained, and improved cycle characteristics and initial charge/discharge efficient.Except that the negative electrode active material of the present embodiment, negative electrode active material layer 22B also can comprise for example electric conductor of other negative electrode active materials and other materials.Other negative electrode active materials for example comprise the material with carbon element that can insert and deviate from lithium.The preferred material with carbon element that uses, this is because the effect that material with carbon element can improve charge and play electric conductor.The example of material with carbon element for example comprises and the material identical materials that is used to form negative electrode active material.

The ratio of material with carbon element is preferably the 1wt%～95wt% of the negative electrode active material of the present embodiment.If the amount of material with carbon element is few, then may reduce the conductivity of negative pole 22.Equally, if the amount of material with carbon element is big, then may reduce capacity.

Dividing plate 23 separates positive pole 21 and negative pole and lithium ion is passed through, and prevents that simultaneously the contact of two electrodes from causing short circuit current.Dividing plate 23 is for example made by perforated membrane or ceramic porous membrane that synthetic resin such as polytetrafluoroethylene, polypropylene and polyethylene are made.Dividing plate 23 can have two or more porous membrane laminated structures of perforated membrane as described above.

The electrolyte that is immersed in the dividing plate 23 comprises solvent and the electrolytic salt that is dissolved in solvent.The example of solvent comprises propylene glycol carbonate, ethylene carbonate ester, diethyl carbonate, dimethyl carbonate, 1,2-dimethoxy-ethane, 1,2-diethoxyethane, gamma-butyrolacton, oxolane, 2-methyltetrahydrofuran, 1,3-dioxolanes, 4-methyl isophthalic acid, 3-dioxolanes, diethyl ether, sulfolane, methyl sulfolane, acetonitrile, ethyl cyanide, methyl phenyl ethers anisole, acetic acid esters, butyrate and propionic ester.Can use a kind of in the described solvent separately, perhaps can mix two or more that use in them.

Solvent more preferably comprises the cyclic carbonate derivative with halogen atom.Owing to can avoid the decomposition reaction of solvent in the negative pole 22 thus, so can improve cycle characteristics.The instantiation of this carbonic acid ester derivative comprises: the 4-fluoro-1 shown in the Chemical formula 1,3-dioxolanes-2-ketone, 4-two fluoro-1 shown in the Chemical formula 2,3-dioxolanes-2-ketone, shown in the chemical formula 34,5-two fluoro-1,3-dioxolanes-2-ketone, 4-two fluoro-5-fluoro-1 shown in the chemical formula 4,3-dioxolanes-2-ketone, 4-chloro-1 shown in the chemical formula 5,3-dioxolanes-2-ketone, shown in the chemical formula 64,5-two chloro-1,3-dioxolanes-2-ketone, 4-bromo-1 shown in the chemical formula 7,3-dioxolanes-2-ketone, 4-iodo-1 shown in the chemical formula 8,3-dioxolanes-2-ketone, 4-methyl fluoride-1 shown in the chemical formula 9,3-dioxolanes-2-ketone, 4-Trifluoromethyl-1 shown in the Chemical formula 10,3-dioxolanes-2-ketone, or the like.Particularly, 4-fluoro-1,3-dioxolanes-2-ketone are preferred, and this is because can obtain effect preferably thus.

Chemical formula 1

Chemical formula 2

Chemical formula 3

Chemical formula 4

Chemical formula 5

Chemical formula 6

Chemical formula 7

Chemical formula 8

Chemical formula 9

Chemical formula 10

Solvent can only be made of carbonic acid ester derivative.Yet solvent is preferably carbonic acid ester derivative and at ambient pressure (1.01325 * 10 ⁵Pa) down boiling point is at the mixture of 150 ℃ or following low boiling point solvent, and this is because improved ionic conductance thus.The content of carbonic acid ester derivative is preferably the 0.1wt%～80wt% of whole solvent.If content is little, then avoid the effect possibility of solvolysis reaction in the negative pole 22 insufficient.Yet if content is big, viscosity may increase, thereby may reduce ionic conductance.

As electrolytic salt, for example enumerate lithium salts.Can use a kind of in the lithium salts separately, perhaps can mix two or more that use in the lithium salts.The example of lithium salts comprises LiClO ₄, LiAsF ₆, LiPF ₆, LiBF ₄, LiB (C ₆H ₅) ₄, CH ₃SO ₃Li, CF ₃SO ₃Li, LiCl, LiBr etc.Although lithium salts is preferably used as electrolytic salt, using lithium salts is not the sin qua non.As long as anodal 21 grades provide enough lithium ions of discharging and recharging of helping.

For example following manufacturing secondary cell.

For example, at first mixed cathode active material and (if necessary) electric conductor and binding agent with the preparation cathode mix.Subsequently, this cathode mix is dispersed in mixed solvent for example in the N-N-methyl-2-2-pyrrolidone N-to form the cathode mix slurry.Then, utilize this cathode mix slurry to apply positive electrode collector 21A, drying is also suppressed this positive electrode collector 21A with formation positive electrode active material layer 21B, thereby forms anodal 21.Subsequently, positive wire 25 is welded on anodal 21.

In addition, for example mix negative electrode active material and (if necessary) other negative electrode active materials and the binding agent of the present embodiment, with preparation negative pole mixture.With this negative pole mixture be dispersed in mixed solvent for example in the N-N-methyl-2-2-pyrrolidone N-to form the negative pole mixture paste.Then, utilize this negative pole mixture paste to apply negative electrode collector 22A, drying is also suppressed this negative electrode collector 22A with formation negative electrode active material layer 22B, thereby forms negative pole 22.Subsequently, negative wire 26 is welded on the negative pole 22.

Then, make positive pole 21 and

negative pole

22 and 23 screw windings of the dividing plate between them.One end of positive wire 25 is welded on the relief valve mechanism 15, an end of negative wire 26 is welded on the battery case 11.Screw winding anodal 21 and screw winding negative pole 22 are clipped between a pair of

insulation board

12 and 13, and are contained in the battery case 11.Then, inject the electrolyte in the battery case 11.Subsequently, by packing ring 17 calkings, battery cover 14, relief valve mechanism 15 and PTC device 16 are fixed on the open end of battery case 11.Thereby make secondary cell illustrated in figures 1 and 2.

In secondary cell, when charging, for example lithium ion is deviate from from anodal 21 and is inserted in the negative pole 22 by electrolyte.When discharge, for example lithium ion is deviate from from negative pole 22 and is inserted in anodal 21 by electrolyte.

As mentioned above, according to the negative electrode active material of the present embodiment have can with the reacting phase of electrode reaction thing reaction, and the half-breadth of the diffraction maximum (at the observed peak, the angle of diffraction 2 θ places between 41 degree and 45 degree) that obtains by X-ray diffraction be 1.0 degree or more than.In this case, because negative electrode active material comprises first element tin, so can obtain high power capacity.In addition, negative electrode active material comprises second elemental iron and element cobalt, and the ratio of iron, cobalt summation and tin, iron, cobalt summation is 26.4wt%～48.5wt%, and the ratio of cobalt and iron, cobalt summation is 9.9wt%～79.5wt%.Thereby improved cycle characteristics.In addition, negative electrode active material comprises the 4th elemental carbon, and carbon content is 11.9wt%～29.7wt%.Thereby, further improved cycle characteristics.Thereby, compare less than the situation of cobalt content with iron content, when keeping high power capacity, obviously improved cycle characteristics.Thereby, according to the secondary cell that uses aforementioned negative electrode active material, can obtain high power capacity and can obtain good cycle characteristics.

In addition, comprise when being selected from least a in aluminium, titanium, vanadium, chromium, niobium and the tantalum at negative electrode active material as The Fifth Element, perhaps negative electrode active material comprises and is selected from least a as the hexa-atomic when plain in nickel, copper, zinc, gallium and the indium, can further improve cycle characteristics.In this case, if negative electrode active material comprises The Fifth Element and hexa-atomic element simultaneously, then can obtain better effect.Particularly, comprise The Fifth Element and hexa-atomic element simultaneously, and the content of The Fifth Element is 0.1wt%～9.9wt%, when the content of hexa-atomic element is 0.5wt%～14.9wt%, can obtains better effect at negative electrode active material.

In addition, if negative electrode active material comprises the 7th elemental silver, then can further improve cycle characteristics.Particularly, if silver content is 0.1wt%～9.9wt%, then can obtain better effect.

In addition, if negative electrode active material comprises the 5th to the 7th element simultaneously, then can further improve cycle characteristics.

Second kind of secondary cell

Fig. 3 shows the exploded perspective structure of second kind of secondary cell.In this secondary cell, the spiral winding electrode 30 with positive wire 31 and negative wire 32 on it is contained in the film packing component 40.The size of this secondary cell, weight and thickness can reduce.This secondary cell for example is and first kind of lithium ion battery that secondary cell is similar to comprise that the battery structure of film packing component 40 is called the lamination membranous type.

For example, 40 inside causes the outside to positive wire 31 along identical direction from packing component respectively with negative wire 32.Positive wire 31 and negative wire 32 for example by metal material for example aluminium, copper, nickel and stainless steel make, and be respectively plate-shaped or screen cloth shape.

Packing component 40 is made by the rectangular aluminum laminated film, and wherein for example nylon membrane, aluminium foil and polyethylene film are bonded together in this order.For example be arranged to make the polyethylene film side relative packing component 40, and external margin separately be in contact with one another by welding or binding agent with spiral winding electrode 30.Prevent that the adhensive membrane 41 that outside air enters is inserted between packing component 40 and positive wire 31 and the negative wire 32.Adhensive membrane 41 is made by the material that has an adherence with positive wire 31 and negative wire 32, is for example made by vistanex such as polyethylene, polypropylene, modified poly ethylene and modified polypropene.

Packing component 40 can be made by the laminated film with other structures, polymer film such as polypropylene or metal film, replaces aforementioned aluminium lamination press mold.

Fig. 4 shows the cross section structure of the spiral winding electrode shown in Figure 3 30 of IV-IV intercepting along the line.In this spiral winding electrode 30, positive pole 33 and negative pole 34 and the dividing plate between them 35 and dielectric substrate 36 are stacked, then screw winding.Boundary belt 37 its outermost of protection.

Anodal 33 have following structure: wherein positive electrode active material layer 33B is arranged on the one or both sides of positive electrode collector 33A.Negative pole 34 has following structure: wherein negative electrode active material layer 34B is arranged on the one or both sides of negative electrode collector 34A.Arrange so that negative electrode active material layer 34B side is relative with positive electrode active material layer 33B.The structure of positive electrode collector 33A, positive electrode active material layer 33B, negative electrode collector 34A, negative electrode active material layer 34B and dividing plate 35 is identical with dividing plate 23 with structure, positive electrode active material layer 21B, negative electrode collector 22A, the negative electrode active material layer 22B of the positive electrode collector 21A of aforementioned first kind of secondary cell.

Dielectric substrate 36 is for comprising the so-called gel of electrolyte and the polymer compound that keeps this electrolyte.Gel electrolyte is preferred, and this is because can obtain high ionic conductance thus and can be avoided the secondary cell leakage.The formation of the electrolyte in the formation of electrolyte (being solvent and electrolytic salt) and the aforementioned first kind of secondary cell is identical.As polymer compound, for example enumerate: fluorinated polymers compounds, for example copolymer of polyvinylidene fluoride and vinylidene fluoride and hexafluoropropylene; Ether polymer compound, for example poly(ethylene oxide) and the cross-linking compounds that comprises poly(ethylene oxide); Perhaps polyacrylonitrile.Particularly, with regard to oxidation-reduction stability, the fluorinated polymers compounds is desirable.

The dielectric substrate 36 that also can directly use electrolyte to replace electrolyte wherein to keep by polymer compound.In this case, electrolyte is immersed in the dividing plate 35.

For example following manufacturing comprises the secondary cell of gel electrolyte layer 36.

At first, preparation comprises the precursor solution of solvent, electrolytic salt, polymer compound and mixed solvent.Subsequently, utilize this precursor solution to apply positive pole 33 and negative pole 34 respectively, make the mixed solvent volatilization, thereby form dielectric substrate 36.Then, by welding, by welding with the end of negative wire 32 attached to negative electrode collector 34A with the end of positive wire 31 attached to positive electrode collector 33A.Then, formed positive pole 33 with dielectric substrate 36 and negative pole 34 and the dividing plate between them 35 are stacked, thereby obtain layered product.Longitudinally after this layered product of screw winding, boundary belt 37 is bonded in the outermost of this layered product, thereby forms spiral winding electrode 30.At last, for example this spiral winding electrode 30 is clipped between the packing component 40, and makes the external margin contact of packing component 40 to encapsulate this spiral winding electrode 30 by thermal welding etc.At this moment, adhensive membrane 41 is inserted between positive wire 31/ negative wire 32 and the packing component 40.Thereby, make Fig. 3 and secondary cell shown in Figure 4.

In addition, the secondary cell that can following manufacturing comprises gel electrolyte layer 36.At first, form anodal 33 and negative pole 34 as mentioned above, with positive wire 31 and negative wire 32 respectively attached to anodal 33 and negative pole 34 on.Subsequently, make positive pole 33 and negative pole 34 and the 35 stacked and screw windings of the dividing plate between them.Boundary belt 37 is bonded in its outermost, thereby forms screw winding body as the precursor of spiral winding electrode 30.Then, this screw winding body is clipped between the packing component 40, makes peripheral edge contact except that on one side obtaining a bag shape by thermal welding etc., and the screw winding body is contained in the packing component 40.Then, electrolyte, the monomer as the polymer compound raw material, polymerization initiator and (if necessary) other materials that preparation contains solvent and electrolytic salt be the composition of polymerization inhibitor for example, and said composition is injected in the packing component 40.At last, under vacuum, by thermal welding, the opening of airtight sealing packing component 40.Subsequently, make monomer polymerization to obtain polymer compound by heating.Thereby, form gel electrolyte layer 36.Thereby, make Fig. 3 and secondary cell shown in Figure 4.

This secondary cell provides and first kind of similar function of secondary cell and effect.

The third secondary cell

Fig. 5 shows the cross section structure of the third secondary cell.This secondary cell is the lithium rechargeable battery that is similar to first kind of secondary cell.In this secondary cell, plate electrode body 50 is contained in the film packing component 56, in this plate electrode body 50, relatively arranges with the positive pole 52 of positive wire 51 with the negative pole 54 of negative wire 53, arranges dielectric substrate 55 between them.The structure of the packing component 40 in the structure of packing component 56 and the aforementioned second kind of secondary cell is identical.

Anodal 52 have following structure: wherein positive electrode collector 52A is provided with positive electrode active material layer 52B.Negative pole 54 has following structure: wherein negative electrode collector 54A is provided with anode active material layer 54B.Arrange so that negative electrode active material layer 54B side is relative with positive electrode active material layer 52B.The structure of positive electrode collector 52A, positive electrode active material layer 52B, negative electrode collector 54A and negative electrode active material layer 54B respectively with above-mentioned first kind of secondary cell in positive electrode collector 21A, positive electrode active material layer 21B, negative electrode collector 22A identical with negative electrode active material layer 22B.

Dielectric substrate 55 is for example made by solid electrolyte.As solid electrolyte, for example can use inorganic solid electrolyte or copolymer solid electrolyte, as long as this solid electrolyte is the material with lithium-ion-conducting.As inorganic solid electrolyte, enumerate the electrolyte that comprises lithium nitride, lithium iodide etc.Copolymer solid electrolyte is for mainly comprising the electrolyte of the electrolytic salt and the polymer compound of dissolving electrolytic salt.As the polymer compound of copolymer solid electrolyte, can use separately, mix and use or for example use: ether polymer compound, for example poly(ethylene oxide) and the cross-linking compounds that comprises poly(ethylene oxide) by copolymerization; Esters polymer compound, for example polymethacrylates; The acrylic polymer compound; Or the like.

For example can make the mixed solvent volatilization then, form copolymer solid electrolyte by mixed polymerization compounds, electrolytic salt and mixed solvent.In addition, can by with electrolytic salt, as the polymer compound raw material monomer, polymerization initiator and (if necessary) other materials for example polymerization inhibitor be dissolved in mixed solvent, make the mixed solvent volatilization, heating is so that monomer polymerization and obtain polymer compound forms copolymer solid electrolyte then.

For example pass through for example sputtering method, vacuum vapour deposition, laser ablation method, ion plating method and CVD (chemical vapour deposition (CVD)) method of vapour deposition process, perhaps liquid phase deposition sol-gal process for example, for example anodal 52 or the surface of negative pole 54 on form inorganic solid electrolyte.

This secondary cell provides function and the effect that is similar to first kind or second kind secondary cell.

Embodiment

In addition, will describe specific embodiments of the invention in detail.

Embodiment 1-1～1-7

At first, form negative electrode active material.Promptly prepare glass putty, iron powder, cobalt powder and carbon dust as raw material.Glass putty, iron powder and cobalt powder are carried out alloying, thereby obtain tin-iron-cobalt alloy powder, add to carbon dust in this tin-iron-cobalt alloy powder and product is done mixed.Change material rate (material rate: wt%) as shown in table 1.Particularly, the ratio (ratio that after this is called (Fe+Co)/(Sn+Fe+Co)) with iron, cobalt summation and tin, iron, cobalt summation is made as steady state value 32wt%.The ratio (ratio that after this is called Co/ (Fe+Co)) of cobalt and iron, cobalt summation is made as steady state value 50wt%.The carbon material rate is changed in 12wt%～30wt% scope.Subsequently, the corundum that the aforementioned mixture of 20g and about 400g diameter are 9mm is put into ITO Seisakusho Co. together, in the reaction vessel of the planetary ball mill of Ltd..Subsequently, after reaction vessel interior was occupied by argon gas (Ar) atmosphere, every interval 10 minutes reached 30 hours with the rotation speed operation of 250rpm 10 minutes up to total run time (reaction time).At last, reaction vessel is cooled to room temperature, takes out the negative electrode active material powder that is synthesized, remove meal by 280 purpose screen clothes.

Table 1

(Fe+Co)/(Sn+Fe+Co)＝32wt％，Co/(Fe+Co)＝50wt％

Analyze the composition of gained negative electrode active material.Measure carbon content by carbon-sulphur analyzer, measure tin content, iron content and cobalt content by ICP (inductively coupled plasma) emission spectra.(wt%) is as shown in table 1 for assay value.All material rates shown in the table 1 and assay value are second value that rounds up and obtain behind the decimal point.This is equally applicable to subsequently a series of embodiment and comparative example.

In addition, for the negative electrode active material of gained, carry out X-ray diffraction.As a result, in 2 θ=20～50 degree scopes, observe two diffraction maximums.Wherein, the half-breadth of observed diffraction maximum is as shown in table 1 in 2 θ=41～45 degree scopes.In addition, the bonding state by the element in the XPS measuring negative electrode active material.As a result, as shown in Figure 6, obtain peak P1.When peak P1 is analyzed, obtain the peak P2 of surface contamination carbon, a side that is lower than peak P2 at energy obtains the peak P3 of C1s in the negative electrode active material.For whole embodiment 1-1～1-7, all in being lower than the zone of 284.5eV, obtain peak P3.Promptly confirmed carbon and other element bondings in the negative electrode active material.

Then, use aforementioned positive electrode active material powder to make Coin shape secondary cell shown in Figure 7.In this secondary cell, use the test electrode 61 of described negative electrode active material to be contained in the anode cover 62, to electrode 63 attached on the negative electrode casing 64.These parts and to be soaked with the dividing plate 65 of electrolyte between them stacked utilize packing ring 66 calkings then.When preparation during test electrode 61, mix 70 weight portion negative electrode active material powder, 20 weight portions as the graphite of electric conductor and other negative electrode active materials, 1 weight portion as the acetylene black of electric conductor and 4 weight portions polyvinylidene fluoride as binding agent.This mixture is dispersed in the suitable solvent, thereby obtains slurry.Subsequently, utilize this slurry to apply the Copper Foil collector body, dry then.Products therefrom is washed into the sheet of diameter 15.2mm.As to electrode 63, use the metal lithium sheet that is washed into diameter 15.5mm.Mixed carbonic acid glycol ester (EC), propylene glycol carbonate (PC) and dimethyl carbonate (DMC), thus mixed solvent obtained, will be as the LiPF of electrolytic salt ₆Be dissolved in this mixed solvent, and products therefrom is used as electrolyte.Described mixed solvent consists of EC: PC: DMC=30: 10: 60 (weight ratio), the concentration of electrolytic salt are 1mol/dm ³

Check the initial charge capacity (mAh/g) of this Coin shape secondary cell.As initial charge capacity, under the constant current of 1mA, carry out constant current charge, reach 0.2mV up to cell voltage.Subsequently, under the constant voltage of 0.2mV, carry out constant voltage charge, reach 10 μ A up to electric current.Then, obtain the charging capacity of Unit Weight (deducting the weight of Copper Foil collector body and binding agent in the test electrode 61)." charging " is meant the insertion reaction of lithium and negative electrode active material in this application.Result such as table 1 and shown in Figure 8.

In addition, use aforementioned negative electrode active material powder to make cylinder type secondary battery illustrated in figures 1 and 2.Promptly according to nickel oxide: Ketjen is black: polyvinylidene fluoride=94: 3: 3 (weight ratio), mix the positive active material that comprises nickel oxide, black as the Ketjen of electric conductor, as the polyvinylidene fluoride of binding agent.This mixture is dispersed in the mixed solvent N-N-methyl-2-2-pyrrolidone N-, thereby obtains the cathode mix slurry.Then, utilize this positive pole mixed slurry to apply the two sides of the positive electrode collector 21A that the strip aluminium foil makes equably, and carry out drying.Then, by roll squeezer products therefrom is pressed to form positive electrode active material layer 21B.Thereby form anodal 21.Subsequently, with on the end of aluminum positive wire 25 attached to positive electrode collector 21A.

In addition, utilize the negative pole mixture paste comprise aforementioned negative electrode active material to apply the two sides of the negative electrode collector 22A that the strip Copper Foil makes equably, and carry out drying.Then, by roll squeezer products therefrom is pressed to form negative electrode active material layer 22B.Thereby form negative pole 22.Subsequently, with on the end of nickel system negative wire 26 attached to negative electrode collector 22A.

Then, make dividing plate 23.Negative pole 22, dividing plate 23, positive pole 21 and dividing plate 23 are stacked in this order.Gained layered product screw winding several times, thereby form spiral winding electrode 20.Then, this spiral winding electrode 20 is clipped between a pair of insulation board 12 and 13.Negative wire 26 is welded on the battery case 11, positive wire 25 is welded on the relief valve mechanism 15.Subsequently, this spiral winding electrode 20 is installed in the battery case 11 that nickel-clad iron makes.At last, by the decompression method aforementioned electrolyte is injected in this battery case 11, thereby makes cylinder type secondary battery.

Check the cycle characteristics of this cylinder type secondary battery.In this case, at first, under the constant current of 0.5A, carry out constant current charge after cell voltage reaches 4.2V, under the constant voltage of 4.2V, carry out constant voltage charge, reach 10mA up to electric current.Then, under the constant current of 0.25A, carry out constant-current discharge, reach 2.6V, thereby finish charge and discharge cycles the 1st time up to cell voltage.After the 2nd circulation and the 2nd circulation, under the constant current of 1.4A, carry out constant current charge after cell voltage reaches 4.2V, under the constant voltage of 4.2V, carry out constant voltage charge, reach 10mA up to electric current.Then, under the constant current of 1.0A, carry out constant-current discharge, reach 2.6V up to cell voltage.Subsequently, obtain the ratio of discharge capacity with the discharge capacity of the 2nd circulation time of the 300th circulation time, i.e. capability retention (%)=(discharge capacity of the discharge capacity of the 300th circulation time/2nd time circulation time) * 100 are with the check cycle characteristics.Result such as table 1 and shown in Figure 8.

As comparative example 1-1 with respect to embodiment 1-1～1-7, form negative electrode active material and secondary cell in the mode identical with embodiment 1-1～1-7, different is not use carbon dust as raw material.1-2～1-5 forms negative electrode active material and secondary cell in the mode identical with embodiment 1-1～1-7 as a comparative example, and different is change carbon material rate as shown in table 1.

For the negative electrode active material of comparative example 1-1～1-5, measure the half-breadth of observed diffraction maximum in 2 θ=41～45 degree scopes.The result is as shown in table 1.In addition, when passing through the bonding state of XPS measuring element, in comparative example 1-2～1-5, obtain peak P1 shown in Figure 6.When peak P1 is analyzed, as in embodiment 1-1～1-7, obtain the peak P3 of C1s in the peak P2 of surface contamination carbon and the negative electrode active material, for all comparative examples, all in being lower than the zone of 284.5eV, obtain peak P3.Promptly confirmed at least a portion and other element bondings of contained carbon in the negative electrode active material.Yet, in comparative example 1-1, as shown in Figure 9, obtain peak P4.When P4 is analyzed, only obtain the peak P2 of surface contamination carbon.

In addition, for the secondary cell of comparative example 1-1～1-5, check initial charge capacity and cycle characteristics in the mode identical with embodiment 1-1～1-7.Result such as table 1 and shown in Figure 8.

Prove as table 1 and Fig. 8, carbon content is among embodiment 1-1～1-7 of 11.9wt%～29.7wt% in negative electrode active material, compare at the comparative example 1-1～1-5 beyond the described scope with carbon content, the capability retention of embodiment 1-1～1-7 has obtained more significantly improving, and initial charge capacity also is improved.In this case, when carbon content be 14.9wt% or more than, 17.8wt% or when above, capability retention and initial charge capacity are further improved more preferably.Particularly, in all embodiment 1-1～1-7, half-breadth be 1.00 the degree or more than.

If find that promptly carbon content is 11.9wt%～29.7wt%, then capacity and cycle characteristics can improve.Find that also carbon content is preferably 14.9wt%～29.7wt%, more preferably 17.8wt%～29.7wt%.

Embodiment 2-1～2-8

Form negative electrode active material and secondary cell in the mode identical with embodiment 1-1～1-7, different is the material rate of change tin as shown in table 2, iron, cobalt and carbon.Particularly, the carbon material rate is made as steady state value 18wt%, the ratio of Co/ (Fe+Co) is made as steady state value 50wt%, and the ratio of (Fe+Co)/(Sn+Fe+Co) is changed in 26wt%～48wt% scope.

Table 2

Co/(Fe+Co)＝50wt％

Comparative example 2-4	20.1	20.1	41.8	18	20.3	20	41.6	17.8	49.2	3.21	429.9	68
													Comparative example 2-5	20.5	20.5	41	18	20.9	20.4	40.7	17.8	50.4	3.54	401.5	69

As comparative example 2-1～2-5 with respect to embodiment 2-1～2-8, form negative electrode active material and secondary cell in the mode identical with embodiment 2-1～2-8, different is the ratio of change as shown in table 2 (Fe+Co)/(Sn+Fe+Co).

For the negative electrode active material of embodiment 2-1～2-8 and comparative example 2-1～2-5, analyze their composition in the mode identical with embodiment 1-1～1-7.The result is as shown in table 2.In addition, the anticathode active material carries out X-ray diffraction, measures the half-breadth of observed diffraction maximum in 2 θ=41～45 degree scopes.The result is also as shown in table 2.In addition, when analyzing, obtain the peak P3 of C1s in the peak P2 of surface contamination carbon and the negative electrode active material,, all in being lower than the zone of 284.5eV, obtain peak P3 for all embodiment by the resulting peak of XPS measuring negative electrode active material.Promptly confirmed at least a portion and other element bondings of contained carbon in the negative electrode active material.In addition, with the initial charge capacity and the cycle characteristics of the mode detecting secondary battery identical with embodiment 1-1～1-7.Result such as table 2 and shown in Figure 10.

Prove as table 2 and Figure 10, ratio at (Fe+Co)/(Sn+Fe+Co) is among embodiment 2-1～2-8 of 26.4wt%～48.5wt%, compare with the comparative example 2-1～2-3 of ratio below 26.4wt% of (Fe+Co)/(Sn+Fe+Co), the capability retention of embodiment 2-1～2-8 has obtained more significantly improving, comparative example 2-4 greater than 48.5wt% compares with 2-5 with the ratio of (Fe+Co)/(Sn+Fe+Co), and the initial charge capacity of embodiment 2-1～2-8 has obtained bigger improvement.In this case, if ratio (Fe+Co)/(Sn+Fe+Co) be 29.2wt% or more than, then capability retention is higher, particularly, in all embodiment 2-1～2-8, half-breadth be 1.00 the degree or more than.

If find that promptly ratio (Fe+Co)/(Sn+Fe+Co) is 26.4wt%～48.5wt%, then capacity and cycle characteristics can improve.The ratio of also finding (Fe+Co)/(Sn+Fe+Co) is 29.2wt%～48.5wt% more preferably.

Embodiment 3-1～3-7

Form negative electrode active material and secondary cell in the mode identical with embodiment 1-1～1-7, different is the material rate of change tin as shown in table 3, iron, cobalt and carbon.Particularly, the carbon material rate is made as steady state value 18wt%, the ratio of (Fe+Co)/(Sn+Fe+Co) is set at steady state value 32wt%, the ratio of Co/ (Fe+Co) is changed in 10wt%～80wt% scope.

Table 3

(Fe+Co)/(Sn+Fe+Co)＝32wt％

As comparative example 3-1～3-4 with respect to embodiment 3-1～3-7, form negative electrode active material and secondary cell in the mode identical with embodiment 3-1～3-7, different is the ratio of change Co/ as shown in table 3 (Fe+Co).

For the negative electrode active material of embodiment 3-1～3-7 and comparative example 3-1～3-4, their composition is analyzed in the mode identical with embodiment 1-1～1-7.The result is as shown in table 3.In addition, the anticathode active material carries out X-ray diffraction, measures the half-breadth of observed diffraction maximum in 2 θ=41～45 degree scopes.The result is also as shown in table 3.In addition, when analyzing the peak that obtains by the XPS measuring negative electrode active material,, obtain the peak P3 of C 1s in the peak P2 of surface contamination carbon and the negative electrode active material as in embodiment 1-1～1-7, for all embodiment, all in being lower than the zone of 284.5eV, obtain peak P3.Promptly confirmed at least a portion and other element bondings of contained carbon in the negative electrode active material.In addition, with the initial charge capacity and the cycle characteristics of the mode detecting secondary battery identical with embodiment 1-1～1-7.Result such as table 3 and shown in Figure 11.

Prove as table 3 and Figure 11, ratio at Co/ (Fe+Co) is among embodiment 3-1～3-7 of 9.9wt%～79.5wt%, the comparative example 3-1 that is lower than 9.9wt% with the ratio of Co/ (Fe+Co) compares with 3-2, the capability retention of embodiment 3-1～3-7 has obtained bigger improvement, comparative example 3-3 greater than 79.5wt% compares with 3-4 with the ratio of Co/ (Fe+Co), and the initial charge capacity of embodiment 3-1～3-7 has obtained bigger improvement.In this case, if the ratio of Co/ (Fe+Co) be 29.5wt% or more than, then capability retention is higher.Particularly, in all embodiment 3-1～3-7, half-breadth be 1.00 the degree or more than.

If when finding that promptly the ratio of Co/ (Fe+Co) is 9.9wt%～79.5wt%, then capacity and cycle characteristics can improve.The ratio of also finding Co/ (Fe+Co) is 29.5wt%～79.5wt% more preferably.

Embodiment 4-1～4-17

In the mode identical, form negative electrode active material and secondary cell, different glass putty, iron powder, cobalt powder and the carbon dusts of being to use with embodiment 1-1～1-7; Aluminium powder, titanium valve, vanadium powder, chromium powder, niobium powder or tantalum powder; With nickel powder, copper powder, indium powder, zinc powder or gallium powder as raw material, and the material rate of change tin as shown in table 4, iron, cobalt, carbon, aluminium etc. and nickel etc.Particularly, the carbon material rate is made as steady state value 18wt%, the ratio of (Fe+Co)/(Sn+Fe+Co) is made as steady state value 32wt%, the ratio of Co/ (Fe+Co) is made as steady state value 50wt%, and suitably changes the material rate of aluminium etc. and nickel etc.When forming negative electrode active material,, thereby obtain tin-iron-cobalt alloy powder with glass putty, iron powder and cobalt powder alloying.Subsequently, with carbon dust, aluminium powder etc. and nickel powder etc. and described tin-iron-cobalt alloy powder.For the negative electrode active material of embodiment 4-1～4-17, analyze their composition in the mode identical with embodiment 1-1～1-7.Measure the content of aluminium etc. and nickel etc. by the ICP emission spectra.The result is as shown in table 5.In addition, the anticathode active material carries out X-ray diffraction, measures the half-breadth of observed diffraction maximum in 2 θ=41～45 degree scopes.The result is as shown in table 6.In addition, when analyzing the peak that obtains by the XPS measuring negative electrode active material,, obtain the peak P3 of C1s in the peak P2 of surface contamination carbon and the negative electrode active material,, all in being lower than the zone of 284.5eV, obtain peak P3 for all embodiment as embodiment 1-1～1-7.Promptly confirmed at least a portion and other element bondings of contained carbon in the negative electrode active material.In addition, with the mode identical, the initial charge capacity of detecting secondary battery and cycle characteristics with embodiment 1-1～1-7.Result such as table 6, Figure 12 and shown in Figure 13.

Table 4

(Fe+Co)/(Sn+Fe+Co)＝32wt％，Co/(Fe+Co)＝50wt％

Table 5

(Fe+Co)/(Sn+Fe+Co)＝32wt％，Co/(Fe+Co)＝50wt％

Table 6

(Fe+Co)/(Sn+Fe+Co)＝32wt％，Co/(Fe+Co)＝50wt％

	Half-breadth (degree)	Initial charge capacity (mAh/g)	Capability retention (%)
				Embodiment 1-3	1.66	621.3	56
Embodiment 4-1	1.70	598.3	65

Embodiment 4-2	1.69	603	62
				Embodiment 4-3	1.69	605.3	61
Embodiment 4-4	1.72	593.4	61
				Embodiment 4-5	1.70	599.7	65
Embodiment 4-6	1.69	604.6	67
				Embodiment 4-7	1.69	602.8	65
Embodiment 4-8	1.73	592.1	61
				Embodiment 4-9	1.69	604.2	62
Embodiment 4-10	1.68	606.8	61
				Embodiment 4-11	1.68	610.5	57
Embodiment 4-12	1.69	604.6	61
				Embodiment 4-13	1.68	606.1	60
Embodiment 4-14	1.67	612.3	60
				Embodiment 4-15	1.68	609.5	60
Embodiment 4-16	1.71	610.3	60
				Embodiment 4-17	1.72	604	56

Prove as table 4～table 6, only comprise aluminium etc. only comprise nickel etc. or comprise aluminium etc. simultaneously and the embodiment 4-1～4-7 of nickel etc. in, with do not comprise the embodiment 1-3 with nickel etc. such as aluminium and compare, when initial charge capacity kept equating substantially, the raising of capability retention was equal to or greater than embodiment 1-3.In this case, as table 4～table 6 and Figure 12,13 prove that get Ti content as the representative in aluminium etc. and get copper content as the representative in nickel etc., the capability retention when comprising titanium and copper simultaneously is higher than and only comprises the capability retention when a kind of in titanium and the copper.In addition, comprise at the same time under the situation of titanium and copper, if Ti content is 0.1wt%～9.9wt%, copper content is 0.5wt%～14.9wt%, and then capability retention is higher.Particularly, in all embodiment 4-1～4-17, half-breadth be 1.00 the degree or more than.

Be selected from least a in aluminium, titanium, vanadium, chromium, niobium and the tantalum if find promptly that negative electrode active material comprises; Perhaps negative electrode active material comprises and is selected from least a in nickel, copper, zinc, gallium and the indium; Perhaps negative electrode active material comprises the material in above-mentioned two groups simultaneously, then can further improve cycle characteristics.In addition, find that the situation that negative electrode active material comprises the material in above-mentioned two groups simultaneously is preferred.In this case, the content of finding aluminium etc. is that the content of 0.1wt%～9.9wt% and nickel etc. is that 0.5wt%～14.9wt% is preferred.

Embodiment 5-1～5-9

Form negative electrode active material and secondary cell in the mode identical with embodiment 1-1～1-7, different is to prepare glass putty, iron powder, cobalt powder, carbon dust and silver powder as raw material, and change material rate as shown in table 7.Particularly, the carbon material rate is made as steady state value 18wt%, the ratio of (Fe+Co)/(Sn+Fe+Co) is made as steady state value 32wt%, the ratio of Co/ (Fe+Co) is made as steady state value 50wt%, the silver material ratio is changed in 0.1wt%～15wt% scope.When forming negative electrode active material, after obtaining tin-iron-cobalt alloy powder, make carbon dust and silver powder and described tin-iron-cobalt alloy powder at alloying glass putty, iron powder and cobalt powder.For the negative electrode active material of embodiment 5-1～5-9, analyze its composition in the mode identical with embodiment 1-1～1-7.Measure silver content by the ICP emission spectra.The result is as shown in table 7.In addition, the anticathode active material carries out X-ray diffraction, measures the half-breadth of observed diffraction maximum in 2 θ=41～45 degree scopes.The result is also as shown in table 7.In addition, when analyzing the peak that obtains by the XPS measuring negative electrode active material,, obtain the peak P3 of C1s in the peak P2 of surface contamination carbon and the negative electrode active material,, all in being lower than the zone of 284.5eV, obtain peak P3 for all embodiment as embodiment 1-1～1-7.Promptly confirmed at least a portion and other element bondings of contained carbon in the negative electrode active material.In addition, with the initial charge capacity and the cycle characteristics of the mode detecting secondary battery identical with embodiment 1-1～1-7.Result such as table 7 and shown in Figure 14.

Table 7

(Fe+Co)/(Sn+Fe+Co)＝32wt％，Co/(Fe+Co)＝50wt％

Embodiment 5-8	11.2	11.2	47.6	18	12	11.3	11.1	47.4	17.8	11.8	1.76	614.7	63
														Embodiment 5-9	10.7	10.7	45.6	18	15	10.8	10.6	45.4	17.8	14.7	1.78	613.2	63

Prove that as table 7 and Figure 14 the embodiment 5-1～5-9 that comprises silver compares with the embodiment 1-3 that does not comprise silver, when initial charge capacity keeps basic equating, has improved capability retention.In this case, be 0.1wt%～9.9wt% at silver content, when more especially being 0.9wt%～9.9wt%, capability retention is higher.Particularly, in all embodiment 5-1～5-9, half-breadth be 1.00 the degree or more than.

Promptly find to comprise under the situation of silver, can further improve cycle characteristics at negative electrode active material.In addition, find that silver content is preferably 0.1wt%～9.9wt%, more preferably 0.9wt%～9.9wt%.

Embodiment 6-1～6-10

Form negative electrode active material and secondary cell in the mode identical, different glass putty, iron powder, cobalt powder and the carbon dusts of being to use with embodiment 1-1～1-7; Silver powder, aluminium powder, titanium valve, vanadium powder, chromium powder, niobium powder or tantalum powder; With nickel powder, copper powder, indium powder, zinc powder or gallium powder as raw material, the material rate of change tin as shown in table 8, iron, cobalt, carbon, silver, aluminium etc. and nickel etc.Particularly, the carbon material rate is made as steady state value 18wt%, the silver material ratio is made as steady state value 1wt%, the ratio of (Fe+Co)/(Sn+Fe+Co) is made as steady state value 32wt%, the ratio of Co/ (Fe+Co) is made as steady state value 50wt%, and aluminium etc. suitably change with the material rate of nickel etc.When forming negative electrode active material, at alloying glass putty, iron powder and cobalt powder and after obtaining tin-iron-cobalt alloy powder, make carbon dust, silver powder, aluminium powder etc. and nickel powder etc. and described tin-iron-cobalt alloy powder.For the negative electrode active material of embodiment 6-1～6-10, analyze their composition in the mode identical with embodiment 1-1～1-7.The result is as shown in table 9.In addition, the anticathode active material carries out X-ray diffraction, measures the half-breadth in 2 θ=observed diffraction maximum of 41～45 degree.The result is as shown in table 10.In addition, when analyzing the peak that obtains by the XPS measuring negative electrode active material,, obtain the peak P3 of C1s in the peak P2 of surface contamination carbon and the negative electrode active material as embodiment 1-1～1-7, and, all in being lower than the zone of 284.5eV, obtain peak P3 for all embodiment.Promptly confirmed at least a portion and other element bonding of institute's carbon containing in the negative electrode active material.In addition, with the initial charge capacity and the cycle characteristics of the mode detecting secondary battery identical with embodiment 1-1～1-7.The result is as shown in table 10.

Table 8

(Fe+Co)/(Sn+Fe+Co)＝32wt％，Co/(Fe+Co)＝50wt％

Table 9

(Fe+Co)/(Sn+Fe+Co)＝32wt％，Co/(Fe+Co)＝50wt％

Table 10

(Fe+Co)/(Sn+Fe+Co)＝32wt％，Co/(Fe+Co)＝50wt％

	Half-breadth (degree)	Initial charge capacity (mAh/g)	Capability retention (%)
				Embodiment 1-3	1.66	621.3	56
Embodiment 5-3	1.69	620.8	60
				Embodiment 6-1	1.71	614.7	64
Embodiment 6-2	1.70	614.3	63
				Embodiment 6-3	1.82	598.6	67
Embodiment 6-4	1.74	608.1	69
				Embodiment 6-5	1.73	609.3	68
Embodiment 6-6	1.77	606.5	68

Embodiment 6-7	1.72	609.5	67
				Embodiment 6-8	1.72	606.9	67
Embodiment 6-9	1.70	610.6	66

Embodiment 6-10

1.73

607.7

67

Prove as table 8～table 10, in the embodiment 6-1～6-10 that comprises silver, aluminium etc. and nickel etc., compare with the embodiment 1-3 that does not comprise silver, aluminium etc. and nickel etc. or compare, when initial charge capacity keeps basic equating, improved capability retention with the embodiment 5-3 that only comprises silver.Particularly, in all embodiment 6-1～6-10, half-breadth be 1.00 the degree or more than.

Promptly find to comprise silver, be selected from least a in aluminium, titanium, vanadium, chromium, niobium and the tantalum, when being selected from least a in nickel, copper, zinc, gallium and the indium, can further improve cycle characteristics at negative electrode active material.

Embodiment 7-1～7-5

Form negative electrode active material and secondary cell in the mode identical with embodiment 1-3, different is the reaction time of passing through to change when synthesizing negative electrode active material as shown in table 11 to change degree of crystallinity (half-breadth).Particularly, the carbon material rate is made as steady state value 18wt%, the ratio of (Fe+Co)/(Sn+Fe+Co) is made as steady state value 32wt%, the ratio of Co/ (Fe+Co) is made as steady state value 50wt%, and half-breadth be 1.00 degree or more than.

Table 11

(Fe+Co)/(Sn+Fe+Co)＝32wt％，Co/(Fe+Co)＝50wt％

As comparative example 4-1 and 4-2 with respect to embodiment 7-1～7-5, form negative electrode active material and secondary cell in the mode identical with embodiment 1-3, different is change reaction time as shown in table 11 and half-breadth.

For the negative electrode active material of embodiment 7-1～7-5 and comparative example 4-1,4-2, in the mode identical with embodiment 1-1～1-7, the anticathode active material carries out X-ray diffraction, measures the half-breadth in 2 θ=observed diffraction maximum of 41～45 degree.The result is as shown in table 11.In addition, when analyzing the peak that obtains by the XPS measuring negative electrode active material,, obtain the peak P3 of C1s in the peak P2 of surface contamination carbon and the negative electrode active material as embodiment 1-1～1-7, and, all in being lower than the zone of 284.5eV, obtain peak P3 for all embodiment.Promptly confirmed at least a portion and other element bonding of gained carbon in the negative electrode active material.In addition, with the initial charge capacity and the cycle characteristics of the mode detecting secondary battery identical with embodiment 1-1～1-7.Result such as table 11 and shown in Figure 15.

Proving as table 11 and Figure 15, is that the comparative example 4-1 less than 1.00 degree compare with 4-2 with half-breadth among 1.00 degree or the above embodiment 7-1～7-5 in half-breadth, and capability retention and initial charge capacity have obtained improving more significantly.

If promptly confirmed half-breadth be 1.00 the degree or more than, then can improve capacity and cycle characteristics.

Thereby, prove as table 1～table 11, Fig. 8 and Figure 10～result shown in Figure 15, if confirmed negative electrode active material have can with the reacting phase of reaction such as lithium, wherein the half-breadth of the diffraction maximum (at the observed peak, the angle of diffraction 2 θ places between 41～45 degree) that obtains of the X-ray diffraction by the anticathode active material be 1.0 degree or more than; Negative electrode active material comprises tin, iron, cobalt and carbon at least; Carbon content is 11.9wt%～29.7wt%; The ratio of iron, cobalt summation and tin, iron, cobalt summation is 26.4wt%～48.5wt%; With the ratio of cobalt and iron, cobalt summation be 9.9wt%～79.5wt%, then capacity and cycle characteristics improve.

Reference implementation scheme and embodiment describe the present invention.Yet, the invention is not restricted to the aspect described in previous embodiments and the previous embodiment, and can carry out various improvement.For example, in previous embodiments and previous embodiment, the lithium rechargeable battery as a kind of secondary cell type is illustrated, wherein capacity of negative plates is expressed as based on the capacity that inserts and deviate from lithium.Yet, the invention is not restricted to this.Secondary cell of the present invention can be applicable to following secondary cell equally: wherein capacity of negative plates comprises based on inserting and deviating from the capacity of lithium and based on the capacity of separating out with dissolving lithium, and be made as value by the charging capacity that can insert and deviate from the negative material of lithium, capacity of negative plates be expressed as the summation of aforementioned capacity less than anodal charging capacity.

In addition, in previous embodiments and previous embodiment, be that the secondary cell of column type, laminated-type, sheet type or Coin shape or secondary cell that component structure is the screw winding structure are illustrated to battery structure.Yet secondary cell of the present invention can be applicable to equally: have the secondary cell of other battery structure, for example button type secondary cell and rectangular secondary cell; The secondary cell that perhaps has the stacked laminar structure of for example a plurality of positive poles of other component structure and a plurality of negative pole.

In addition, in previous embodiments and previous embodiment, be illustrated as the situation of electrode reaction thing using lithium.Yet the present invention can be applicable to following situation: use in the long period table other 1 family element for example sodium (Na) and potassium (K); For example magnesium and calcium (Ca) of 2 family's elements in the long period table; Other light metal is aluminium for example; The perhaps alloy of lithium alloy or aforementioned elements.In this case, can obtain identical effect.Can select to insert and to deviate from the positive active material, nonaqueous solvents etc. of electrode reaction thing according to the electrode reaction thing.

In addition, in previous embodiments and previous embodiment, the optimum range of carbon content in the negative electrode active material of the present invention released by embodiment result or the secondary cell is illustrated.Yet the possibility of described content outside aforementioned range do not got rid of in this explanation fully.Be that aforementioned optimum range only is for obtaining the special preferable range of effect of the present invention.As long as can obtain effect of the present invention, carbon content can depart from aforementioned range slightly.This point is not limited to above-mentioned carbon content, also be equally applicable to the half-breadth of diffraction maximum (the observed peaks, the angle of diffraction 2 θ places between 41～45 degree) by the X-ray diffraction acquisition, be applicable to the ratio of iron, cobalt summation and tin, iron, cobalt summation, be applicable to the ratio of cobalt and iron, cobalt summation, be applicable to content, silver content of the content, nickel etc. of aluminium etc. etc.

One skilled in the art will appreciate that as long as in the scope of claims or its equivalent, can carry out various improvement, combination according to designing requirement and other factors, subgroup is closed and change.

Claims

1. a negative electrode active material comprises tin (Sn), iron (Fe), cobalt (Co) and carbon (C) element at least, wherein:

Carbon content is 11.9wt%～29.7wt%, and the ratio of iron, cobalt summation and tin, iron, cobalt summation is 26.4wt%～48.5wt%, and the ratio of cobalt and iron, cobalt summation is 9.9wt%～79.5wt%;

Comprise can with the reacting phase of electrode reaction thing reaction; With

The diffraction maximum that obtains by X-ray diffraction, i.e. observed peak, the angle of diffraction 2 θ places between 41 degree and 45 degree, half-breadth be 1.0 degree or more than.

2. according to the negative electrode active material of claim 1, wherein in being lower than the zone of 284.5eV, obtain the 1s peak of carbon by the x-ray photoelectron power spectrum.

3. according to the negative electrode active material of claim 1, also comprise at least a element that is selected from aluminium (Al), titanium (Ti), vanadium (V), chromium (Cr), niobium (Nb) and the tantalum (Ta).

4. according to the negative electrode active material of claim 1, also comprise at least a element that is selected from nickel (Ni), copper (Cu), zinc (Zn), gallium (Ga) and the indium (In).

5. according to the negative electrode active material of claim 1, also comprise at least a element that is selected from aluminium, titanium, vanadium, chromium, niobium and the tantalum; With at least a element that is selected from nickel, copper, zinc, gallium and the indium.

6. according to the negative electrode active material of claim 5, at least a content that wherein is selected from aluminium, titanium, vanadium, chromium, niobium and the tantalum is 0.1wt%～9.9wt%.

7. according to the negative electrode active material of claim 5, at least a content that wherein is selected from nickel, copper, zinc, gallium and the indium is 0.5wt%～14.9wt%.

8. according to the negative electrode active material of claim 1, also comprise silver (Ag) element.

9. negative electrode active material according to Claim 8, wherein silver content is 0.1wt%～9.9wt%.

10. according to the negative electrode active material of claim 1, also comprise at least a element that is selected from aluminium, titanium, vanadium, chromium, niobium and the tantalum; Be selected from least a element in nickel, copper, zinc, gallium and the indium; And silver element.

11. a secondary cell comprises positive pole, negative pole and electrolyte, wherein:

Described negative pole comprises negative electrode active material, and this negative electrode active material comprises tin, iron, cobalt and carbon at least;

Carbon content in this negative electrode active material is 11.9wt%～29.7wt%, and the ratio of iron, cobalt summation and tin, iron, cobalt summation is 26.4wt%～48.5wt%, and the ratio of cobalt and iron, cobalt summation is 9.9wt%～79.5wt%;

Comprise can with the reacting phase of electrode reaction thing reaction; With

12., wherein in being lower than the zone of 284.5eV, obtain the 1s peak of carbon by the x-ray photoelectron power spectrum according to the secondary cell of claim 11.

13. according to the secondary cell of claim 11, wherein said negative electrode active material also comprises at least a element that is selected from aluminium, titanium, vanadium, chromium, niobium and the tantalum.

14. according to the secondary cell of claim 11, wherein said negative electrode active material also comprises at least a element that is selected from nickel, copper, zinc, gallium and the indium.

15. according to the secondary cell of claim 11, wherein said negative electrode active material also comprises at least a element that is selected from aluminium, titanium, vanadium, chromium, niobium and the tantalum; With at least a element that is selected from nickel, copper, zinc, gallium and the indium.

16. according to the secondary cell of claim 15, at least a content that wherein is selected from described negative electrode active material in aluminium, titanium, vanadium, chromium, niobium and the tantalum is 0.1wt%～9.9wt%.

17. according to the secondary cell of claim 15, at least a content that wherein is selected from described negative electrode active material in nickel, copper, zinc, gallium and the indium is 0.5wt%～14.9wt%.

18. according to the secondary cell of claim 11, wherein said negative electrode active material also comprises silver element.

19. according to the secondary cell of claim 18, wherein silver content is 0.1wt%～9.9wt% in described negative electrode active material.

20. according to the secondary cell of claim 11, wherein said negative electrode active material also comprises at least a element that is selected from aluminium, titanium, vanadium, chromium, niobium and the tantalum; Be selected from least a element in nickel, copper, zinc, gallium and the indium; And silver element.