CN114843436A

CN114843436A - Electrode slice, battery and electronic equipment

Info

Publication number: CN114843436A
Application number: CN202210538126.9A
Authority: CN
Inventors: 杨帆; 彭冲; 李俊义
Original assignee: Zhuhai Cosmx Battery Co Ltd
Current assignee: Zhuhai Cosmx Battery Co Ltd
Priority date: 2022-05-17
Filing date: 2022-05-17
Publication date: 2022-08-02

Abstract

The invention provides an electrode plate, a battery and electronic equipment, wherein the electrode plate comprises a current collector, and a coating layer and an active substance layer which are respectively formed on the current collector, the coating layer is arranged on the surface of at least one side of the current collector, and the active substance layer is arranged on the coating layer; wherein the impedance of the paint layer is proportional to the temperature. Like this, through set up the dope layer between mass flow body and active substance layer, and the impedance and the temperature of dope layer are directly proportional, lead to the inside temperature of battery to rise when the misoperation, the impedance of dope layer increases rapidly under the condition that reaches preset temperature to block the electron route between the pole piece, thereby reduce the battery and appear the short circuit and arouse the condition such as conflagration, explosion, improve the security of battery.

Description

Electrode slice, battery and electronic equipment

Technical Field

The invention relates to the technical field of batteries, in particular to an electrode plate, a battery and electronic equipment.

Background

Lithium batteries are widely used in the fields of mobile communication, transportation, energy storage and the like. However, since the lithium battery has high energy, most of the electrolyte is flammable organic matter, once the battery is over-charged, over-discharged, punctured, squeezed or dropped, the heat generation rate of the battery is higher than the heat release rate, and the conditions of smoking, fire, explosion and the like may occur, which causes personal and property loss.

At present, overcharge protection of lithium batteries is mainly realized by arranging a special external circuit, a blast valve or a temperature control component, but the protection modes need higher cost, and the blocking of the circuit in the lithium battery has hysteresis.

It can be seen that the battery in the prior art has the problem of low safety.

Disclosure of Invention

The embodiment of the invention provides an electrode plate, a battery and electronic equipment, and aims to solve the problem of low battery safety in the prior art.

The embodiment of the invention provides an electrode plate, which comprises a current collector, and a coating layer and an active substance layer which are respectively formed on the current collector, wherein the coating layer is arranged on the surface of at least one side of the current collector, and the active substance layer is arranged on the coating layer;

wherein the impedance of the paint layer is proportional to the temperature.

Optionally, the coating layer comprises polytetrafluoroethylene, PTFE, nanoparticles.

Optionally, the PTFE nanoparticles have a median diameter in the range of 0.2 microns to 5 microns.

Optionally, the paint layer further includes a first binder and a first conductive agent, and the PTFE nanoparticles, the first binder, and the first conductive agent are mixed.

Optionally, the paint layer further includes at least one of titanium dioxide, aluminum oxide, magnesium oxide, zinc oxide, zirconium oxide, cerium oxide, ferrous oxide, barium sulfate, boehmite, lithium iron phosphate, lithium iron manganese phosphate, polyurethane microspheres, polystyrene microspheres, and polyethylene microspheres.

Optionally, the thickness of the coating layer is 0.8 to 10 microns.

Optionally, the dope layer is respectively disposed on the surface of the current collector opposite to each other, and the active substance layer is respectively disposed on the surface of one side of the dope layer away from the current collector.

Optionally, the mass flow body one end is provided with utmost point ear, keeping away from of dope layer utmost point ear one end is in respectively there is the spacing distance between the projection on the mass flow body.

Optionally, a projection of the active material layer on the current collector is located within the coating layer.

Optionally, the active material layer includes an active material, a second binder, and a second conductive agent, which are mixedly disposed.

Optionally, the active material comprises at least one of lithium cobaltate, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminate, lithium iron phosphate, and lithium rich manganese.

Optionally, the first conductive agent comprises at least one of conductive carbon black, acetylene black, ketjen black, conductive graphite, conductive carbon fiber, carbon nanotube, metal powder, and carbon fiber;

and/or the first binder comprises at least one of polyamide, polyvinylidene fluoride, polyacrylic acid, lithium polyacrylate, sodium polyacrylate, polyester, polyether, epoxy resin, polyvinyl acetate, polyimide, polybutadiene, polyphenyl propylene, methyl methacrylate, sodium polymethylcellulose and lithium polymethylcellulose.

The embodiment of the invention also provides a battery, which comprises a first pole piece, a diaphragm and a second pole piece, wherein the first pole piece and/or the second pole piece are/is the electrode pieces, the diaphragm is arranged between the first pole piece and the second pole piece, and the first pole piece and the second pole piece are wound after being stacked to form a winding core.

The embodiment of the invention also provides electronic equipment, which comprises the battery.

In the embodiment of the invention, the coating layer is arranged between the current collector and the active material layer, and the impedance of the coating layer is in direct proportion to the temperature, so that when the internal temperature of the battery is increased due to improper operation, the impedance of the coating layer is rapidly increased under the condition of reaching the preset temperature to block an electronic path between the pole pieces, thereby reducing the conditions of fire, explosion and the like caused by short circuit of the battery and improving the safety of the battery.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive labor.

Fig. 1 is a schematic structural diagram of an electrode sheet provided in an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without inventive step based on the embodiments of the present invention, are within the scope of protection of the present invention.

The terms first, second and the like in the description and in the claims of the present invention are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the structures so used are interchangeable under appropriate circumstances such that embodiments of the invention may be practiced in sequences other than those illustrated or described herein, and that the terms "first", "second", etc. are generally used herein as a class and do not limit the number of terms, for example, a first term can be one or more than one. In addition, "and/or" in the specification and claims means at least one of connected objects, a character "/" generally means that a preceding and succeeding related objects are in an "or" relationship.

Referring to fig. 1, fig. 1 is a schematic structural diagram of an electrode sheet according to an embodiment of the present invention, and as shown in fig. 1, an electrode sheet according to an embodiment of the present invention includes a current collector 101, and a coating layer 102 and an active material layer 103 respectively formed on the current collector 101, where the coating layer 102 is disposed on at least one side surface of the current collector 101, and the active material layer 103 is disposed on the coating layer 102;

wherein, the impedance of the paint layer 102 is proportional to the temperature, and the paint layer 102 is used for blocking the electronic path at a preset temperature.

In the embodiment, the coating layer 102 is arranged between the current collector 101 and the active material layer 103, and the impedance of the coating layer 102 is in direct proportion to the temperature, so that when the internal temperature of the battery rises due to improper operation, the impedance of the coating layer 102 is rapidly increased when the preset temperature is reached, an electronic path between pole pieces is blocked, the situations of fire, explosion and the like caused by short circuit of the battery are reduced, and the safety of the battery is improved.

For example, overcharge, overdischarge, needle stick, extrusion, dropping, etc. of the battery lead to rapid increase of the battery voltage, collapse of the electrode plate structure and oxidation of the electrolyte, which may cause rapid increase of the internal pressure and temperature of the battery, possibly cause short circuit in the battery, and risk of gas generation expansion and explosion fire in the battery.

In some embodiments, the coating layer 102 may be described as follows: a polymer adhesive may be used as the semiconductor heating ceramic PTC in the coating layer 102, and when the temperature rises, the adhesive in the coating layer 102 swells, so that the thickness of the coating layer 102 increases to break the conductive network in the electrode sheet.

In other embodiments, polytetrafluoroethylene PTFE nanoparticles may be included in the coating layer 102. The PTFE material is a fluorinated high molecular compound of ethylene, and because four hydrogen ions are all replaced by fluorine atoms, the stability of the PTFE material is better, and common substances are difficult to attach to the surface of the PTFE material at high temperature. The paint layer 102 further includes a first binder and a first conductive agent, and the PTFE nanoparticles, the first binder and the first conductive agent are mixed. When the PTFE nanoparticles are mixed with the first binder and the first conductive agent to form the coating layer 102, the first binder and the first conductive agent can be peeled off from the PTFE nanoparticles when the temperature is raised to a preset temperature, so that the conductive network of the coating layer 102 is damaged, the resistance of the coating layer 102 is raised, an electronic path between the pole pieces is blocked, and the safety of the battery is improved.

Wherein the preset temperature may range from 100 ℃ to 110 ℃.

Alternatively, the median diameter (D50 particle size) of the PTFE nanoparticles may range from 0.2 microns to 5 microns. The smaller the particle size of D50, the better the anti-overcharge effect.

Alternatively, the thickness of the coating layer 102 may be 0.8 to 10 microns. When the thickness of the coating layer 102 is too thin, the active material layer 103 is easily brought into direct contact with the current collector 101 during roll pressing, and when the thickness of the coating layer 102 is too thick, the coating layer 102 deteriorates rate capability and lowers energy density.

The particle size range of the PTFE nano-particles can be 0.2-5 microns through verification, the thickness of the coating layer 102 can be 0.8-10 microns, the impedance can be rapidly improved when the temperature is increased, and meanwhile, the influence on the cycle performance of the battery is small during normal use.

It should be noted that the PTFE material may also be disposed in the coating layer 102 in the form of a glue solution, and the same technical effect can be achieved, and for avoiding repetition, the details are not described herein again.

The paint layer 102 may further include a filler in addition to the PTFE nanoparticles, the first binder, and the first conductive agent, so as to achieve an improvement effect of overcharge or other performances in different degrees, where the filler may include at least one of titanium dioxide, aluminum oxide, magnesium oxide, zinc oxide, zirconium oxide, cerium oxide, ferrous oxide, barium sulfate, boehmite, lithium iron phosphate, lithium iron manganese phosphate, polyurethane microspheres, polystyrene microspheres, and polyethylene microspheres. The filler may have a D50 particle size of less than or equal to 5 microns to balance the reduction in rate, increase in internal resistance due to overcharge improvement, or to improve other safety properties of the battery.

Alternatively, the coating layers 102 are respectively disposed on the surfaces of the current collector 101 on the opposite sides, and the active material layers 103 are respectively disposed on the surfaces of the coating layers 102 on the sides far away from the current collector 101.

In this embodiment, the coating layer 102 is made by mixing PTFE nanoparticles, a first binder, a first conductive agent, and a filler; the coating layer 102 can be coated on the surfaces of the two opposite sides of the current collector 101 by a gravure coater, the coating thickness on one side can be 5um, and the coating layer 102 containing PTFE is formed on the surfaces of the two opposite sides of the current collector 101 after high-temperature drying. Then, active material layers 103 are respectively disposed on the coating layers 102 on both sides of the current collector 101. The impedance of the coating layer 102 is in direct proportion to the temperature, when the internal temperature of the battery rises due to misoperation, the impedance of the coating layer 102 is rapidly increased under the condition that the internal temperature reaches the preset temperature so as to block electronic paths on two sides of the current collector 101, thereby reducing the conditions of fire, explosion and the like caused by short circuit of the battery and improving the safety of the battery.

Optionally, one end of the current collector 101 is provided with a tab 104, and there is a spacing distance between projections of ends of the coating layers 102 far away from the tab 104 on the current collector 101, respectively.

In the present embodiment, a tab 104 may be provided at one end of the current collector 101 to collect current. The length that the dope layer 102 of mass flow body one side laid on the mass flow body 101 is greater than the length that the dope layer 102 of mass flow body opposite side laid on the mass flow body 101, make there is the interval distance between the projection of the dope layer 102 of keeping away from utmost point ear 104 one end respectively on the mass flow body 101, and the great dope layer 102 of length of laying on the mass flow body 101 faces the outside of core, increase the coverage of core outside dope layer 102 on the mass flow body 101 in the process that the electrode slice winding formed the core, thereby promote the speed that core outside position blocked the electronic circuit under the preset temperature, reduce the battery and appear the short circuit and arouse the conflagration, circumstances such as explosion, the security of battery is improved.

Optionally, the projection of the active material layer 103 on the current collector 101 is located within the coating layer 102.

In this embodiment, the projection of the active material layer 103 on the current collector 101 is located in the coating layer 102, in other words, the coating length of the coating layer 102 on one side of the current collector 101 is greater than or equal to the coating length of the active material layer 103 on the side, so that the active material layer 103 is connected with the current collector 101 through the coating layer 102, and the impedance of the coating layer 102 is proportional to the temperature, so as to cut off the electronic channel when the temperature is high, thereby improving the safety of the battery.

Alternatively, the active material layer 103 may include an active material, a second binder, and a second conductive agent that are mixedly disposed. The active material layer 103 is formed by mixing and disposing the active material, the second binder, and the second conductive agent, and is applied to the coating layer 102 to promote the lithium ion migration rate.

The first conductive agent or the second conductive agent may include at least one of conductive carbon black, acetylene black, ketjen black, conductive graphite, conductive carbon fiber, carbon nanotube, metal powder, and carbon fiber, and may provide a sufficient electron transport network during normal use of the battery.

The first binder or the second binder can comprise at least one of polyamide, polyvinylidene fluoride, polyacrylic acid, lithium polyacrylate, sodium polyacrylate, polyester, polyether, epoxy resin, polyvinyl acetate, polyimide, polybutadiene, polyphenyl propylene, methyl methacrylate, sodium polymethyl cellulose and lithium polymethyl cellulose, and the first binder or the second binder can play a role in binding materials and enhancing the stability.

The active material comprises at least one of lithium cobaltate, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminate, lithium iron phosphate and lithium-rich manganese.

In some alternative embodiments, the process of preparing the coating layer 102 can be described as follows:

PTFE nano particles can be selected, the first conductive agent can be conductive carbon black, the first binder can be polyvinylidene fluoride PVDF, the PTFE nano particles, the PVDF and the conductive carbon black are added into a stirring tank according to the mass ratio of 92:6:2, N-methyl pyrrolidone (NMP) is added, and PTFE overcharge improved slurry with the solid content of 30% is obtained through stirring; the PTFE overcharge improvement slurry can be coated on both surfaces of the current collector 101 by using a 120-mesh gravure coater, the coating thickness can be 5um, and the coating layer 102 containing PTFE is obtained after high-temperature drying.

In some alternative embodiments, the process of preparing the active material layer 103 may be described as follows:

the active material can be lithium cobaltate, the second conductive agent can be conductive carbon black, the second binder can be PVDF, the lithium cobaltate, the PVDF and the conductive carbon black are added into a stirring tank according to the mass ratio of 97:2:1, N-methyl pyrrolidone (NMP) is added, and positive active material slurry with the solid content of 70% is obtained through stirring; the positive active material slurry may be applied to a surface of the coating layer 102 away from the current collector 101 using an extrusion coater, and the coating thickness of the active material layer 103 may be 60 um.

And drying at high temperature to obtain the electrode plate containing the PTFE coating layer 102 and the active substance layer 103.

The embodiment of the invention also provides a battery, which comprises a first pole piece, a diaphragm and a second pole piece, wherein the first pole piece and/or the second pole piece can be the above electrode pieces, the diaphragm is arranged between the first pole piece and the second pole piece, and the first pole piece and the second pole piece are wound after being stacked to form a winding core. The first pole piece and the second pole piece can be arranged in a stacked mode or in a winding mode to form the battery cell.

The process for preparing the second pole piece can be described as follows:

graphite, sodium carboxymethylcellulose (CMC-Na), styrene-butadiene rubber and acetylene black are mixed according to the mass ratio of 97: 1: 1: 1, adding deionized water as a solvent, stirring by a vacuum stirrer to obtain slurry containing 50% of negative active materials, coating the negative active materials on two surfaces of a copper foil by using an extrusion coater, wherein the coating thickness can be 80 microns, and drying in an oven after coating to obtain a second pole piece.

The diaphragm is arranged between the first pole piece (namely the electrode piece) and the second pole piece, the first pole piece and the second pole piece are stacked and wound to form a winding core, and the winding core is subjected to the working procedures of hot pressing, packaging, liquid injection, formation and the like to obtain the lithium ion battery.

It should be noted that other materials, such as at least one of lithium nickel cobalt manganese oxide, lithium manganate, lithium nickel manganese oxide, lithium nickel cobalt aluminate, lithium iron phosphate, and lithium-rich manganese, may also be used as the active material, which may achieve the same technical effects, and is not described herein again in order to avoid repetition.

It should be noted that the first conductive agent or the second conductive agent may also be made of other materials, such as at least one of acetylene black, ketjen black, conductive graphite, conductive carbon fiber, carbon nanotube, metal powder, and carbon fiber, which may achieve the same technical effect and are not described herein again to avoid repetition.

It should be noted that the first binder or the second binder may also be made of other materials, such as at least one of polyamide, polyacrylic acid, lithium polyacrylate, sodium polyacrylate, polyester, polyether, epoxy resin, polyvinyl acetate, polyimide, polybutadiene, polyphenylpropylene, methyl methacrylate, sodium polymethylcellulose, and lithium polymethylcellulose, which may achieve the same technical effect and are not described herein again to avoid repetition.

Example 1:

firstly, adding PTFE nano particles with D50 of 0.7um, PVDF and carbon black into a stirring tank according to the mass ratio of 92:6:2, adding NMP, and stirring to obtain PTFE overcharge improvement slurry with the solid content of 30%; coating the PTFE overcharge improvement slurry on two surfaces of a current collector 101 by using a 120-mesh gravure coater, wherein the coating thickness can be 5um, and drying at high temperature to obtain a coating layer 102 containing PTFE.

Secondly, adding 16um lithium cobaltate D50, PVDF and carbon black into a stirring tank according to the mass ratio of 97:2:1, adding NMP, and stirring to obtain positive active material slurry with solid content of 70%; coating the positive active material slurry on one surface, far away from the current collector 101, of the coating layer 102 by using an extrusion coating machine, wherein the coating thickness can be 60 micrometers, and drying at high temperature to obtain a first pole piece containing the PTFE coating layer 102 and the active material layer 103;

and rolling and slitting the obtained first pole piece to obtain a pole piece with the size of 1300mm and the width of 80 mm. The pole piece is through cross section analysis, and the thickness of PTFE coating is 3um, and the thickness of anodal active material layer is 35 um.

And thirdly, preparing a second pole piece. Graphite, sodium carboxymethylcellulose (CMC-Na), styrene-butadiene rubber and acetylene black are mixed according to the mass ratio of 97: 1: 1: 1, adding deionized water as a solvent, stirring by a vacuum stirrer to obtain slurry containing 50% of negative active materials, coating the negative active materials on two surfaces of a copper foil by using an extrusion coater, wherein the coating thickness can be 80 microns, and drying in an oven after coating to obtain a second pole piece.

And fourthly, assembling the battery. Stacking the first pole piece, the diaphragm and the second pole piece in sequence, and winding to form a winding core; and carrying out hot pressing, packaging, liquid injection, formation and other processes on the winding core to obtain the lithium ion battery.

Example 2:

example 2 differs from example 1 in that: the coater in the first step of example 2 used a 100 mesh gravure roll, so that the thickness of the paint layer 102 was set to 7 um.

Example 3:

example 3 differs from example 1 in that: the coater in the first step of example 3 used a 140 mesh gravure roll, so that the thickness of the paint layer 102 was set to 3 um.

Example 4:

example 4 differs from example 1 in that: in the first step of example 4, the PTFE nanoparticles, PVDF and carbon black were added to a stirred tank at a mass ratio of 70:26:4 and stirred.

Example 5:

example 5 differs from example 1 in that: in the first step of example 5, the PTFE nanoparticles, PVDF and carbon black were added to a stirred tank at a mass ratio of 50:44:6 and stirred.

Comparative example 1 can also be provided, with comparative example 1 having no PTFE containing coating layer 102, and the remaining parameters and procedure being in accordance with example 1.

The above examples 1 to 5 and comparative example 1 were subjected to the 3C-5V overcharge test, the 1C-6V overcharge test and the cycle performance test.

In the 3C-5V overcharge test:

the batteries respectively manufactured in examples 1 to 5 and comparative example 1 were placed in an ambient temperature environment, the batteries in each example and comparative example were discharged to 3.0V at 0.2C, left to stand for 10 minutes and then charged to 5V at a current of 3C, and then charged at a constant voltage of 5V and maintained for 60 minutes, and it was considered that the batteries did not ignite and did not burn.

In the 1C-6V overcharge test:

the batteries respectively manufactured in examples 1 to 5 and comparative example 1 were placed in an ambient temperature environment, the batteries in each example and comparative example were discharged to 3.0V at 0.2C, left to stand for 10 minutes and then charged to 6V at a current of 1C, and then charged at a constant voltage of 6V and maintained for 60 minutes, and it was considered that the batteries did not ignite and did not burn.

In the cycle performance test:

the batteries in each of the examples and comparative examples were charged to a cut-off voltage at 0.7C, discharged to 3.0V at 0.5C after 0.025C cut-off, and subjected to a cyclic charge and discharge test in this mode, and 5 batteries in each group were tested, and the average of the test results of the 5 batteries was taken to obtain a capacity retention ratio after 500 cycles (500T) of the battery (the capacity retention ratio is the capacity after 500T of the battery cycle/the initial capacity before the battery cycle).

The results of 3C-5V overcharge, 1C-6V overcharge, and cycling performance tests were recorded for examples 1-5 and comparative example 1, respectively, as shown in Table 1 below:

table 1: results of the related tests of examples 1-5 and comparative example 1

Case(s)	3C-5V passage	1C-6V passage rate	Retention rate of circulating capacity
				Example 1	10/10	10/10	94.13％
Example 2	10/10	10/10	92.72％
				Example 3	5/10	1/10	92.41％
Example 4	8/10	5/10	93.66％
				Example 5	6/10	4/10	90.39％
Comparative example 1	3/10	0/10	94.85％

As can be seen from table 1 above, the addition of the PTFE material in the coating layer 102 can significantly improve the overcharge performance of the lithium ion battery, and has no significant deterioration to the performance of the battery, and when the temperature is raised to the preset temperature, the first binder and the first conductive agent can be peeled off from the PTFE nanoparticles, so that the conductive network of the coating layer 102 is damaged, and the resistance of the coating layer 102 is raised, thereby blocking the electronic path between the first pole piece and the second pole piece, and improving the safety of the battery.

The first pole piece can be a positive pole piece, and the second pole piece can be a negative pole piece.

The embodiment of the invention provides electronic equipment, which comprises the battery.

The electronic device may be a notebook computer, a smart phone, or the like, and is not limited herein. The implementation manner of the embodiment of the battery is also suitable for the embodiment of the electronic device, and can achieve the same technical effect, which is not described herein again.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element. Furthermore, it should be noted that the scope of the methods and apparatus of embodiments of the present invention is not limited to performing functions in the order discussed, but may include performing functions in a substantially simultaneous manner or in a reverse order depending on the functionality involved, e.g., the methods described may be performed in an order different than that described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.

While the present invention has been described with reference to the embodiments shown in the drawings, the present invention is not limited to the embodiments, which are illustrative and not restrictive, and it will be apparent to those skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. An electrode plate is characterized by comprising a current collector, and a coating layer and an active substance layer which are respectively formed on the current collector, wherein the coating layer is arranged on at least one side surface of the current collector, and the active substance layer is arranged on the coating layer;

wherein the impedance of the paint layer is proportional to the temperature.

2. An electrode sheet as defined in claim 1, wherein the coating layer comprises Polytetrafluoroethylene (PTFE) nanoparticles.

3. The electrode sheet of claim 2, wherein the PTFE nanoparticles have a median diameter in the range of 0.2 to 5 microns.

4. The electrode sheet of claim 2, wherein the coating layer further comprises a first binder and a first conductive agent, and the PTFE nanoparticles, the first binder and the first conductive agent are mixed.

5. The electrode sheet of claim 2, wherein the coating layer further comprises at least one of titanium dioxide, aluminum oxide, magnesium oxide, zinc oxide, zirconium oxide, cerium oxide, ferrous oxide, barium sulfate, boehmite, lithium iron phosphate, lithium iron manganese phosphate, polyurethane microspheres, polystyrene microspheres, and polyethylene microspheres.

6. The electrode sheet of claim 1, wherein the thickness of the paint layer is 0.8 to 10 micrometers.

7. The electrode sheet according to claim 1, wherein the coating layers are respectively disposed on the surfaces of the current collector on the opposite sides, and the active material layers are respectively disposed on the surfaces of the coating layers on the sides away from the current collector.

8. The electrode plate as defined in claim 7, wherein one end of the current collector is provided with a tab, and the projections of the ends of the coating layers, which are far away from the tab, on the current collector are spaced apart.

9. The electrode sheet of claim 1, wherein a projection of the active material layer on the current collector is located within the coating layer.

10. The electrode sheet according to claim 4, wherein the first conductive agent includes at least one of conductive carbon black, acetylene black, ketjen black, conductive graphite, conductive carbon fiber, carbon nanotube, metal powder, and carbon fiber;

11. A battery comprising a first pole piece, a separator and a second pole piece, the first pole piece and/or the second pole piece being an electrode sheet according to any one of claims 1 to 10, the separator being disposed between the first pole piece and the second pole piece.

12. An electronic device characterized in that it comprises a battery as claimed in claim 11.