CN113839041A - Positive pole piece, preparation method thereof and battery comprising positive pole piece - Google Patents
Positive pole piece, preparation method thereof and battery comprising positive pole piece Download PDFInfo
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- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
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- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
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- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
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- H01—ELECTRIC ELEMENTS
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- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
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- H01M4/02—Electrodes composed of, or comprising, active material
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- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/139—Processes of manufacture
- H01M4/1391—Processes of manufacture of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
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- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
- H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
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- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/028—Positive electrodes
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Abstract
The invention provides a positive pole piece, a preparation method thereof and a battery comprising the positive pole piece. The positive pole piece comprises a body and a simple substance metal layer coated on the surface of the body, can absorb oxygen released by the positive pole piece, solves the problem that the battery positive pole in the prior art generates oxygen and endangers the safety of the battery, and is suitable for the field of electrode pole piece preparation.
Description
Technical Field
The invention relates to the field of electrode plate preparation, in particular to a positive electrode plate, a preparation method thereof and a battery comprising the positive electrode plate.
Background
High energy density Lithium Ion Batteries (LIBs) are the key to driving the next generation of sustainable energy technologies. The oxygen-containing anode is a main component of a high-voltage and high-energy-density lithium ion battery. Since graphite is used as the negative electrode in most commercial lithium ion batteries, the electrochemical performance (e.g., energy density and operating voltage) of the battery is determined by the choice of the positive electrode material. The main technical route at present is to use a high-nickel and high-voltage anode material, and the problem brought by the increase of the high gram capacity of the anode material is the reduction of the thermal stability. The anode material is decomposed at high temperature and high pressure, a large amount of oxygen is released to cause severe degradation of the anode performance, and a large amount of heat and energy are rapidly released to endanger the safety of the battery, and thermal runaway, namely ignition of the battery, is triggered. Thermal runaway events occur from notebook computers, mobile phones to electronic cigarettes, earphones, electric vehicles and even airplanes, and serious damage is caused to consumers. Therefore, the inhibition of oxygen release of the cathode material plays an important role in the safety aspect of the lithium ion battery.
In the prior art, a method of adding or coating an oxygen remover in a positive plate is generally adopted, and an internal oxygen self-absorption safe lithium battery is reported. It is also reported that a high-nickel ternary cathode material containing an active oxygen remover is disclosed, and the effect of inhibiting oxygen release is achieved by coating the surface of the cathode with a metal sulfide as the oxygen remover. However, the oxygen remover used in the prior art has poor conductivity, so that the impedance of the positive plate is increased, and the cycle performance of the battery is reduced.
Disclosure of Invention
The invention mainly aims to provide a positive pole piece, a preparation method thereof and a battery comprising the positive pole piece, so as to solve the problem that the battery positive pole in the prior art generates oxygen and endangers the safety of the battery.
In order to achieve the above object, according to one aspect of the present application, a positive electrode plate is provided, which includes a body and a simple substance metal layer coated on a surface of the body.
Furthermore, the purity of the single metal in the single metal layer is 99.99-99.999%.
Further, the elemental metal is selected from any one or more of: silver, copper, lead, tin, iron, zinc or aluminum.
Further, the thickness of the simple substance metal layer is 1-500 nm.
Furthermore, the material of the body of the positive pole piece comprises a positive active substance, conductive carbon and a binder.
According to a second aspect of the present application, there is provided a method for preparing a positive electrode sheet, the method comprising: and providing a body of the positive pole piece, and coating the surface of the body with a simple substance metal layer to obtain the positive pole piece.
Further, the preparation method adopts a vacuum evaporation method, a sputtering film forming method or an electron beam evaporation method to coat the surface of the body with the simple substance metal layer; preferably, the purity of the single metal in the single metal layer is 99.99-99.999%; preferably, the elemental metal is selected from any one or more of: silver, copper, lead, tin, iron, zinc or aluminum; preferably, the thickness of the elemental metal layer is 1 to 500 nm.
Further, the preparation method adopts a vacuum evaporation method to coat the surface of the body with the simple substance metal layer, and the obtained positive pole piece comprises the following steps: attaching the body to a position of an evaporation mask plate, placing an evaporation boat and a simple substance metal to be evaporated at the position of an evaporation source, performing evaporation in a vacuum state of an evaporation equipment cavity, and cooling after evaporation to obtain a positive pole piece; preferably, the evaporation rate of the vacuum evaporation method is
Preferably, the degree of vacuum in the vacuum state is 10-3-10-5Pa。
Further, the body of the positive electrode plate provided in the preparation method comprises: preparing a positive active substance, conductive carbon and a binder into slurry; coating the slurry on a positive current collector to obtain a positive pole piece precursor; drying and rolling the precursor of the positive pole piece in sequence to obtain a body of the positive pole piece; preferably, the solvent of the binder is an NMP solution; preferably, the mass content of the positive active substance in the body of the positive pole piece is 85-99%; preferably, the mass content of the binder in the body of the positive pole piece is 0.5-14.5%; preferably, the mass content of the conductive carbon in the body of the positive pole piece is 0.5-14.5%.
According to a third aspect of the present application, a battery is provided, which includes a positive electrode plate, the positive electrode plate or the positive electrode plate prepared by the above preparation method.
By applying the technical scheme of the invention, the simple substance metal layer capable of absorbing oxygen released by the positive pole piece is arranged on the surface of the positive pole piece, so that the conductivity of the electrode, the safety of the battery and the electrochemical performance are improved.
Detailed Description
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail with reference to examples.
As mentioned in the background art, the inventors of the present application have conducted intensive studies on the oxygen remover of the battery, and have proposed a positive electrode plate, a method for preparing the same, and a battery comprising the same, because the problems in the prior art, such as the safety of the battery is endangered by the oxygen generated by the positive electrode of the battery, and the cycle performance of the battery is affected by the poor conductivity of the existing oxygen remover. The invention utilizes equipment such as vacuum evaporation equipment to evaporate high-purity simple substance metal onto the positive plate body to form a uniform and compact metal layer. The metal layer has good conductivity, can improve the conductivity of the positive electrode, reduce the internal resistance and improve the cycle performance; meanwhile, the metal layer has reducibility, and oxygen released by the anode can be reduced in the charging and discharging processes, so that the effects of relieving oxygen release of the anode and reducing gas generation are achieved. When the battery is out of control due to thermal runaway and the anode material rapidly releases oxygen, the oxygen can be rapidly absorbed, the occurrence of combustion and explosion of the battery is avoided or delayed, and the safety of the battery is improved.
Thus, in the present application, the inventors tried to prepare a button cell by using a positive electrode plate having a simple substance silver layer on the surface of the body. Tests prove that the anode plate with the elemental silver layer can improve the cycle performance of the battery. Thus a series of protection schemes of the present application are proposed.
In one embodiment of the present invention, a positive electrode plate is provided, which includes a body and a simple substance metal layer coated on the surface of the body. The simple substance metal layer has good conductivity, can improve the conductivity of the positive electrode, reduce the internal resistance and improve the cycle performance; because the simple substance metal layer has reducibility, oxygen released by the anode can be reduced in the charging and discharging processes, so that the effects of relieving oxygen release of the anode and reducing gas generation are achieved; when the battery is out of control due to thermal runaway and the anode material rapidly releases oxygen, the simple substance metal layer can rapidly absorb the oxygen, so that the occurrence of combustion and explosion of the battery is avoided or delayed, and the safety of the battery is improved.
In the positive pole piece, the purity of the single metal in the single metal layer is 99.99-99.999%.
In the positive electrode sheet, the elemental metal in the elemental metal layer includes, but is not limited to, any one or more of the following: silver, copper, lead, tin, iron, zinc or aluminum.
The thickness of the simple substance metal layer of the positive pole piece is 1-500 nm.
The material of the body of the positive pole piece includes but is not limited to positive active material, conductive carbon and binder.
The high-purity elemental metal in the elemental metal layer can ensure the conductivity, the reduction and the oxygen absorption performance of the positive pole piece; the elementary metal comprises one or more of silver, copper, lead, tin, iron, zinc or aluminum, has good conductivity, can reduce and absorb oxygen released by the anode, and can play a role in the form of pure metal or alloy; the elementary metal layers with different thicknesses can provide different conductivity and oxygen reduction and absorption performances, the thickness can be conveniently changed by changing the coating conditions, and the elementary metal layers with different thicknesses can be optimized according to different battery types and performance requirements. The positive pole piece body can be composed of positive active substances, conductive carbon, a binder and other materials, and the simple substance metal layer can be coated on the surface of the existing positive pole piece bodies with different specifications, so that the aims of improving the conductivity and the safety of the battery are fulfilled.
In a second embodiment of the present invention, a method for preparing a positive electrode sheet is provided, the method comprising: and providing a body of the positive pole piece, and coating the surface of the body with a simple substance metal layer to obtain the positive pole piece. The preparation method can coat the simple substance metal layer after the positive pole piece body is prepared, and the production line operation is carried out to improve the production efficiency; the original positive pole piece body can also be subjected to secondary processing, and a single-substance metal layer is coated to obtain the positive pole piece with the upgraded conductivity and safety.
In the preparation method, a simple substance metal layer is coated on the surface of the body by a vacuum evaporation method, a sputtering film forming method or an electron beam evaporation method; preferably, the purity of the single metal in the single metal layer is 99.99-99.999%; preferably, the elemental metals include, but are not limited to, any one or more of the following: silver, copper, lead, tin, iron, zinc or aluminum; preferably, the thickness of the elemental metal layer is 1 to 500 nm.
According to the property difference of different anode pole piece bodies, the types, thicknesses and the like of the simple substance metal, the simple substance metal layer can be coated on the surface of the body by selecting a vacuum evaporation method, a sputtering film forming method, an electron beam evaporation method and the like. The high-purity elemental metal in the elemental metal layer can ensure the conductivity, the reduction and the oxygen absorption performance of the positive pole piece; the elementary metal comprises but is not limited to one or more of silver, copper, lead, tin, iron, zinc or aluminum, the elementary metal has good conductivity, oxygen released by the anode can be reduced and absorbed by utilizing the reducibility of the metal, and the stronger the reducibility is, the stronger the oxygen absorption capacity is, and the elementary metal can play a role in the form of pure metal or alloy; the elementary metal layers with different thicknesses can provide different conductivity and oxygen reduction and absorption performances, the thickness can be conveniently changed by changing the process conditions for coating the elementary metal layers, and the elementary metal layers can be optimized according to different battery types and performance requirements.
In the above preparation method, the coating of the elemental metal layer on the surface of the body by the vacuum evaporation method to obtain the positive electrode piece includes: stick the main body toAt the position of a vapor plating mask plate, placing an evaporation boat and elementary metal to be evaporated at the position of an evaporation source, performing vapor plating in a vacuum state of a cavity of vapor plating equipment, and cooling after vapor plating to obtain a positive pole piece; preferably, the evaporation rate of the vacuum evaporation method is
Preferably, the degree of vacuum in the vacuum state is 10-3-10-5Pa。
The vacuum evaporation method adopted in the preparation method is a process method which adopts a heating evaporation mode to evaporate and gasify the coating material and fly particles to the surface of the substrate to condense and form a film under the vacuum condition. The method has the advantages of mature process, simple film forming method, high film purity and compactness and capability of ensuring the stability of the process. By optimizing the evaporation rate, the vacuum degree and other process conditions, the coated elemental metal layer can be ensured to meet the design requirements, the coated elemental metal layer is uniformly and compactly distributed on the surface of the positive plate, and the elemental metal cannot be oxidized in the preparation process. The evaporation boat can be made of molybdenum, tungsten, tantalum and other metals.
In the existing method, a physical adsorbent is directly added in the preparation process of the pole piece, or a solid-phase sintering method is utilized to prepare a reducing coating layer. The physical adsorbents added are mostly adsorbents such as aluminosilicate, zeolite, activated carbon, carbon black or molecular sieve with poor conductivity, and influence the conductivity of the electrode. The metal-coated anode material is prepared by a solid-phase sintering method, nano-scale metal simple substance particles are required to be coated, the cost is high, and the nano-scale metal simple substance particles are easily oxidized in the sintering process due to large surface area, so that the effect of inhibiting oxygen release of the anode is weakened, and the conductivity is also influenced, so that the requirement on the gas atmosphere in the sintering process is very strict, and the cost and the process difficulty are further improved; if the nano-scale metal simple substance particles are not adopted for sintering and coating, the process requirement of uniform coating is difficult to achieve, and the effects of influencing the conductivity and inhibiting the oxygen release of the positive electrode are influenced. The invention provides a protective layer directly on the positive plate, which is a research from a battery system; in the prior art, the coating of the metal or nonmetal positive electrode particles is researched from the beginning of materials, the difference between the positive electrode particles and the nonmetal positive electrode particles is great, and the process steps are completely different. Therefore, compared with a particle coating layer prepared by a solid-phase sintering method, the method for preparing the anode plate with the simple substance metal layer by the evaporation method has more advantages.
In the above preparation method, providing the body of the positive electrode sheet includes: preparing raw materials such as a positive active substance, conductive carbon, a binder and the like into slurry; coating the slurry on a positive current collector to obtain a positive pole piece precursor; drying and rolling the precursor of the positive pole piece in sequence to obtain a body of the positive pole piece; preferably, the solvent of the binder may be an NMP solution; preferably, the mass content of the positive active substance in the body of the positive pole piece is 85-99%; preferably, the mass content of the binder in the body of the positive pole piece is 0.5-14.5%; preferably, the mass content of the conductive carbon in the body of the positive pole piece is 0.5-14.5%.
The positive pole piece body in the preparation method can be prepared by mixing a positive active material, conductive carbon, a binder or other raw materials, preparing slurry, coating the slurry on a positive current collector such as copper foil, aluminum foil and the like by using a coating method such as a scraper and the like to obtain a positive pole piece precursor, drying, and rolling to the same thickness to obtain the positive pole piece body. The solvent used for the binder or other ingredients may be N-methylpyrrolidone (NMP) or other suitable solvent. The mass ratio of the positive active material, the conductive carbon and the binder can be flexibly configured so as to ensure the performance requirement of the positive plate body.
In a second embodiment of the present invention, a battery is provided, which includes a positive electrode plate, wherein the positive electrode plate is the positive electrode plate or the positive electrode plate prepared by the above preparation method. The battery can effectively relieve oxygen release of the anode material, reduce side reaction between the anode and the electrolyte, and improve the safety performance and the cycle performance of the battery.
The advantageous effects of the present application will be explained in further detail below with reference to specific examples.
Example 1
Preparing a positive plate: 2.118g of PVDF NMP solution with the solid content of 6.25 percent, 1.6g of NMP solution, 0.136g of conductive carbon and positive active substance (L)iNi0.8Co0.1Mn0.1O2)3.148g, homogenizing, coating (scraper gap 22 μm), drying, and rolling to the same thickness to obtain the positive plate.
Fixing the positive plate on a vapor deposition mask plate, placing the mask plate on a substrate plate of a vapor deposition chamber, placing 0.4g of metal silver (with purity of 99.99%) in an evaporation boat (made of molybdenum) and fixing the evaporation boat on an evaporation source until the vacuum degree of the chamber reaches 10-3After Pa, the evaporation arc current is gradually increased until the evaporation rate is stabilized at
Continuously evaporating silver on the surface of the positive plate at the speed, stopping evaporation when the thickness of the evaporation layer reaches 10nm, and taking out the positive plate after the positive plate is cooled to room temperature to obtain the positive plate with the uniform metallic silver layer.
The negative electrode is lithium metal, the diaphragm is a PE diaphragm, and the electrolyte is LiPF6(the concentration in the electrolyte is 1M) is dissolved in a mixed solution of Ethylene Carbonate (EC)/diethyl carbonate (DEC)/Ethyl Methyl Carbonate (EMC) in a volume ratio of 1:1:1, and the button cell is assembled with a positive plate with a metal silver layer on the surface to test the electrochemical performance.
Example 2
The only difference from example 1 is: evaporating by using an evaporation boat made of tungsten until the vacuum degree of a chamber reaches 10-5After Pa, the evaporation arc current is gradually increased until the evaporation rate is stabilized at
Silver is continuously evaporated on the surface of the positive plate at the speed.
Example 3
The difference from example 1 is: evaporating by using an evaporation boat made of tantalum until the vacuum degree of a chamber reaches 10-4After Pa, the evaporation arc current is gradually increased until the evaporation rate is stabilized at
Silver is continuously evaporated on the surface of the positive plate at the speed.
Example 4
The difference from example 1 is: evaporating by using an evaporation boat made of tungsten until the vacuum degree of a chamber reaches 10-4After Pa, the evaporation arc current is gradually increased until the evaporation rate is stabilized at
Silver is continuously evaporated on the surface of the positive plate at the speed.
Example 5
The difference from example 1 is: evaporating by using an evaporation boat made of tungsten until the vacuum degree of a chamber reaches 10-2After Pa, the evaporation arc current is gradually increased until the evaporation rate is stabilized at
Silver is continuously evaporated on the surface of the positive plate at the speed.
Example 6
The only difference from example 1 is: and stopping evaporation when the thickness of the evaporation layer reaches 1 nm.
Example 7
The only difference from example 1 is: and stopping evaporation when the thickness of the evaporation layer reaches 100 nm.
Example 8
The only difference from example 1 is: and stopping evaporation when the thickness of the evaporation layer reaches 200 nm.
Example 9
The only difference from example 1 is: and stopping evaporation when the thickness of the evaporation layer reaches 500 nm.
Example 10
The only difference from example 1 is: and stopping evaporation when the thickness of the evaporation layer reaches 550 nm.
Example 11
The only difference from example 1 is: the purity of the metallic silver was 99.90%.
Examples 12 to 18
The only difference from example 1 is: the elementary metals are copper, lead, tin, iron, zinc, aluminum and manganese respectively.
Example 19
The only difference from example 1 is: the positive pole piece bodies are different, and the preparation methods are respectively as follows:
example 19: taking 1.642g of PVDF NMP solution with the solid content of 6.25%, 1.6g of NMP solution, 0.103g of conductive carbon and 3.109g of positive electrode active substance, homogenizing, coating (the gap between scrapers is 22 mu m), drying, and rolling to the same thickness to obtain the positive electrode sheet.
Example 20:
the only difference from example 1 is: the positive pole piece bodies are different, and the preparation methods are respectively as follows:
taking 1.094g of PVDF NMP solution with the solid content of 6.25%, 1.6g of NMP solution, 0.068g of conductive carbon and 3.283g of positive electrode active substance, homogenizing, coating (the gap between scrapers is 22 mu m), drying, and rolling to the same thickness to obtain the positive electrode sheet.
Example 21:
the only difference from example 1 is: the active substances in the positive pole piece are different in types, and the positive active substance is LiNi0.75Mn0.25O2。
Example 22:
1g of aluminum powder and 99g of a positive electrode active material (LiNi)0.8Co0.1Mn0.1O2) Adding the materials into a mixing device for mixing, treating the mixed materials for 5 hours at the high temperature of 700 ℃ in a nitrogen atmosphere, and cooling to obtain the aluminum-coated anode material.
2.118g of PVDF NMP solution with the solid content of 6.25 percent, 1.6g of NMP solution and 0.136g of conductive carbon are taken as the raw materials of the coated positive active material (LiNi)0.8Co0.1Mn0.1O2)3.148g, homogenizing, coating (scraper gap 22 μm), drying, and rolling to the same thickness to obtain the positive plate.
Comparative example 1
Preparing a positive plate: 0.3808g of PVDF NMP solution with the solid content of 6.25%, 1.6g of NMP solution, 0.136g of conductive carbon and 3.148g of positive electrode active substance are taken, homogenized, coated (the gap between scrapers is 22 mu m), dried and rolled to the same thickness to obtain the positive electrode sheet.
The negative electrode is lithium metal, the diaphragm is a PE diaphragm, and the electrolyte is LiPF6(the concentration in the electrolyte is 1M) is dissolved in a mixed solution of Ethylene Carbonate (EC)/diethyl carbonate (DEC)/Ethyl Methyl Carbonate (EMC) in a volume ratio of 1:1:1, and the button cell is assembled with the positive plate to test the electrochemical performance.
Comparative example 2
The only difference from comparative example 1 is: the active substances in the positive pole piece are different in types, and the positive active substance is LiNi0.75Mn0.25O2。
The oxygen release temperature indicates that the anode material starts to release oxygen as the temperature of the anode rises to a certain temperature, and the battery explodes and burns when the temperature continues to rise and reaches thermal runaway. The purpose of the present invention is to increase the temperature at which the positive electrode material starts to release oxygen, thereby delaying the time at which thermal runaway occurs. The mass fraction reduction rate and the oxygen release temperature were measured by thermogravimetry-mass spectrometry (TG-MS).
TABLE 1
From the above description, it can be seen that the above-described embodiments of the present invention achieve the following technical effects: according to the invention, the electrode pole piece body is coated with the elemental metal layer on the surface of the electrode pole piece body, so that oxygen release of the anode material can be effectively relieved, side reaction between the anode and the electrolyte is reduced, and the safety performance and the cycle performance of the battery are improved.
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. The positive pole piece is characterized by comprising a body and a simple substance metal layer coated on the surface of the body.
2. The positive electrode plate of claim 1, wherein the purity of the elemental metal in the elemental metal layer is 99.99% -99.999%.
3. The positive electrode sheet according to claim 2, wherein the elemental metal is selected from any one or more of the following: silver, copper, lead, tin, iron, zinc or aluminum.
4. The positive electrode sheet according to any one of claims 1 to 3, wherein the thickness of the elemental metal layer is 1 to 500 nm.
5. The positive electrode plate as claimed in claim 4, wherein the material of the body comprises a positive active material, conductive carbon and a binder.
6. A preparation method of a positive pole piece is characterized by comprising the following steps:
providing a body of the positive pole piece,
and coating a simple substance metal layer on the surface of the body to obtain the positive pole piece.
7. The production method according to claim 6, wherein the elemental metal layer is coated on the surface of the body by a vacuum evaporation method, a sputtering film formation method, or an electron beam evaporation method;
preferably, the purity of the single metal in the single metal layer is 99.99-99.999%;
preferably, the elemental metal is selected from any one or more of: silver, copper, lead, tin, iron, zinc or aluminum;
preferably, the thickness of the elementary metal layer is 1-500 nm.
8. The preparation method of claim 7, wherein the step of coating the surface of the body with an elemental metal layer by using the vacuum evaporation method to obtain the positive electrode piece comprises the following steps:
attaching the body to a position of a vapor plating mask plate, placing an evaporation boat and the elementary metal to be evaporated at the position of an evaporation source, performing vapor plating in a vacuum state of a cavity of vapor plating equipment, and cooling after the vapor plating to obtain the positive pole piece;
preferably, the evaporation rate of the vacuum evaporation method is
Preferably, the degree of vacuum of the vacuum state is 10-3-10-5Pa。
9. The method of claim 7 or 8, wherein providing the body of the positive electrode sheet comprises:
preparing a positive active substance, conductive carbon and a binder into slurry;
coating the slurry on a positive current collector to obtain a positive pole piece precursor;
drying and rolling the positive pole piece precursor in sequence to obtain a body of the positive pole piece;
preferably, the solvent of the binder is an NMP solution;
preferably, the mass content of the positive active material in the body of the positive pole piece is 85-99%;
preferably, the mass content of the binder in the body of the positive pole piece is 0.5-14.5%;
preferably, the mass content of the conductive carbon in the body of the positive pole piece is 0.5-14.5%.
10. A battery, which comprises a positive pole piece, and is characterized in that the positive pole piece is the positive pole piece in any one of claims 1 to 5 or the positive pole piece prepared by the preparation method in any one of claims 6 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111027748.7A CN113839041B (en) | 2021-09-02 | 2021-09-02 | Positive pole piece, preparation method thereof and battery comprising positive pole piece |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114464908A (en) * | 2022-04-13 | 2022-05-10 | 四川新能源汽车创新中心有限公司 | Three-dimensional porous coating for lithium ion battery and preparation and application thereof |
| CN115224264A (en) * | 2022-08-29 | 2022-10-21 | 江苏欧力特能源科技有限公司 | Protective lithium battery positive electrode material and preparation method thereof |
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| CN115224264B (en) * | 2022-08-29 | 2024-02-09 | 江苏欧力特能源科技有限公司 | Protective lithium battery positive electrode material and preparation method thereof |
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