CN101599557A - A kind of preparation method of polymer Li-ion battery - Google Patents
A kind of preparation method of polymer Li-ion battery Download PDFInfo
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- CN101599557A CN101599557A CNA2008101106192A CN200810110619A CN101599557A CN 101599557 A CN101599557 A CN 101599557A CN A2008101106192 A CNA2008101106192 A CN A2008101106192A CN 200810110619 A CN200810110619 A CN 200810110619A CN 101599557 A CN101599557 A CN 101599557A
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Abstract
The invention provides a kind of preparation method of polymer Li-ion battery, this method comprises the polymer Li-ion battery precursor is plastified, wherein, described plasticizing comprises carries out heating and cooling to the battery precursor, it is 30-60 ℃ that described heating makes the interior temperature of the housing of battery precursor, and under this heating-up temperature, placed 0.1-10 hour, it is 0 ℃ to-40 ℃ that described cooling makes the interior temperature of the housing of battery precursor, and places 0.1-10 hour under this chilling temperature.This method by the battery precursor is carried out heating and cooling, makes the plasticizing effect of polymer film better in plasticizing process, has improved the cycle performance and the security performance of the polymer Li-ion battery that obtains significantly.
Description
Technical field
The invention relates to a kind of preparation method of lithium ion battery, more precisely about a kind of preparation method of polymer Li-ion battery.
Background technology
Advantages such as lithium ion battery has that high working voltage, high-energy-density, volume are little, memory-less effect and life-span are long are that grow up after lead-acid battery, nickel-cadmium cell and Ni-MH battery a kind of has more highdensity novel high-energy battery.
At present, the liquid electrolyte system that is still that lithium ion battery adopts though adopt the lithium ion battery of liquid electrolyte system to have good high-rate charge-discharge capability and cryogenic property, exists potential safety hazards such as leakage.
Polymer Li-ion battery not only has the technological merit of liquid lithium ion battery, and has better security performance owing to leakage does not take place.
Polymer Li-ion battery mainly comprises positive plate, negative plate, barrier film, in gel electrolyte layer between anode pole piece and the barrier film and the gel electrolyte layer between negative plate and barrier film, wherein the preparation method of polymer Li-ion battery mainly is included in the certain density solution that contains polymer of surface-coated of battery positive/negative plate, again by phase transfer method with solvent extraction or distill, form the crosslinked polymer microporous film of one deck internal height on the pole piece surface, in battery, inject electrolyte then and make the polymer microporous film activation, form the layer of gel dielectric substrate.
For example, CN1700501A discloses a kind of phosphate polymer Li-ion battery and preparation method thereof, this method is carrier with the electrode slice, with the surface of polymer-coated in electrode slice, in temperature is that 50-110 ℃ and pressure are to make the polymer plasticizing under the condition of 400-4000kPa, form the stabilizing gel dielectric substrate, wherein, described polymer is the copolymer of vinylidene and hexafluoroethylene or is the homopolymers or the copolymer of oxirane, expoxy propane.The advantage of this method is polymer molecule and electrolyte solvent interaction of molecules, electrolyte is adsorbed in the polymer film, thereby make and do not have free liquid electrolyte in the entire cell, can avoid safety problems such as leakage, but the shortcoming of this method is: when plasticization temperature is higher than 60 ℃, described polymer film shrinks and closed pore, thereby blocking-up local ion path causes that the interface electric current distributes uneven cycle performance and the security performance that influences battery; And if the pressure of pressurized treatments control is improper, will oppress pole piece and pierce through barrier film, causes internal short-circuit, micropore that also can extruded polymer film makes polymer film absorption electrolyte ability drop simultaneously, causes leakage, thereby influences battery safety.
Summary of the invention
The object of the present invention is to provide a kind of preparation method who makes the polymer Li-ion battery that obtains have the polymer Li-ion battery of good cycle performance and security performance.
The invention provides a kind of preparation method of polymer Li-ion battery, this method comprises the polymer Li-ion battery precursor is plastified, wherein, described plasticizing comprises carries out heating and cooling to the battery precursor, it is 30-60 ℃ that described heating makes the interior temperature of the housing of battery precursor, and under this heating-up temperature, placed 0.1-10 hour, it is 0 ℃ to-40 ℃ that described cooling makes the interior temperature of the housing of battery precursor, and places 0.1-10 hour under this chilling temperature.
The present invention is by under 30-60 ℃ temperature the battery precursor being heated, and under such temperature, the ion path of described polymer film is unobstructed, interface electric current distributed uniform; And by under 0 to-40 ℃, the battery precursor being cooled off, strengthened combining between polymer film and the positive/negative plate, made the battery that obtains be difficult for the phenomenon of leakage takes place, thereby improved the cycle performance and the security performance of the polymer ions battery that obtains.For example, the discharge capacitance of the polymer Li-ion battery D1-D4 that embodiment 1-4 makes is up to more than 91.3%, and the acupuncture maximum temperature only is below 119.6 ℃, and the discharge capacity conservation rate of the reference polymer Li-ion battery that Comparative Examples 1 makes only is 81.5%, the acupuncture temperature then up to 324 ℃ and with smoldering and catch fire phenomenon, illustrates the cycle performance and the security performance that can improve the polymer Li-ion battery that obtains by method provided by the invention significantly.
Embodiment
The invention provides a kind of preparation method of polymer Li-ion battery, this method comprises the polymer Li-ion battery precursor is plastified, wherein, described plasticizing comprises carries out heating and cooling to the battery precursor, it is 30-60 ℃ that described heating makes the interior temperature of the housing of battery precursor, and under this heating-up temperature, placed 0.1-10 hour, it is 0 ℃ to-40 ℃ that described cooling makes the interior temperature of the housing of battery precursor, and places 0.1-10 hour under this chilling temperature.
According to the present invention, when the temperature in heating makes the housing of battery precursor was higher than 60 ℃, described polymer film shrank and closed pore, thereby blocking-up local ion path causes that the interface electric current distributes uneven cycle performance and the security performance that influences battery; When the temperature in heating makes the housing of battery precursor was lower than 30 ℃, the activity of polymer molecule reduced and the absorbent variation, can not fully adsorb electrolyte.When the temperature in cooling makes the housing of battery precursor is higher than 0 ℃, can't realize the effect of cooling off, cause between polymer film and the positive/negative plate combine relatively poor; When the temperature in cooling makes the housing of battery precursor was lower than-40 ℃, glass transition easily took place in polymer, formed noncrystally, and ionic mobility descends rapidly, and the solubility of lithium salts also descends simultaneously, causes lithium salts to be separated out, and causes battery performance to worsen.
In addition, as polymer Li-ion battery use LiPF
6During as electrolyte,, avoided LiPF because the heating-up temperature of plasticizing method of the present invention is 30-60 ℃
6Decomposition, thereby suppressed the generation of bad air, and then suppressed the expansion of battery, thereby the SEI film of protection negative terminal surface (phase film in the middle of the solid electrolyte) is not destroyed, and has improved cycle performance of battery and security performance.
Under the preferable case, it is 40-50 ℃ that described heating makes the interior temperature of the housing of battery precursor, and places 1-8 hour under this heating-up temperature, and described cooling makes the interior temperature of the housing of battery precursor be-10 ℃ to-40 ℃, and places 1-5 hour under this chilling temperature.
According to the present invention, under the preferable case, temperature is not more than 10 minutes from the time interval that heating-up temperature is reduced to chilling temperature in the housing of described battery precursor, more preferably 0.5-8 minute, when the time that heating-up temperature is reduced to chilling temperature is positioned at above-mentioned scope, combining between polymer film and the positive/negative plate be can strengthen more significantly, thereby the cycle performance and the security performance of polymer ions battery improved.
According to the present invention, described plasticizing process can carry out in each stage after the polymer Li-ion battery precursor injects electrolyte, for example, can plastify after injecting electrolyte, after changing into, plastify, plastify after sealing or battery is carried out plastifying behind the partial volume.
Method provided by the invention is applicable to various polymer Li-ion batteries, for example, and the polymer Li-ion battery that methods such as coiling, lamination prepare.
The polymer Li-ion battery that method provided by the invention obtains can be for square, cylindrical, and flexible package type polymer Li-ion battery.
Described polymer Li-ion battery precursor is conventionally known to one of skill in the art, and for example, described battery precursor can comprise: battery container and the pole piece and the nonaqueous electrolytic solution that are sealed in this battery container; Described pole piece comprises positive plate, negative plate, at the barrier film between positive plate and the negative plate, at the polymer film between positive plate and the barrier film, polymer film between negative plate and barrier film.
According to the present invention, the thickness of described polymer film can in very large range change, and under the preferable case, the thickness of described polymer film is the 1-25 micron.
The preparation method of described battery precursor is conventionally known to one of skill in the art.For example, this method can comprise: the positive plate and the negative plate of preparation battery; At the surface-coated polymer paste of positive plate and negative plate, form polymer film; Between positive plate and negative plate, barrier film is set, constitutes pole piece; This pole piece is contained in the battery container, injects electrolyte and encapsulation.
Described polymer paste contains polymer, solvent, plasticizer and inorganic filler; In the described polymer paste, the content of polymer, solvent, plasticizer and inorganic filler can in very large range change, under the preferable case, total weight with described polymer paste is a benchmark, the content of described polymer is 1-20 weight %, the content of described solvent is 50-90 weight %, and the content of described plasticizer is 1-30 weight %, and the content of described inorganic filler is 0.1-5 weight %.
Described polymer can be the polymer of the various routines that are used to prepare polymer Li-ion battery, for example, can be poly(ethylene oxide), PPOX, PEP-101, Kynoar, vinylidene fluoride-hexafluoropropylene copolymer, polyacrylonitrile, polyvinyl chloride, in polystyrene and the polyether sulfone one or more, the weight average molecular weight of described polymer can in very large range change, under the preferable case, the weight average molecular weight of described polymer is 100000-600000, the polymer that meets above-mentioned requirements can be commercially available, for example, the trade mark of ARKEMA company production is Kynoar-hexafluoropropylene copolymer of kynarflex.
Described solvent can be the solvent of the various routines that are used to prepare the polymer ions battery, for example, can be in acetone, butanone, cyclohexanone, methyl formate, ethyl acetate, methyl acetate, oxolane, 2-methyltetrahydrofuran, gamma-butyrolacton and the N-methyl pyrrolidone one or more.
Described inorganic filler can for example, can be Al for the inorganic filler of the various routines that are used to prepare polymer Li-ion battery
2O
3, SiO
2, ZrO
2, ZnO, TiO
2, BaTiO
3, LiTaO
3, Li
3N, γ-LiAlO
2, LiAg
4I
5And Li
3.95Mg
0.05SiO
4In one or more, the mean particle diameter of described inorganic filler can in very large range change, under the preferable case, the mean particle diameter of described inorganic filler is the 1-100 nanometer.
Described plasticizer can be the plasticizer of the various routines that are used to prepare polymer Li-ion battery, for example, described plasticizer can be repefral, dibutyl phthalate, dioctyl phthalate, toluene, dimethylbenzene, ethanol, isopropyl alcohol, n-butanol, isobutanol, cyclohexanol, ethylene glycol, 1, ammediol, 1, the 3-butanediol, one or more in pentane, n-hexane and the normal heptane.
The same with prior art, the preparation method of described positive plate is included on the positive electrode collector and applies the slurry that contains the conductive agent that positive active material, adhesive and selectivity contain, drying, and calendering promptly gets anodal after the cut-parts.Described drying usually under vacuum condition at 50-160 ℃, carry out under preferred 80-150 ℃.Described calendering and cut-parts are as well known to those skilled in the art, after calendering is finished, cut according to the anodal size of prepared battery request, obtain positive plate.
It is 0.1-30 milligram/square centimeter that described coating makes the coat side density of positive electrode on positive electrode collector, preferred 1-15 milligram/square centimeter.
Described positive electrode collector can be a various collector body known in those skilled in the art, as aluminium foil, Copper Foil etc., for example can be selected from aluminium foil.
Described positive electrode can be a various positive electrode known in those skilled in the art, generally include the conductive agent that positive active material, adhesive and selectivity contain, described positive active material can be selected from the positive active material of polymer Li-ion battery routine, as Li
xNi
1-yCoO
2(wherein, 0.9≤x≤1.1,0≤y≤1.0), Li
mMn
2-nB
nO
2(wherein, B is a transition metal, 0.9≤m≤1.1,0≤n≤1.0), Li
1+aM
bMn
2-bO
4(wherein ,-0.1≤a≤0.2,0≤b≤1.0, M is one or more in lithium, boron, magnesium, aluminium, titanium, chromium, iron, cobalt, nickel, copper, zinc, gallium, yttrium, fluorine, iodine, the element sulphur).
Positive electrode of the present invention has no particular limits adhesive, can adopt the various adhesive that can be used for polymer Li-ion battery known in the art, for example, can be live in the butadiene-styrene rubber one or more of Kynoar, polytetrafluoroethylene, the content of described adhesive is the 0.5-8 weight % of positive active material, is preferably 1-5 weight %.
Positive electrode provided by the invention can also optionally contain the common conductive agent that contains in the prior art positive electrode.Because conductive agent is used to increase the conductivity of electrode, reduce the internal resistance of battery, so the present invention preferably contains conductive agent.The content of described conductive agent and kind are conventionally known to one of skill in the art, for example, are benchmark with the positive electrode, and the content of conductive agent is generally 0-15 weight %, is preferably 0-10 weight %.Described conductive agent can be selected from one or more in other metal conductive agents such as conductive carbon black, acetylene black, electrically conductive graphite, carbon fiber, furnace black, nickel powder, copper powder.
The same with prior art, the preparation method of described negative plate is included on the negative electrode collector and applies the slurry that contains the conductive agent that negative electrode active material, adhesive and selectivity contain, drying, and calendering promptly gets negative plate after the cut-parts.Described drying usually under vacuum condition at 50-160 ℃, carry out under preferred 80-150 ℃.Described calendering and cut-parts are as well known to those skilled in the art, after calendering is finished, cut according to the negative pole size of prepared battery request, obtain negative plate.
It is 0.1-30 milligram/square centimeter that described coating makes the coat side density of negative material on negative electrode collector, preferred 1-15 milligram/square centimeter.
Described negative electrode collector is conventionally known to one of skill in the art, for example can be selected from aluminium foil, Copper Foil, nickel plated steel strip, the Punching steel strip one or more, and the present invention selects for use Copper Foil to make negative electrode collector.
Consisting of of described negative material is conventionally known to one of skill in the art, and it comprises negative electrode active material and adhesive.Described negative electrode active material can be selected from one or more in native graphite, Delanium, petroleum coke, organic cracking carbon, carbonaceous mesophase spherules, carbon fiber, ashbury metal, the silicon alloy.
The adhesive of described negative material can be selected from one or more in polyvinyl alcohol, polytetrafluoroethylene, CMC (CMC), the butadiene-styrene rubber (SBR).In general, the content of described adhesive is the 0.5-8 weight % of negative electrode active material, is preferably 1-5 weight %.
According to the present invention, the solvent that is used to prepare anode sizing agent and cathode size can be selected from conventional solvent, as being selected from N-methyl pyrrolidone (NMP), N, dinethylformamide (DMF), N, one or more in N-diethylformamide (DEF), methyl-sulfoxide (DMSO), oxolane (THF) and water and the alcohols.The consumption of solvent can be coated on the described collector body described slurry and gets final product.In general, the consumption of solvent is that to make the concentration of positive active material in the slurries be 40-90 weight %, is preferably 50-85 weight %.
Described barrier film has electrical insulation capability and liquid retainability energy, is arranged between positive pole and the negative pole, and is sealed in the battery case with positive pole, negative pole and electrolyte.Described barrier film can be the general various barrier films in this area, such as by those skilled in the art in the modified poly ethylene felt of respectively producing the trade mark, modified polypropene felt, ultra-fine fibre glass felt, vinylon felt or the nylon felt of known each manufacturer production and wettability microporous polyolefin film through welding or the bonding composite membrane that forms.
Described nonaqueous electrolytic solution is made up of nonaqueous solvents and the electrolyte that is dissolved in nonaqueous solvents.Above-mentioned nonaqueous solvents is not particularly limited, and can use known up to now nonaqueous solvents.Described nonaqueous solvents can be a various high boiling solvent of the prior art, low boiling point solvent or their mixture, for example can be selected from gamma-butyrolacton, vinyl carbonate, the ethyl-methyl carbonic ester, dimethyl carbonate, diethyl carbonate, carbonic acid first propyl ester, ethyl propyl carbonic acid ester, dipropyl carbonate, propene carbonate, vinylene carbonate, diphenyl carbonate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, dimethoxy-ethane, diethoxyethane, sultone, and other is fluorine-containing, sulfur-bearing or contain the ring-type organosilane ester of unsaturated bond, organic acid anhydride, the N-methyl pyrrolidone, the N-methylformamide, the N-methylacetamide, acetonitrile, N, dinethylformamide, sulfolane, in the methyl-sulfoxide one or more.
The electrolyte that dissolves in the described nonaqueous solvents, there is no particular limitation equally in the present invention, can use the electrolyte that is generally used for Lithium Secondary Battery Of Nonaqueous Electrolyte.As lithium hexafluoro phosphate (LiPF
6), LiBF4 (LiBF
4), hexafluoroarsenate lithium (LiSbF
6), lithium perchlorate (LiClO
4), fluorocarbon based sulfonic acid lithium (LiCF
3SO
3), Li (CF
3SO
2)
2N, LiC
4F
9SO
3, chlorine lithium aluminate (LiAlCl
4), LiN (C
xF
2x+1SO
2) (C
yF
2y+1SO
2) in (x and y are the natural number of 1-10 in the formula), lithium chloride (LiCl) and the lithium iodide (LiI) one or more.Electrolytical concentration is generally the 0.1-2.0 mol in the nonaqueous electrolytic solution, is preferably the 0.7-1.6 mol.The consumption of nonaqueous electrolytic solution can be 3-6 milligram/MAH.
It is pure that all kinds of solvents of the present invention and reagent are analysis.
The present invention is described further below in conjunction with embodiment.
Embodiment 1
Present embodiment is used to illustrate the preparation method of polymer Li-ion battery provided by the invention.
(1) preparation of polymer Li-ion battery precursor
1) preparation of positive plate
30 gram polyvinylidene fluoride (PVDF) are dissolved in about 500 gram N-methyl pyrrolidone (NMP) solvents make binder solution, the 940 gram LiCoO that will mix in advance then
2The acetylene black powder that serves as conductive agent with 30 grams joins in the above-mentioned solution, fully mixes and makes anode sizing agent; With tensile pulp machine this anode sizing agent is coated to thick 18 microns aluminium foil two sides equably, and to make coat side density be 23.5 milligrams/square centimeter.Through 125 ℃ of vacuum and heating dryings 1 hour, two rod milling train rolling formations, cut-parts make the positive pole of millimeter (wide) * 130,360 millimeters (length) * 43.5 micron (thick), contain the LiCoO of 5.25 grams of having an appointment on every positive pole
2
2) preparation of negative plate
Detect median particle diameter D through laser particle analyzer
50Be 15 microns native graphite (soddif commodity, DAG22) powder 960 grams, the Kynoar (PVDF) that serves as adhesive with 40 grams fully mixes, and is dissolved into about 500 grams and serves as in the N-methyl pyrrolidone of solvent, fully mixes and makes cathode size.With tensile pulp machine this cathode size is coated to the two sides that thickness is 10 microns the Copper Foil that serves as collector body equably, makes that the coat side density of negative material is 9.5 milligrams/square centimeter.Through 125 ℃ of vacuum and heating dryings 1 hour, two rod milling trains are calendaring molding under 1.0 MPa pressure, and the volume density that makes its negative material is 1.55 gram/cubic centimetres.Cut-parts make the negative pole of millimeter (wide) * 130,330 millimeters (length) * 44.5 micron (thick), contain 2.25 graphite that restrain on the every negative pole.
3) preparation of polymer film
With 8 parts by weight of polyvinylidene fluoride-hexafluoropropylene copolymer (ARKEMA company, Kynarflex-2801, weight average molecular weight is 470000), the N-methyl pyrrolidone of 65 weight portions, dibutyl phthalate (the Shanghai Ling Feng Fine Chemical Co., Ltd of 25 weight portions, AR) and the white carbon of 2 weight portions (Guangzhou Hua Lisen Science and Technology Ltd., SiO
2, mean particle diameter is 20 nanometers) mix, under 40 ℃, be mixed with polymer solution;
The polymer solution that obtains is coated in respectively on positive plate and the negative plate, and it is 5 microns that the amount of described coating makes the thickness of the polymer film that forms on the positive plate, and it is 5 microns that the amount of described coating makes the thickness of the polymer film that forms on the negative plate.
4) assembling of battery
To include in after positive pole, barrier film, negative pole lamination successively and the winding in 4.2 * 30 * 48 millimeters the square aluminum hull.
Lithium hexafluoro phosphate (the LiPF that will contain 1 mol
6) ethylene carbonate: the Methylethyl carbonic ester: diethyl carbonate (EC/EMC/DEC) volume ratio is 1: 1: 1 the about 2.6g of electrolyte, injects above-mentioned battery, obtains polymer Li-ion battery precursor A1.
(2) plasticizing of polymer Li-ion battery
Battery precursor A1 placed 35 ℃ drying box (Suzhou Hong Ruida company, H-VA-100N) heating in, making the interior temperature of housing of battery precursor A1 is 35 ℃ (TES1310 digital display thermometers), and under 35 ℃, placed 10 hours, change-40 ℃ the middle cooling of constant temperature and moisture test machine (KTHA-410CBS) afterwards immediately over to, in 10 minutes, make in the housing of battery precursor A1 temperature reduce to-40 ℃ (TES1310 digital display thermometers), and under-40 ℃, placed 0.5 hour, after taking out battery, make battery recovery to normal temperature, obtain polymer Li-ion battery D1.
Comparative Examples 1
Prepare polymer Li-ion battery according to the method identical with embodiment 1, difference is that the step that plastifies comprises that the battery that will obtain places 80 ℃ drying box (Suzhou Hong Ruida company, H-VA-100N) heating in, making the interior temperature of housing of battery precursor is 80 ℃ (TES1310 digital display thermometers), and under 80 ℃, placed 5 hours, and in heating, battery is applied the pressure of 1Mpa, behind the taking-up battery, make battery recovery to normal temperature, obtain reference polymer Li-ion battery CD1.
Embodiment 2
Present embodiment is used to illustrate the preparation method of polymer Li-ion battery provided by the invention.
(1) preparation of polymer Li-ion battery precursor
1) preparation of positive plate
30 gram polyvinylidene fluoride (PVDF) are dissolved in about 500 gram N-methyl pyrrolidone (NMP) solvents make binder solution, the 940 gram LiCoO that will mix in advance then
2The acetylene black powder that serves as conductive agent with 30 grams joins in the above-mentioned solution, fully mixes and makes anode sizing agent; With tensile pulp machine this anode sizing agent is coated to thick 18 microns aluminium foil two sides equably, and to make coat side density be 23.5 milligrams/square centimeter.Through 125 ℃ of vacuum and heating dryings 1 hour, two rod milling train rolling formations, cut-parts make the positive pole of millimeter (wide) * 130,360 millimeters (length) * 43.5 micron (thick), contain the LiCoO of 5.25 grams of having an appointment on every positive pole
2
2) preparation of negative plate
Detect median particle diameter D through laser particle analyzer
50Be 15 microns native graphite (soddif commodity, DAG22) powder 960 grams, the Kynoar (PVDF) that serves as adhesive with 40 grams fully mixes, and is dissolved into about 500 grams and serves as in the N-methyl pyrrolidone of solvent, fully mixes and makes cathode size.With tensile pulp machine this cathode size is coated to the two sides that thickness is 10 microns the Copper Foil that serves as collector body equably, makes that the coat side density of negative material is 9.5 milligrams/square centimeter.Through 125 ℃ of vacuum and heating dryings 1 hour, two rod milling trains are calendaring molding under 1.0 MPa pressure, and the volume density that makes its negative material is 1.55 gram/cubic centimetres.Cut-parts make the negative pole of millimeter (wide) * 130,330 millimeters (length) * 44.5 micron (thick), contain 2.25 graphite that restrain on the every negative pole.
3) preparation of polymer film
With the N-methyl pyrrolidone of the polyacrylonitrile (Jinan Kang Nuo chemical industry Co., Ltd, weight average molecular weight 350000) of 15 weight portions, 80 weight portions, the repefral of 3 weight portions (Shanghai Ling Feng Fine Chemical Co., Ltd, AR) and the Al of 2 weight portions
2O
3(Shanghai Gao Na powder technology Co., Ltd, NP-A-10, mean particle diameter are 90 nanometers) mixes, and is mixed with polymer solution under 40 ℃;
The polymer solution that obtains is coated in respectively on positive plate and the negative plate, and it is 20 microns that the amount of described coating makes the thickness of the polymer film that forms on the positive plate, and it is 20 microns that the amount of described coating makes the thickness of the polymer film that forms on the negative plate.
4) assembling of battery
To include in after positive pole, barrier film, negative pole lamination successively and the winding in 4.2 * 30 * 48 millimeters the square aluminum hull.
Lithium hexafluoro phosphate (the LiPF that will contain 1 mol
6) ethylene carbonate: the Methylethyl carbonic ester: diethyl carbonate (EC/EMC/DEC) volume ratio is 1: 1: 1 the about 2.6g of electrolyte, injects above-mentioned battery, obtains polymer Li-ion battery precursor A2.
(2) plasticizing of polymer Li-ion battery
Battery precursor A2 placed 55 ℃ drying box (Suzhou Hong Ruida company, H-VA-100N) heating in, making the interior temperature of housing of battery precursor A1 is 55 ℃ (TES1310 digital display thermometers), and under 55 ℃, placed 5 hours, change-5 ℃ the middle cooling of constant temperature and moisture test machine (KTHA-410CBS) afterwards immediately over to, make in 1 minute that temperature is-5 ℃ (TES1310 digital display thermometer) in the housing of battery precursor A2, and under-5 ℃, placed 8 hours, after taking out battery, make battery recovery to normal temperature, obtain polymer Li-ion battery D2.
Embodiment 3
Present embodiment is used to illustrate the preparation method of polymer Li-ion battery provided by the invention.
(1) preparation of polymer Li-ion battery precursor
1) preparation of positive plate
30 gram polyvinylidene fluoride (PVDF) are dissolved in about 500 gram N-methyl pyrrolidone (NMP) solvents make binder solution, the 940 gram LiCoO that will mix in advance then
2The acetylene black powder that serves as conductive agent with 30 grams joins in the above-mentioned solution, fully mixes and makes anode sizing agent; With tensile pulp machine this anode sizing agent is coated to thick 18 microns aluminium foil two sides equably, and to make coat side density be 23.5 milligrams/square centimeter.Through 125 ℃ of vacuum and heating dryings 1 hour, two rod milling train rolling formations, cut-parts make the positive pole of millimeter (wide) * 130,360 millimeters (length) * 43.5 micron (thick), contain the LiCoO of 5.25 grams of having an appointment on every positive pole
2
2) preparation of negative plate
Detect median particle diameter D through laser particle analyzer
50Be 15 microns native graphite (soddif commodity, DAG22) powder 960 grams, the Kynoar (PVDF) that serves as adhesive with 40 grams fully mixes, and is dissolved into about 500 grams and serves as in the N-methyl pyrrolidone of solvent, fully mixes and makes cathode size.With tensile pulp machine this cathode size is coated to the two sides that thickness is 10 microns the Copper Foil that serves as collector body equably, makes that the coat side density of negative material is 9.5 milligrams/square centimeter.Through 125 ℃ of vacuum and heating dryings 1 hour, two rod milling trains are calendaring molding under 1.0 MPa pressure, and the volume density that makes its negative material is 1.55 gram/cubic centimetres.Cut-parts make the negative pole of millimeter (wide) * 130,330 millimeters (length) * 44.5 micron (thick), contain 2.25 graphite that restrain on the every negative pole.
3) preparation of polymer film
With 6 parts by weight of polyvinylidene fluoride (Wu Yu chemistry, PVDF7200, weight average molecular weight 420000), the dioctyl phthalate of the oxolane of 60 weight portions, 20 weight portions (Shanghai Ling Feng Fine Chemical Co., Ltd, AR), the normal heptane of 10 weight portions and the Al of 4 weight portions
2O
3(Shanghai Gao Na powder technology Co., Ltd, NP-A-10, mean particle diameter are 50 nanometers) mixes, and is mixed with polymer solution under 40 ℃;
The polymer solution that obtains is coated in respectively on positive plate and the negative plate, and it is 10 microns that the amount of described coating makes the thickness of the polymer film that forms on the positive plate, and it is 10 microns that the amount of described coating makes the thickness of the polymer film that forms on the negative plate.
4) assembling of battery
To include in after positive pole, barrier film, negative pole lamination successively and the winding in 4.2 * 30 * 48 millimeters the square aluminum hull.
Lithium hexafluoro phosphate (the LiPF that will contain 1 mol
6) ethylene carbonate: the Methylethyl carbonic ester: diethyl carbonate (EC/EMC/DEC) volume ratio is 1: 1: 1 the about 2.6g of electrolyte, injects above-mentioned battery, obtains polymer Li-ion battery precursor A3.
(2) plasticizing of polymer Li-ion battery
Battery precursor A3 placed 50 ℃ drying box (Suzhou Hong Ruida company, H-VA-100N) heating in, making the interior temperature of housing of battery precursor A3 is 50 ℃ (TES1310 digital display thermometers), and under 50 ℃, placed 8 hours, change-10 ℃ the middle cooling of constant temperature and moisture test machine (KTHA-410CBS) afterwards immediately over to, make in 5 minutes that temperature is-10 ℃ (TES1310 digital display thermometer) in the housing of battery precursor A3, and under-10 ℃, placed 5 hours, after taking out battery, make battery recovery to normal temperature, obtain polymer Li-ion battery D3.
Embodiment 4
Present embodiment is used to illustrate the preparation method of polymer Li-ion battery provided by the invention.
(1) preparation of polymer Li-ion battery precursor
1) preparation of positive plate
30 gram polyvinylidene fluoride (PVDF) are dissolved in about 500 gram N-methyl pyrrolidone (NMP) solvents make binder solution, the 940 gram LiCoO that will mix in advance then
2The acetylene black powder that serves as conductive agent with 30 grams joins in the above-mentioned solution, fully mixes and makes anode sizing agent; With tensile pulp machine this anode sizing agent is coated to thick 18 microns aluminium foil two sides equably, and to make coat side density be 23.5 milligrams/square centimeter.Through 125 ℃ of vacuum and heating dryings 1 hour, two rod milling train rolling formations, cut-parts make the positive pole of millimeter (wide) * 130,360 millimeters (length) * 43.5 micron (thick), contain the LiCoO of 5.25 grams of having an appointment on every positive pole
2
2) preparation of negative plate
Detect median particle diameter D through laser particle analyzer
50Be 15 microns native graphite (soddif commodity, DAG22) powder 960 grams, the Kynoar (PVDF) that serves as adhesive with 40 grams fully mixes, and is dissolved into about 500 grams and serves as in the N-methyl pyrrolidone of solvent, fully mixes and makes cathode size.With tensile pulp machine this cathode size is coated to the two sides that thickness is 10 microns the Copper Foil that serves as collector body equably, makes that the coat side density of negative material is 9.5 milligrams/square centimeter.Through 125 ℃ of vacuum and heating dryings 1 hour, two rod milling trains are calendaring molding under 1.0 MPa pressure, and the volume density that makes its negative material is 1.55 gram/cubic centimetres.Cut-parts make the negative pole of millimeter (wide) * 130,330 millimeters (length) * 44.5 micron (thick), contain 2.25 graphite that restrain on the every negative pole.
3) preparation of polymer film
With 10 parts by weight of polyvinylidene fluoride-hexafluoropropylene (ARKEMA company, Kynar 761, weight average molecular weight 370000), the repefral of the N-methyl pyrrolidone of 70 weight portions, 28 weight portions (Shanghai Ling Feng Fine Chemical Co., Ltd, AR) and the Al of 2 weight portions
2O
3(Shanghai Gao Na powder technology Co., Ltd, NP-A-10, mean particle diameter are 20) mixes, and is mixed with polymer solution under 40 ℃;
The polymer solution that obtains is coated in respectively on positive plate and the negative plate, and it is 10 microns that the amount of described coating makes the thickness of the polymer film that forms on the positive plate, and it is 10 microns that the amount of described coating makes the thickness of the polymer film that forms on the negative plate.
4) assembling of battery
To include in after positive pole, barrier film, negative pole lamination successively and the winding in 4.2 * 30 * 48 millimeters the square aluminum hull.
To contain 1 mole lithium hexafluoro phosphate (LiPF
6) ethylene carbonate: the Methylethyl carbonic ester: diethyl carbonate (EC/EMC/DEC) volume ratio is 1: 1: 1 the about 2.6g of electrolyte, injects above-mentioned battery, obtains polymer Li-ion battery precursor A3.
(2) plasticizing of polymer Li-ion battery
Battery precursor A4 placed 40 ℃ drying box (Suzhou Hong Ruida company, H-VA-100N) heating in, making the interior temperature of housing of battery precursor A4 is 40 ℃ (TES1310 digital display thermometers), and under 40 ℃, placed 3 hours, change-30 ℃ the middle cooling of constant temperature and moisture test machine (KTHA-410CBS) afterwards immediately over to, make in 8 minutes that temperature is-30 ℃ (TES1310 digital display thermometer) in the housing of battery precursor A4, and under-30 ℃, placed 1 hour, after taking out battery, make battery recovery to normal temperature, obtain polymer Li-ion battery D4.
Embodiment 5
The polymer Li-ion battery D1 that respectively embodiment 1 is obtained carries out cycle performance test and lancing test in accordance with the following methods:
The cycle performance test
Under 25 ℃, with the constant current of 700mA above-mentioned battery is carried out constant current charge, charging rises to 4.2V at voltage and carries out constant voltage charge later on, by electric current 25mA by voltage 4.2V; Shelved 10 minutes, and to 3.0V, used BS-9300R secondary cell device for detecting performance to measure the initial discharge capacity that obtains battery with the current discharge of 700mA.After shelving 10 minutes, repeat above step, make continuous charge-discharge test, obtain the discharge battery capacity after battery circulates for 300 times, calculate the discharge capacitance of 300 circulation back batteries according to following formula.The result is as shown in table 1.
Discharge capacitance=300 time circulation back discharge capacity/initial discharge capacity * 100%
Lancing test
Under 25 ℃, with battery with the 1C current charges to 4.2V, stop electric current 100mA, in safety cage, pierce through battery with the speed of 5mm/s then with the iron nail of φ=2.5mm, temperature with the battery surface of TES1310 digital display thermometer record after one minute, when the temperature of battery surface is reduced to below 40 ℃, battery is blasted or on fire after finish experiment, thereby obtain the maximum temperature of battery surface, and the variation of observation battery outward appearance.The result is as shown in table 2.
Comparative Examples 2
Compare cycle performance test and the lancing test of the reference polymer Li-ion battery CD1 that example 1 obtains according to the method identical with embodiment 5, the result respectively as shown in Table 1 and Table 2.
Embodiment 6-8
The polymer Li-ion battery D2-D4 that embodiment 2-4 is obtained according to the method identical with embodiment 5 carries out cycle performance test and lancing test, and the result respectively as shown in Table 1 and Table 2.
Table 1
As can be seen from Table 1, the discharge capacitance of the polymer Li-ion battery D1-D4 that method provided by the invention makes is up to more than 91.3%, and the discharge capacity conservation rate of the reference polymer Li-ion battery CD1 that Comparative Examples 1 makes only is 81.5%, and the cycle performance that can improve the polymer Li-ion battery that obtains by method provided by the invention significantly is described.
Table 2
| The embodiment numbering | Initial voltage (V) | Initial temperature (℃) | Maximum temperature (℃) | Initial internal resistance (m Ω) | Original depth (mm) | Phenomenon | The result |
| Embodiment 5 | 4.14 | 29.1 | 118.5 | 41.5 | 4.05 | N | By |
| Embodiment 6 | 4.15 | 29.8 | 119.6 | 42.1 | 4.07 | N | By |
| Embodiment 7 | 4.15 | 29.5 | 117.4 | 41.8 | 4.08 | N | By |
| Embodiment 8 | 4.14 | 29.4 | 116.7 | 41.6 | 4.02 | N | By |
| Comparative Examples 2 | 4.14 | 29.9 | 324.5 | 42.7 | 4.02 | SM+F | Failure |
Annotate: N: the battery distortion, but do not smolder
SM: the battery distortion, and with the phenomenon of smoldering
F: the battery distortion, and with smoldering and catching fire phenomenon
As can be seen from Table 2, the polymer Li-ion battery D1-D4 acupuncture maximum temperature that makes by method provided by the invention only is below 119.6 ℃, the acupuncture maximum temperature of the reference polymer Li-ion battery CD1 that Comparative Examples 1 makes then up to 324 ℃ and with smoldering and catch fire phenomenon, illustrates the security performance that can improve the polymer Li-ion battery that obtains by method provided by the invention significantly.
Claims (10)
1, a kind of preparation method of polymer Li-ion battery, this method comprises the polymer Li-ion battery precursor is plastified, it is characterized in that, described plasticizing comprises carries out heating and cooling to the battery precursor, it is 30-60 ℃ that described heating makes the interior temperature of the housing of battery precursor, and under this heating-up temperature, placed 0.1-10 hour, it is 0 ℃ to-40 ℃ that described cooling makes the interior temperature of the housing of battery precursor, and places 0.1-10 hour under this chilling temperature.
2, method according to claim 1, wherein, it is 40-50 ℃ that described heating makes the interior temperature of the housing of battery precursor, and places 1-8 hour under this heating-up temperature, described cooling makes the interior temperature of the housing of battery precursor be-10 ℃ to-40 ℃, and places 1-5 hour under this chilling temperature.
3, method according to claim 1 and 2, wherein, temperature is not more than 10 minutes from the time interval that heating-up temperature is reduced to chilling temperature in the housing of described battery precursor.
4, method according to claim 1, wherein, described battery precursor comprises: battery container and the pole piece and the nonaqueous electrolytic solution that are sealed in this battery container; Described pole piece comprises positive plate, negative plate, at the barrier film between positive plate and the negative plate, at the polymer film between positive plate and the barrier film, polymer film between negative plate and barrier film.
5, method according to claim 4, wherein, the thickness of described polymer film is the 1-25 micron.
6, method according to claim 4, wherein, the preparation method of described battery precursor comprises: the positive plate and the negative plate of preparation battery; At the surface-coated polymer paste of positive plate and negative plate, form polymer film; Between positive plate and negative plate, barrier film is set, constitutes pole piece; This pole piece is contained in the battery container, injects electrolyte and encapsulation.
7, method according to claim 6, wherein, described polymer paste comprises polymer, solvent, plasticizer and inorganic filler, total weight with described polymer paste is a benchmark, the content of described polymer is 1-20 weight %, the content of described solvent is 50-90 weight %, and the content of described plasticizer is 1-30 weight %, and the content of described inorganic filler is 0.1-5 weight %.
8, method according to claim 7, wherein, described polymer is one or more in poly(ethylene oxide), PPOX, PEP-101, Kynoar, vinylidene fluoride-hexafluoropropylene copolymer, polyacrylonitrile and the polyether sulfone, and the weight average molecular weight of described polymer is 100000-600000.
9, method according to claim 7, wherein, described solvent is one or more in acetone, butanone, cyclohexanone, methyl formate, ethyl acetate, methyl acetate, oxolane, 2-methyltetrahydrofuran, gamma-butyrolacton and the N-methyl pyrrolidone; Described inorganic filler is Al
2O
3, SiO
2, ZrO
2, ZnO, TiO
2, BaTiO
3, LiTaO
3, Li
3N, γ-LiAlO
2, LiAg
4I
5And Li
3.95Mg
0.05SiO
4In one or more, the mean particle diameter of described inorganic filler is the 1-100 nanometer.
10, method according to claim 7, wherein, described plasticizer is repefral, dibutyl phthalate, dioctyl phthalate, toluene, dimethylbenzene, ethanol, isopropyl alcohol, n-butanol, isobutanol, cyclohexanol, ethylene glycol, 1, ammediol, 1, the 3-butanediol, one or more in pentane, n-hexane and the normal heptane.
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| CN103151563A (en) * | 2012-06-27 | 2013-06-12 | 深圳市海太阳实业有限公司 | Polymer cell and preparation method thereof |
| CN104718657A (en) * | 2012-11-21 | 2015-06-17 | 株式会社Lg化学 | Lithium secondary battery |
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| JP2002110241A (en) * | 2000-09-29 | 2002-04-12 | Sharp Corp | Lithium polymer secondary battery and its production method |
| CN1152086C (en) * | 2001-05-25 | 2004-06-02 | 复旦大学 | Process for preparing gel-state lithium ion polymer as electrolyte and bettery |
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| CN103151563A (en) * | 2012-06-27 | 2013-06-12 | 深圳市海太阳实业有限公司 | Polymer cell and preparation method thereof |
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| US9660266B2 (en) | 2012-11-21 | 2017-05-23 | Lg Chem, Ltd. | Lithium secondary battery |
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