CN109786657B - Current collector, current collector manufacturing method, electrode pole piece and lithium ion battery - Google Patents
Current collector, current collector manufacturing method, electrode pole piece and lithium ion battery Download PDFInfo
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Images
Classifications
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
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- Cell Electrode Carriers And Collectors (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention relates to a current collector, a current collector manufacturing method, an electrode plate and a lithium ion battery, wherein the current collector comprises: the metal foil comprises two opposite surfaces, at least one of the two surfaces is provided with an oxidized region, the oxidized region accounts for 20-60% of the total area of the two surfaces, and the surface resistance of the metal foil is 3 omega/cm2～10Ω/cm2(ii) a And an undercoat layer formed on the metal foil. The current collector, the current collector manufacturing method, the electrode plate and the lithium ion battery provided by the invention can effectively and stably inhibit the thermal runaway of a battery cell, improve the safety of the lithium ion battery and simultaneously have good electrical properties.
Description
Technical Field
The invention belongs to the technical field of batteries, and particularly relates to a current collector, a current collector manufacturing method, an electrode plate and a lithium ion battery.
Background
With the widespread application of lithium ion batteries, the safety performance of the lithium ion batteries is one of the performances which are very concerned by consumers and is also a very difficult problem to solve. At present, a new process adopted in the aspect of safety performance of a lithium ion battery is to protect a current collector by adopting a bottom coating, and meanwhile, the short-circuit resistance can be increased, the short-circuit power can be reduced, and thermal runaway can be inhibited, so that the safety performance of the lithium ion battery can be improved.
However, the above-mentioned technical solution of disposing the undercoat layer between the current collector and the active material layer only reduces the probability of causing a short circuit inside the lithium ion battery when being squeezed, impacted, or pierced by a sharp object, and still has a risk of causing thermal runaway of the battery cell.
Disclosure of Invention
The embodiment of the invention provides a current collector, an electrode pole piece, a lithium ion battery and a manufacturing method thereof, which can increase the short-circuit resistance of a battery cell, reduce the short-circuit power, improve the short-circuit heating of the battery cell, effectively and stably inhibit the thermal runaway of the battery cell, improve the safety of the lithium ion battery and simultaneously have good electrical properties.
An aspect of an embodiment of the present invention provides a current collector, including: the metal foil comprises two opposite surfaces, at least one of the two surfaces is provided with an oxidized region, the oxidized region accounts for 20-60% of the total area of the two surfaces, and the surface resistance of the metal foil is 3 omega/cm2～10Ω/cm2(ii) a And an undercoat layer formed on the metal foil.
According to the current collector provided by the embodiment of the invention, the surface resistance of the current collector is increased by performing local oxidation treatment on the surface of the metal foil, and in the battery cell manufactured by using the current collector, the short-circuit resistance of the metal foil in contact with the opposite electrode is increased, the short-circuit power is reduced, the short-circuit heating of the battery cell is improved, and the heat generation is remarkably reduced, so that the thermal runaway of the battery cell is effectively and stably inhibited, and 100% of the battery cell passes through a nail penetration test.
According to the current collector provided by the embodiment of the invention, after the surface of the metal foil is subjected to local oxidation treatment, the surface of the metal foil is further coated with the base coating material, so that the current collector has firm bonding force on the metal foil, and can prevent the metal foil from falling off, thereby protecting the metal foil, avoiding the direct contact between the metal foil and an opposite electrode when in nail piercing, further increasing the short-circuit resistance of the battery cell while protecting the metal foil, reducing the short-circuit power, and improving the short-circuit heating of the battery cell.
The current collector provided by the embodiment of the invention has good electrical properties while improving the safety of the lithium ion battery.
According to one aspect of an embodiment of the present invention, a metal foil includes opposing first and second surfaces; the first surface is provided with an oxidation area, and the oxidation area accounts for 40-60% of the total area of the first surface; and/or the second surface has an oxidized region, the oxidized region comprising 40% to 60% of the total area of the second surface.
According to an aspect of the embodiment of the present invention, the metal foil includes first and second opposite surfaces, the first and/or second surfaces are divided into first and second regions in a width direction thereof, the first and second regions are alternately distributed in the width direction, and the first region is the oxidized region.
According to an aspect of the embodiment of the present invention, the first region has a bar shape, a polygonal shape, a circular shape, or a nearly circular shape.
According to an aspect of the embodiment of the present invention, each of the first region and the second region has a strip shape and extends in a length direction of the metal foil; the middle position of the first surface and/or the second surface in the width direction is a first area, and second areas are distributed on two sides of the first area; alternatively, the first surface and/or the second surface include three first regions and two second regions alternately distributed with each other in a width direction thereof.
According to an aspect of the embodiment of the present invention, the metal foil is an aluminum foil, and the aluminum foil in the oxidation region is oxidized to form a hydrated oxide film; the undercoat layer is formed at least in the first region.
According to the current collector provided by the embodiment of the invention, the oxidation area of the aluminum foil forms the hydrated oxide film, on one hand, the surface of the hydrated oxide film is rough, the roughness is 0.2-1 μm, and the adhesive force between the aluminum foil and the bottom coating can be enhanced; on the other hand, the hydrated oxide film is a porous structure, closed pores can be generated when the hydrated oxide film is heated, namely under the condition of temperature rise, water molecules in the hydrated oxide film quickly permeate into micropores, because the local pH value is quite high, hydroxide radicals meet aluminum ions diffused outwards in the micropores to form hydrated alumina precipitates, the hydrated alumina can be incompletely crystallized pseudo-boehmite (pseudo-boehmite), solid product precipitates are increased continuously through dissolution-precipitation reaction, the precipitates are developed from the pore walls and the pore bottoms to block the whole micropores, and the electric transmission between the active material layer and the aluminum foil is blocked, so that the occurrence of thermal runaway is effectively prevented; on the other hand, the hydrated oxide film has larger resistance, can increase the short-circuit resistance in the short-circuit process and reduce the heat generation of short circuit; on the other hand, the hydrated oxide film has uniformly distributed defects on the surface, and generates some dangling bonds, thereby facilitating the contact of the bottom coating and the aluminum foil, improving the electrical property and improving the cycle performance of the battery.
Another aspect of an embodiment of the present invention provides a method of manufacturing a current collector, including:
covering a protective film on the partial surface of the metal foil, placing the metal foil in pure water at the temperature of 70-100 ℃, or in ammonia water at the temperature of 60-80 ℃, an amine aqueous solution or a mixed solution of ammonia water and amine, and treating for 3600-7200 s; wherein the concentration of the ammonia water is 0.5-1 mol/L; the concentration of the amine aqueous solution is 0.5 mol/L-1 mol/L; in the mixed solution of ammonia water and amine, the total concentration of ammonia and amine is 0.5-1 mol/L, and the mass ratio of ammonia to amine is 1: 5-5: 1;
carrying out heat treatment on the treated metal foil at the temperature of 300-500 ℃ for 6-8 h to generate a hydrated oxide film on the surface of the metal foil;
and tearing off the protective film covered on the metal foil, coating the base coating material on the metal foil, and drying to form the base coating.
The manufacturing method of the current collector provided by the embodiment of the invention is simple and has strong manufacturability.
According to another aspect of an embodiment of the invention, the amine is monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, propylenediamine, diisopropylamine or aniline.
In another aspect, the present invention provides an electrode sheet, which includes a current collector and an active material layer, which are sequentially stacked, wherein the current collector is the current collector provided above.
In another aspect, the present invention provides a lithium ion battery, which includes a cathode plate, an anode plate, a separator, and an electrolyte. The cathode pole piece and/or the anode pole piece are/is the electrode pole pieces.
The lithium ion battery provided by the embodiment of the invention has excellent electrical property and higher safety performance.
Drawings
Features, advantages and technical effects of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.
Fig. 1 is a schematic structural diagram of a current collector provided in an embodiment of the present invention.
Fig. 2 is a schematic structural diagram of an electrode sheet according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantageous technical effects of the present invention more clear, the present invention is further described in detail with reference to the following embodiments. It should be understood that the examples described in this specification are for the purpose of illustration only and are not intended to limit the invention, and the formulation, proportions, etc. of the examples may be selected appropriately without materially affecting the results.
For the sake of brevity, only some numerical ranges are explicitly disclosed herein. However, any lower limit may be combined with any upper limit to form ranges not explicitly recited; and any lower limit may be combined with any other lower limit to form a range not explicitly recited, and similarly any upper limit may be combined with any other upper limit to form a range not explicitly recited. Also, although not explicitly recited, each point or individual value between endpoints of a range is encompassed within the range. Thus, each point or individual value can form a range not explicitly recited as its own lower or upper limit in combination with any other point or individual value or in combination with other lower or upper limits.
In the description herein, it is noted that, unless otherwise specified, "a plurality" means one or more than one; "plurality" means two or more; the terms "first" and "second" are used for convenience only and should not be construed as limiting the present invention; the terms "upper", "lower", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present disclosure.
In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the present invention can be understood as appropriate to those of ordinary skill in the art.
The above summary of the present invention is not intended to describe each disclosed embodiment or every implementation of the present invention. The following description more particularly exemplifies illustrative embodiments. At various points throughout this application, guidance is provided through a list of embodiments that can be used in various combinations. In each instance, the list is merely a representative group and should not be construed as exhaustive.
Current collector
Referring to fig. 1, according to a first aspect of an embodiment of the present invention, there is provided a current collector, including: a metal foil 1 comprising a first surface 11 and a second surface 12 opposite to each other, the first surface 11 having an oxidized region, wherein the oxidized region occupies 40% to 60%, preferably 43% to 56%, of the total area of the first surface 11, and the metal foil 1 has a surface resistance of 3 Ω/cm2～10Ω/cm2Preferably 3. omega./cm2～5Ω/cm2(ii) a And an undercoat layer 2 formed on the first surface 11 of the metal foil 1 and covering the oxidized region and the non-oxidized region.
Specifically, as an example, the metal foil 1 has a predetermined length and width, and the longitudinal direction of the metal foil 1 is a direction in which the electrode sheet manufactured using the same is rolled to form a cell. As shown in fig. 1, the first surface 11 of the metal foil 1 includes a first region 111 and two second regions 112 in the width direction X, and in the width direction X, the first region 111 is located at the center of the first surface 11 of the metal foil 1, the two second regions 112 are distributed at two sides of the first region 111, and both the first region 111 and the second region 112 are strip-shaped and extend along the length direction of the metal foil 1, wherein the first region 111 is an oxidized region, and the second region 112 is a non-oxidized region. The first region 111, i.e. the oxidized region, accounts for 40% to 60%, preferably 43% to 56%, of the total area of the first surface 11 of the metal foil 1. The primer layer 2 is located on the first surface 11 of the metal foil 1 and covers the first area 111 and the second area 112. The primer layer 2 contains a conductive agent and a binder, and can be firmly bonded to the metal foil 1. It is to be understood that the undercoat layer may also be selectively formed on the metal foil at positions corresponding to the first regions.
It is understood that, in the width direction X, the current collector may also be arranged: the metal foil comprises three first areas and two second areas which are alternately distributed, wherein the first areas are oxidized areas, and the second areas are non-oxidized areas. The first area is in a shape of strip, polygon, circle or approximate circle.
According to the current collector provided by the embodiment of the invention, the surface resistance of the current collector is increased by performing local oxidation treatment on the surface of the metal foil, in the battery core manufactured by using the current collector, the short-circuit resistance of the metal foil in contact with the opposite electrode of the metal foil is increased, the short-circuit power is reduced, the short-circuit heating of the battery core is improved, the heat generation is obviously reduced, and the surface resistance of the metal foil is controlled within a preset range by controlling the width and the oxidation degree of an oxidation area, so that the thermal runaway of the battery core is effectively and stably inhibited, and 100% of the current collector passes through.
According to the current collector provided by the embodiment of the invention, after the surface of the metal foil is subjected to local oxidation treatment, the surface of the metal foil is further coated with the base coating material, so that the current collector has firm bonding force on the metal foil, and can prevent the metal foil from falling off, thereby protecting the metal foil, avoiding the direct contact between the metal foil and an opposite electrode when in nail piercing, further increasing the short-circuit resistance of the battery cell while protecting the metal foil, reducing the short-circuit power, and improving the short-circuit heating of the battery cell.
The current collector provided by the embodiment of the invention has good electrical properties while improving the safety of the lithium ion battery.
In some alternative embodiments, the metal foil is aluminum foil, and the aluminum foil in the oxidized region is oxidized to form a hydrated oxide film.
According to the current collector provided by the embodiment of the invention, the oxidation area of the aluminum foil forms the hydrated oxide film, on one hand, the surface of the hydrated oxide film is rough, the roughness is 0.2-1 μm, and the adhesive force between the aluminum foil and the bottom coating can be enhanced; on the other hand, the hydrated oxide film is a porous structure, closed pores can be generated when the hydrated oxide film is heated, namely under the condition of temperature rise, water molecules in the hydrated oxide film quickly permeate into micropores, because the local pH value is quite high, hydroxide radicals meet aluminum ions diffused outwards in the micropores to form hydrated alumina precipitates, the hydrated alumina can be incompletely crystallized pseudo-boehmite (pseudo-boehmite), solid product precipitates are increased continuously through dissolution-precipitation reaction, the precipitates are developed from the pore walls and the pore bottoms to block the whole micropores, and the electric transmission between the active material layer and the aluminum foil is blocked, so that the occurrence of thermal runaway is effectively prevented; on the other hand, the hydrated oxide film has larger resistance, can increase the short-circuit resistance in the short-circuit process and reduce the heat generation of short circuit; on the other hand, the hydrated oxide film has uniformly distributed defects on the surface, and generates some dangling bonds, thereby facilitating the contact of the bottom coating and the aluminum foil, improving the electrical property and improving the cycle performance of the battery.
Method for manufacturing current collector
According to a second aspect of an embodiment of the present invention, there is provided a method of manufacturing a current collector, including the steps of: s1, covering a protective film on the partial surface of the metal foil, placing the metal foil in pure water at the temperature of 70-100 ℃, or in ammonia water at the temperature of 60-80 ℃, an amine aqueous solution or a mixed solution of ammonia water and amine, and treating for 3600-7200S; wherein the concentration of the ammonia water is 0.5-1 mol/L; the concentration of the amine aqueous solution is 0.5-1 mol/L; in the mixed solution of the ammonia water and the amine, the total concentration of the ammonia and the amine is 0.5-1 mol/L, and the mass ratio of the ammonia to the amine is 1: 5-5: 1; the amine comprises monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, propylenediamine, diisopropylamine or aniline; s2, carrying out heat treatment on the treated metal foil for 6 to 8 hours in a drying environment at the temperature of between 300 and 500 ℃, and generating a hydrated oxide film with uniformly distributed defects in an area which is not covered with a protective film on the surface of the metal foil; and S3, tearing off the protective film covered on the metal foil, coating the base coating material on the metal foil, covering the oxidized area and the non-oxidized area, and drying to form the base coating to obtain the current collector.
Electrode pole piece
Referring to fig. 2, according to a third aspect of the embodiments of the present invention, there is provided an electrode tab including a current collector and an active material layer, which are sequentially stacked, wherein the current collector includes: a metal foil 1 ofThe metal foil 1 comprises a first surface 11 and a second surface 12 which are opposite, the first surface 11 is provided with an oxidized area which accounts for 40-60%, preferably 43-56% of the total area of the first surface, and the surface resistance of the metal foil is 3 omega/cm2～10Ω/cm2Preferably 3. omega./cm2～5Ω/cm2(ii) a An undercoat layer 2 formed on the first surface 11 of the metal foil 1 and covering the oxidized region and the non-oxidized region; and an active material layer 3 provided on the undercoat layer 2.
Specifically, as shown in fig. 2, the electrode sheet includes a metal foil 1, an undercoat layer 2, and an active material layer 3. It can be understood that the metal foil 1 has a predetermined length and width, and the length direction of the metal foil 1 is the direction in which the electrode pole piece made of the metal foil is curled to form the cell. The first surface 111 of the metal foil 1 includes a first region 111 and two second regions 112 in the width direction X, and in the width direction X, the first region 111 is located at the center of the first surface 11 of the metal foil 1, the two second regions 112 are distributed on two sides of the first region 111, the first region 111 and the second regions 112 are both in a strip shape and extend along the length direction of the metal foil 1, wherein the first region 111 is an oxidized region, and the second region 112 is a non-oxidized region. The first region 111, i.e. the oxidized region, accounts for 40% to 60%, preferably 43% to 56%, of the total area of the first surface 11 of the metal foil 1. The primer layer 2 is located on the first surface 11 of the metal foil 1 and covers the first area 111 and the second area 112. The primer layer 2 contains a conductive agent and a binder, and can be firmly bonded to the metal foil 1. It is to be understood that the undercoat layer may also be selectively formed on the metal foil at positions corresponding to the first regions.
It is understood that, in the width direction X, the current collector may also be arranged: the metal foil comprises three first areas and two second areas which are alternately distributed, wherein the first areas are oxidized areas, and the second areas are non-oxidized areas. The first area is in a shape of strip, polygon, circle or approximate circle.
And an active material layer 3 provided on the undercoat layer 2.
In some alternative embodiments, the metal foil is aluminum foil, and the aluminum foil in the oxidized region is oxidized to form a hydrated oxide film.
Lithium ion battery
According to a fourth aspect of an embodiment of the present invention, there is provided a lithium ion battery including: the cathode plate, the anode plate, the isolating membrane and the electrolyte. The cathode pole piece and/or the anode pole piece are/is the electrode pole pieces provided in the third aspect of the above embodiments.
The solvent of the electrolyte comprises one or more of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate and ethyl methyl carbonate, and the solute comprises LiPF6、LiBF4、LiBOB、LiAsF6、Li(CF3SO2)2N、LiCF3SO3、LiClO4One or more of them.
The isolating membrane is selected from films which have electrochemical stability and chemical stability and comprise one or more materials of polyethylene, polypropylene, non-woven fabrics and polyfiber materials.
Examples
The present disclosure is more particularly described in the following examples that are intended as illustrations only, since various modifications and changes within the scope of the present disclosure will be apparent to those skilled in the art. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are on a weight basis, and all reagents used in the examples are commercially available and can be used directly without further treatment.
Cathode current collector
The cathode current collector adopts a current collector as shown in figure 1.
Cathode pole piece
The cathode plate is the electrode plate as shown in figure 2.
Anode pole piece
The anode plate is prepared by uniformly stirring an anode active material, a conductive agent and a binder in a certain mass percentage in deionized water, coating the two surfaces of a copper foil (the copper foil adopts a fixed width of 80mm and the thickness of 10 mu m), drying, rolling, slitting, welding a lug and the like.
Electrolyte and isolation film composition
The electrolyte comprises an organic solvent and lithium salt, wherein the organic solvent is a mixture of diethyl carbonate, ethyl methyl carbonate and ethylene carbonate, the volume ratio of the three organic solvents is 1:1:1, and the lithium salt is LiPF6The concentration is 1 mol/L.
A PE/PP/PE three-layer porous polymer film is used as a separation film.
Preparation of lithium ion battery
Winding the cathode plate, the anode plate and the isolating film into a battery cell, and packaging the battery cell by using an aluminum plastic film. The lithium ion battery is prepared by the procedures of vacuum baking, liquid injection, formation aging and the like.
Example 1
The hard shell battery cell and the cathode pole piece adopt the current collector shown in the figure 1, the width is 80mm, the width of the first area, namely the oxidation area is 35mm, and the surface resistance of the aluminum foil is 3 omega cm2The thickness of the primer layer was 6 μm.
Example 2
On the basis of the embodiment 1, the width of the first area, namely the oxidized area, on the surface of the aluminum foil is changed to be adjusted from 35mm to 45mm, and the widths of the two second areas, namely the two non-oxidized areas, are respectively and correspondingly reduced by 5 mm. Other fabrication specifications were kept consistent with example 1.
Example 3
In addition to example 1, the oxidation degree of the first region, i.e., the oxidized region, on the surface of the aluminum foil was increased to set the surface resistance of the aluminum foil to 3. omega. cm2Increase to 10 omega cm2. Other fabrication specifications were kept consistent with example 1.
Comparative example 1
The surface of the aluminum foil is not subjected to oxidation treatment, a primer coating material is directly coated on the surface of the aluminum foil to form a primer coating, and then an active material layer is formed by coating an active material on the primer coating. Other fabrication specifications were kept consistent with example 1.
Test section
The cathode pole piece, the isolating film and the anode pole piece are placed in sequence, the isolating film is positioned between the cathode and the anode to play an isolating role, and the bare cell is obtained by winding. And welding the qualified naked battery cell on the top cover through the lug, and finishing the shelling and baking. And then the lithium ion battery is obtained after the processes of liquid injection, packaging and the like.
And (3) nail penetration test of the lithium ion battery:
fully charging the lithium ion battery at 25 ℃, fixing the lithium ion battery by two steel clamps, penetrating the lithium ion battery by a sharp steel nail with the diameter of 3mm at the speed of 80mm/s along the thickness direction of the lithium ion battery, staying for 60min, observing whether smoke or fire is generated, and detecting the surface temperature of the battery core. The results are shown in Table 1.
And (3) cycle test of the lithium ion battery:
the batteries made in examples and comparative examples were subjected to cycle tests, and charge-discharge cycle tests were carried out at 25 ℃ at a current of 1C (150A), to test the number of cycles at which the capacity decayed to 80%. The results are shown in Table 1.
TABLE 1 Battery Performance test results
In the comparative example 1, the battery core made of the cathode pole piece which is not subjected to oxidation treatment on the surface of the aluminum foil is ignited and burnt in the battery nail penetration test and cannot pass the nail penetration test; the internal resistance of the battery core is 0.90m omega, and the cycle number of the battery is 1000. In example 1, a local area on the surface of the aluminum foil is oxidized to form a hydrated oxide film, and a battery cell made of a cathode plate made of the aluminum foil passes a piercing test effectively and stably, and the surface temperature of the battery cell after piercing is 40-50 ℃, which is remarkably reduced, thus the heat generated by short circuit of the battery cell is remarkably reduced, and the safety performance of the battery is remarkably improved. In example 1, the internal resistance of the cell was 1.10m Ω; the cycle number of the battery is 1400 times, which is improved by 40 percent compared with that of the comparative example 1. In addition, in the embodiment 1, only the surface of the aluminum foil is subjected to oxidation treatment, the difficulty and complexity of the process are not increased, and the subsequent production is easy to implement.
The cells obtained in example 2 passed the nailing test effectively and stably, and compared to example 1, the width of the oxidized region was increased, and the cell surface temperature after nailing was lower, ranging from 30 ℃ to 40 ℃. In example 2, the internal resistance of the cell was 1.20m Ω; the cycle number of the battery is 1200 times, which is improved by 20 percent compared with the comparative example 1. However, compared with example 1, the battery cell manufactured in example 2 has higher internal resistance and correspondingly poorer electrical properties.
The battery cell obtained in example 3 effectively and stably passed the nail penetration test, and compared with example 1, the surface resistance of the aluminum foil was increased, and the surface temperature of the battery cell after nail penetration was lower, ranging from 30 ℃ to 40 ℃. In example 3, the internal resistance of the cell was 1.35m Ω; the cycle number of the battery is 1100, which is improved by 10 percent compared with that of the comparative example 1. However, compared with example 1, the battery cell manufactured in example 3 has higher internal resistance and correspondingly poorer electrical properties.
While the invention has been described with reference to specific embodiments, the invention is not limited thereto, and various equivalent modifications and substitutions can be easily made by those skilled in the art within the technical scope of the invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (10)
1. A current collector, comprising:
the metal foil comprises two opposite surfaces, at least one of the two surfaces is provided with an oxidized region, the oxidized region accounts for 20-60% of the total area of the two surfaces, and the surface resistance of the metal foil is 3 omega/cm2～10Ω/cm2The metal foil is an aluminum foil, and the aluminum foil in the oxidation area is oxidized to form a hydrated oxidation film with a porous structure;
and a primer layer formed on the metal foil.
2. The current collector of claim 1, wherein the metal foil comprises opposing first and second surfaces;
the first surface is provided with the oxidation area, and the oxidation area accounts for 40-60% of the total area of the first surface; and/or the presence of a gas in the gas,
the second surface has the oxidized region, and the oxidized region accounts for 40-60% of the total area of the second surface.
3. The current collector of claim 1, wherein the metal foil comprises first and second opposing surfaces, the first and/or second surfaces being differentiated in a width direction thereof into first and second regions, the first and second regions being alternately distributed in the width direction, the first region being the oxidized region.
4. The current collector of claim 3, wherein the first region is in the shape of a bar, a polygon, a circle, or a near circle.
5. The current collector of claim 4, wherein the first region and the second region are each strip-shaped and extend along a length of the metal foil;
the middle position of the first surface and/or the second surface in the width direction is the first area, and the second area is distributed on both sides of the first area; or,
the first surface and/or the second surface comprise three first regions and two second regions alternately distributed with each other in the width direction thereof.
6. The current collector of any one of claims 3 to 5, wherein the primer layer is formed at least in the first region.
7. A method of manufacturing a current collector, comprising:
covering a protective film on the partial surface of the metal foil, placing the metal foil in pure water at the temperature of 70-100 ℃, or in ammonia water at the temperature of 60-80 ℃, an amine aqueous solution or a mixed solution of ammonia water and amine, and treating for 3600-7200 s; wherein the concentration of the ammonia water is 0.5-1 mol/L; the concentration of the amine aqueous solution is 0.5-1 mol/L; in the mixed solution of the ammonia water and the amine, the total concentration of the ammonia and the amine is 0.5-1 mol/L, and the mass ratio of the ammonia to the amine is 1: 5-5: 1;
carrying out heat treatment on the treated metal foil at the temperature of 300-500 ℃ for 6-8 h to generate a hydrated oxide film on the surface of the metal foil;
and tearing off the protective film covered on the metal foil, coating a base coating material on the metal foil, and drying to form the base coating.
8. The method for manufacturing the current collector as claimed in claim 7, wherein the amine is monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, propylenediamine, diisopropylamine, or aniline.
9. An electrode sheet, characterized in that the electrode sheet comprises a current collector and an active material layer which are sequentially stacked, wherein the current collector is the current collector according to any one of claims 1 to 6.
10. A lithium ion battery, comprising: the cathode pole piece, the anode pole piece, the separation film and the electrolyte, wherein the cathode pole piece and/or the anode pole piece is the electrode pole piece of claim 9.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007250376A (en) * | 2006-03-16 | 2007-09-27 | Nippon Foil Mfg Co Ltd | Aluminum foil for current collector of lithium ion battery and lithium ion battery using the same |
| JP2008103132A (en) * | 2006-10-18 | 2008-05-01 | Furukawa Sky Kk | Aluminum foil for collector of lithium ion cell, and lithium ion cell using it |
| JP5595349B2 (en) * | 2011-07-21 | 2014-09-24 | 株式会社神戸製鋼所 | Positive electrode current collector for lithium ion secondary battery, positive electrode for lithium ion secondary battery, and method for producing positive electrode current collector for lithium ion secondary battery |
| CN104471751A (en) * | 2012-08-09 | 2015-03-25 | 丰田自动车株式会社 | Battery manufacturing method and battery |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102915847A (en) * | 2012-10-16 | 2013-02-06 | 广西贺州市桂东电子科技有限责任公司 | Medium-high voltage electronic aluminum foil corrosion pretreatment method |
| CN104966840A (en) * | 2015-06-24 | 2015-10-07 | 广州鹏辉能源科技股份有限公司 | Lithium ion battery positive current collector high in safety performance, preparing method thereof and lithium ion battery |
| CN106941149A (en) * | 2016-01-04 | 2017-07-11 | 宁德新能源科技有限公司 | Lithium ion battery and its anode pole piece |
-
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Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007250376A (en) * | 2006-03-16 | 2007-09-27 | Nippon Foil Mfg Co Ltd | Aluminum foil for current collector of lithium ion battery and lithium ion battery using the same |
| JP2008103132A (en) * | 2006-10-18 | 2008-05-01 | Furukawa Sky Kk | Aluminum foil for collector of lithium ion cell, and lithium ion cell using it |
| JP5595349B2 (en) * | 2011-07-21 | 2014-09-24 | 株式会社神戸製鋼所 | Positive electrode current collector for lithium ion secondary battery, positive electrode for lithium ion secondary battery, and method for producing positive electrode current collector for lithium ion secondary battery |
| CN104471751A (en) * | 2012-08-09 | 2015-03-25 | 丰田自动车株式会社 | Battery manufacturing method and battery |
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