WO2023151334A1 - High-energy-density positive electrode material, positive electrode sheet and lithium-ion battery - Google Patents

Abstract

The present invention provides a high-energy-density positive electrode material, a positive electrode plate and a lithium-ion battery. The positive electrode material comprises a positive electrode active substance and an additive. The positive electrode sheet comprises a metal current collector and a positive electrode material. The additive is directly coated on the metal current collector together with the positive electrode active substance, or an additive with a micron-level thickness is sprayed on the electrode sheet having the positive electrode active substance. The lithium-ion battery comprises a battery case, an electrode core and an electrolyte. The electrode core and the electrolyte are sealed in the battery case. The electrode core comprises a positive electrode, a negative electrode and a separator between the positive electrode and the negative electrode. The positive electrode comprises a positive electrode current collector and a high-energy-density positive electrode material on the positive electrode current collector. According to the present invention, a specific type of additive is used in the positive electrode material and has extremely high theoretical specific capacity and actual specific capacity. Active lithium with irreversible capacity can be used to supplement lithium consumed by a negative electrode SEI layer, thereby improving the energy density of the power battery and extending the service life of the power battery. The potential safety hazards of an ordinary lithium supplementing technology are avoided.

Description

A kind of high energy density cathode material, cathode pole piece and lithium ion battery technical field

The invention belongs to the technical field of lithium-ion batteries, and in particular relates to a high-energy-density positive electrode material, a positive electrode sheet and a lithium-ion battery.

Background technique

In recent years, the new energy market has continued to develop and mature. With the improvement of vehicle battery life requirements, the demand for lithium-ion batteries with high energy density has increased significantly. At the same time, the use scenarios of new energy vehicles are becoming more and more abundant. For example, lithium-ion batteries are used in cascade utilization of logistics vehicles, buildings, and base stations after being retired from vehicles. It is necessary to further improve the service life of lithium-ion batteries.

However, since the negative electrode active material of lithium-ion batteries is mainly graphite negative electrode, the lithium intercalation potential of graphite negative electrode is lower than the reduction potential of organic electrolytes, such as PC, EC, and DEC. Therefore, during the first charging process, the electrolyte will be reduced to form a solid electrolyte film (SEI) on the surface of the negative electrode. This process not only involves electrons, but also lithium ions. For example, lithium-containing organic substances such as LiF, Li ₂ CO ₃ , such as alkyl lithium carbonate, are generated. Since the graphite negative electrode does not contain lithium in lithium-ion batteries, the positive electrode, as the only source of lithium in the formation of SEI, will cause a loss of 7%-15% of active lithium, which will affect the energy density and service life of the power battery.

In order to improve the energy density and service life of power batteries, extensive lithium supplementation technology research has provided a variety of solutions. For example, lithium supplementation through slurry, that is, metal lithium or lithium-containing organic matter, modified materials, etc., negative electrode materials and non-aqueous liquids are mixed to form a slurry, the slurry is coated on the current collector, and then dried, rolled, injected, etc. Liquid and other processes. Although this method can improve the energy density of lithium-ion batteries, metal lithium has high reactivity and is very easy to react with oxygen and moisture in the air. Therefore, the requirements for moisture control in the preparation process are also extremely strict, thereby increasing the difficulty of the process. At the same time, since lithium-ion batteries have extremely high requirements on the purity of various materials, once impurities are introduced into the lithium-containing materials used, it will have a negative impact on battery performance. Or through surface-treated stable metal lithium powder, but limited by its high activity, it is difficult to use the operating time of the lithium-ion battery process. At the same time, lithium powder is easy to float in the air, posing a great safety hazard. Or use lithium-rich lithium salts, lithium oxides, lithium-containing organic materials and other materials to supplement lithium at the material level at the positive electrode. difficulty.

The prior art discloses a method and system for replenishing lithium on a pole piece. By adding a base material to a metal lithium sheet or a lithium strip, on the one hand, the strength of the lithium strip is enhanced, and on the other hand, a lithium strip is formed between the lithium strip and the composite device. Barrier, so that the lithium ribbon will not be in direct contact with the composite device during the transportation process, thus avoiding the lithium ribbon being torn or pinched during the production process. However, this method has extremely high environmental requirements in the manufacturing process to avoid the reaction of metal lithium with air and water, so it is difficult to apply in practice.

The prior art also discloses negative electrode lithium supplement slurry, negative electrode and lithium secondary battery. Lithium supplement slurry is prepared by using metal lithium powder and prepolymer, and coated on the prepared negative electrode sheet, and then used light or Heating and other conditions cause the prepolymer in the lithium-replenishing slurry to undergo a polymerization reaction to form a macromolecular polymer, and then perform cold pressing to obtain a lithium-replenishing negative electrode sheet. However, this method increases the complexity of making lithium-ion batteries, and it is difficult to maintain the uniformity of the lithium-supplementing slurry of metal lithium powder and prepolymer and the dispersion in the mass production process, and it is prone to sedimentation, resulting in The battery cell consistency is reduced.

The prior art also discloses a method of replenishing lithium to the positive electrode sheet of a lithium-ion battery. By spraying or dripping a uniform organic lithium solution on the surface of the positive electrode sheet, the "wet method lithium replenishment" is realized, thereby effectively avoiding the dry method. The metal lithium powder floats in the air during lithium supplementation to ensure production safety, and the whole process is simple and the cost is low. The amount of lithium supplementation can be adjusted by the amount of organic lithium solution sprayed or dripped, and the time of spraying or dripping Accurate control to achieve the purpose of uniform lithium supplementation, prevent lithium deposition and deformation of the positive plate, improve the first-time efficiency of the battery, and then increase the energy density of the battery. However, this method of lithium supplementation must be implemented in an inert atmosphere to ensure the stability of the highly active organic lithium solution, so it is difficult to apply in practice.

Contents of the invention

The purpose of the present invention is to address the deficiencies of the above-mentioned prior art, to provide a high energy density positive electrode material, and to provide a positive electrode sheet and a lithium-ion battery, mainly to solve the problem of low efficiency of the existing lithium-replenishing methods of lithium-ion batteries. It is complex and has certain security risks.

The purpose of the present invention is achieved by the following technical solutions:

A high-energy-density positive electrode material, the positive electrode material contains positive electrode active materials and _additives , and the additive is the core-shell material of Li ₂ NixMyO ₂ @LFP-X, that is, passing through the outside of the Li _{2 NixMyO 2} material Physically or chemically coat a layer of LFP-X material; where, 0<x≤1, y=1-x, M is Cu, Al, Fe, Mn, Co, Ti, Sb, Mg and other metal elements, or B, F and other non-metallic elements. Further, the LFP-X shell material is a pure-phase LiFePO4 material or a pure-phase LiFePO4 metal-doped LFP-X material, wherein X can be metals such as Mg, Mn, Al, Ti, V, Nb, Sb, etc.

Further, the Li _{2 NixMyO 2} @LFP-X material is made by chemical or physical methods, and the particle size of _the Li ₂ NixMyO ₂ @LFP-X material is 1-10um, wherein Li ₂ NixMyO ₂ The particle size of the core material is 0.5-9.5um, and the particle size of the LFP-X shell material is 0.5-5um.

Furthermore, the chemical method is a solid-phase method or a liquid-phase method, and the solid-phase method is selected from high-temperature solid-phase reaction method, carbothermal reduction method, microwave synthesis and pulsed laser deposition synthesis, sol-gel method, water Thermal synthesis method, precipitation method and solvothermal synthesis method; the physical method is selected from high-energy ball milling and physical vapor deposition method.

Further, the Li ₂ Ni _{x My} O ₂ @LFP-X material is selected as Li ₂ CO ₃ , LiOH, Li ₂ O, CH ₃ COOLi, LiNO ₃ and Li ₂ C ₂ O lithium sources during the preparation process. One or more of ₄ , the iron source is one or more of Fe ₂ O ₃ , FeOOH, Fe(OH) ₃ , Fe(NO3) ₃ , Fe ₂ (SO4) ₃ , the nickel source is NiO, One or more of NiO ₂ , NiOOH, Ni(OH) ₂ , NiNO ₃ , Ni ₂ SO ₄ , metal source, that is, M is Cu, Al, Fe, Mn, Co, Ti, Sb, Mg and other metal elements When , use one or more of MOx, MO(OH)x, M(NO ₃ )x, M(SO ₄ )x, where x depends on the valence state of the metal element.

A positive electrode sheet, including a metal current collector and a high energy density positive electrode material, the additive is directly coated on the metal current collector together with the positive electrode active material, or the additive with a thickness of micron is sprayed on the electrode sheet with the positive electrode active material.

Further, the mass percentage of the additive and the positive electrode active material is a, 0%<a≤50%.

Furthermore, the mass percentage of the additive and the positive electrode active material is 5%-15%.

Furthermore, after the additive is prepared into a slurry, it is coated on the surface of the positive electrode active material sheet by spraying, screen printing, or doctor blade, with a thickness of 1-10 um.

A lithium-ion battery, the lithium-ion battery includes a battery case, a pole core and an electrolyte, the pole core and the electrolyte are sealed in the battery case, the pole core includes a positive pole, a negative pole, and a battery between the positive pole and the negative pole The separator, the positive electrode includes a positive electrode current collector and a high energy density positive electrode material on the positive electrode current collector.

Compared with prior art, the beneficial effect of the present invention is:

1. The present invention provides a high-energy-density positive electrode material, a pole piece and a lithium-ion battery. The present invention uses a specific type of additive in the positive electrode material as a core-shell material of Li ₂ Ni _{x My} O ₂ @LFP-X, Among them, Li ₂ Ni _{x My} O ₂ has extremely high theoretical specific capacity and actual specific capacity, which can reach 300-600mAh/g;

2. At the same time, after charging and delithiation, due to the destruction of the structure of the lithium-rich material, some lithium ions cannot be reintercalated during discharge, so it has a higher charge capacity and a lower discharge capacity, so as to realize the use of active lithium with its irreversible capacity Supplement the consumption of negative electrode SEI film;

3. The remaining reversible capacity of the additive material enables it to act as a positive electrode active material during battery use, which improves the energy density and life of the power battery;

4. In addition, because a layer of LFP-X material is physically or chemically coated on the outside of the Li ₂ Ni _{x My} O ₂ material, it is ensured that the additive can be processed in the same way as the general positive active material in the production process of lithium-ion batteries. It can be directly coated on the positive electrode metal current collector together with the positive electrode active material, or sprayed on the electrode sheet with the positive electrode active material to make a high energy density positive electrode sheet without additional manufacturing processes or Environmental control is easier to implement in actual production and avoids the safety hazards of general lithium supplementation technology.

Description of drawings

In order to illustrate the technical solutions of the embodiments of the present invention more clearly, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and thus It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.

Figure 1 is a schematic diagram of the core-shell material of Li ₂ Ni _x M _y O ₂ @LFP-X;

Figure 2 is a schematic diagram of a high energy density positive pole piece;

Figure 3 Lithium-ion battery charge and discharge curve for the first time.

Detailed ways

The present invention will be further described below in conjunction with embodiment:

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, but not to limit the present invention. In addition, it should be noted that, for the convenience of description, only some structures related to the present invention are shown in the drawings but not all structures.

It should be noted that like numerals and letters denote similar items in the following figures, therefore, once an item is defined in one figure, it does not require further definition and explanation in subsequent figures. Meanwhile, in the description of the present invention, the terms "first", "second", etc. are only used to distinguish descriptions, and cannot be understood as indicating or implying relative importance.

As shown in Figure 1, the present invention provides a high-energy-density positive electrode material. The positive electrode material contains positive electrode active materials and additives, and the additive is a core-shell material of Li ₂ NixMyO ₂ @LFP-X, that is, in Li ₂ The Ni _x M _y O ₂ material is physically or chemically coated with a layer of LFP-X material. Among them, 0<x≤1, y=1-x, M is Cu, Al, Fe, Mn, Co, Ti, Sb, Mg and other metal elements, or B, F and other non-metallic elements, in order to achieve its specific capacity up to It can reach 300-600mAh/g, or even higher.

At the same time, after charging and delithiation, due to the destruction of the structure of the lithium-rich material, some lithium ions cannot be reintercalated during discharge, so it has a higher charge capacity and a lower discharge capacity, so as to realize the use of its irreversible capacity to supplement the negative electrode with active lithium. Depletion of the SEI film.

The remaining reversible capacity of the additive enables it to act as a positive electrode active material during battery use, so as to improve the energy density and prolong the service life of the power battery. The additive is physically or chemically coated with a layer of LFP-X material on the outside of the Li ₂ Ni _x My _{O 2} material, which ensures the stability of the additive in the air, and can be compared with general positive active materials during storage or manufacturing. The processing method is the same.

The LFP-X shell material can be a pure phase LiFePO4 material, or a pure phase LiFePO4 metal-doped LFP-X material, wherein X can be Mg, Mn, Al, Ti, V, Nb, Sb and other metals , to improve the electrical conductivity inside the pure-phase LiFePO4 crystal.

The Li ₂ Ni _x M _y O ₂ @LFP-X material can be synthesized by chemical methods, such as solid-phase method, that is, high-temperature solid-phase reaction method, carbothermal reduction method, microwave synthesis and pulsed laser deposition method; or liquid Phase methods, such as sol-gel method, hydrothermal synthesis method, precipitation method and solvothermal synthesis method. Physical methods can also be used, such as high energy ball milling, physical vapor deposition and other methods. The particle size of the Li ₂ NixMyO ₂ @LFP-X material is 1-10um, of which the particle size of the core material of Li ₂ NixMyO ₂ is 0.5-9.5um, and the particle size of the LFP-X shell material is 0.5-5um.

The Li ₂ Ni _x M _y O ₂ @LFP-X material can be selected as a lithium source in the preparation process of Li ₂ CO ₃ , LiOH, Li ₂ O, CH ₃ COOLi, LiNO ₃ and Li ₂ C ₂ O ₄ one or more of.

The iron source selected in the preparation process of the L Li ₂ Ni _x M _y O ₂ @LFP-X material can be Fe ₂ O ₃ , FeOOH, Fe(OH) ₃ , Fe(NO3) ₃ , Fe ₂ (SO4) One or more of ₃ .

The nickel source selected in the preparation process of the Li ₂ Ni _{x My} O ₂ @LFP-X material can be one of NiO, NiO ₂ , NiOOH, Ni(OH) ₂ , NiNO ₃ , Ni ₂ SO ₄ or Various.

The metal source selected in the preparation process of the Li ₂ Ni _x M _y O ₂ @LFP-X material, that is, when M is a metal element such as Cu, Al, Fe, Mn, Co, Ti, Sb, Mg, etc., MOx can be used One or more of , MO(OH)x, M(NO ₃ )x, M(SO ₄ )x, where x depends on the valence state of the metal element.

The additive is prepared together with the positive electrode active material and coated on the positive electrode metal current collector, wherein the mass percentage of the additive and the positive electrode active material is a, 0%<a≤50%, preferably 5%-15%, The above slurry preparation and coating process are the same as the known general technology in the industry, and there is no need for additional environmental control and process procedures, as shown in Figure 2.

The additive material is prepared into a slurry using a known general technology in the industry, and is coated on the surface of the positive electrode active material electrode sheet by spraying, screen printing, or scraping, with a thickness of 1-10 um, as shown in Figure 2.

The invention provides a high-energy-density positive pole piece, the pole piece includes a metal current collector and a positive electrode material, the additive can be directly coated on the metal current collector together with the positive active material, or sprayed on the pole piece with the positive active material Additive materials with a thickness of 1-10um at the micron level.

The additive has high stability, and its particle size and surface energy are similar to those of general positive electrode materials. It can be directly prepared with the positive electrode active material and coated on the positive electrode metal current collector without additional manufacturing process or environmental control. , which is easier to realize in actual production, and at the same time avoids the safety hazards of general lithium supplementation technology.

The additive can be made into a lithium-supplementing slurry separately, and the additive material with a micron-level thickness can be sprayed and transferred on the pole piece with the positive active material, and the thickness can be 1-10um. After the first charge and delithiation are completed, the A more stable protective layer is formed on the surface of the positive electrode active material to improve the safety of lithium-ion batteries under abuse conditions. At the same time, the separate additive slurry ensures the consistency of additive distribution on the pole piece.

According to the high energy density positive electrode material and positive electrode sheet of the present invention, it can be used to prepare lithium-ion batteries, and the positive electrode material is lithium iron phosphate, lithium cobaltate, lithium manganate, lithium nickelate, lithium-rich manganese base, nickel-cobalt-manganese Ternary, nickel-cobalt-aluminum ternary type, the negative electrode material is graphite, metal lithium, alloy type. At the same time, it can be used for lithium-ion batteries of different packaging types, including hard-shell square, soft-pack and cylindrical.

The invention provides a lithium-ion battery, the lithium-ion battery includes a battery case, a pole core and an electrolyte, the pole core and the electrolyte are sealed in the battery case, the pole core includes a positive pole, a negative pole, and a A separator between negative electrodes, the positive electrode includes a positive electrode collector and a positive electrode material on the positive electrode collector, and the positive electrode material is the positive electrode material provided by the present invention.

The lithium-ion battery adopts the positive electrode material provided by the present invention, that is, contains positive electrode active material and additive material, and is calculated by matching with the design of the negative electrode. The mass percentage of the additive and the positive electrode active material is a, and generally 0%<a≤50 %, preferably 5%-15%. The additive has no requirement on the type of positive electrode material, such as LFP, NCM, LMO, LTO, etc. commonly used in the industry, and has a wide range of applications.

The additive has no requirement on the type of negative electrode material, such as Gr, LTO, Gr-nano Si, Gr- _SiOx , etc. commonly used in the industry, and has a wide range of applications.

The additive has no requirement on the type of diaphragm material, such as PP, PE, ceramic coating, PVDF coating modified diaphragm, etc. commonly used in the industry, and has a wide range of applications.

The additives have no requirements on the type of electrolyte materials, such as LiPF6, LiBOB, LiFSI electrolytes commonly used in the industry, and EC, DEC, DMC organic solutions, etc., and have a wide range of applications.

Compared with the prior art, the high energy density cathode material, pole piece and lithium ion battery of the present application have at least the following improvements:

1. The content of additives is significantly increased, which greatly improves the efficiency of lithium supplementation, and at the same time greatly improves the energy density and life of lithium-ion batteries.

2. The stability of the lithium supplement additive material is significantly improved. Compared with the raw materials containing metal lithium strips and lithium powder, it avoids the problem of potential safety hazards.

3. Compared with other lithium supplementation methods, the processing technology complexity is significantly reduced. There is no need to provide additional manufacturing processes or environmental controls, and it is easier to implement in actual production.

Example 1

Mix Li ₂ O and NiO with a molar ratio of 1-1.5:1 as raw materials, and sinter in an argon-protected environment with a heating rate of 5°C/min, a sintering temperature of 600-800°C, and a sintering time of 5-15h , Li ₂ NiO ₂ material can be obtained, and then in an argon-protected environment, mix it with a nano-LFP material with a mass percentage of 2%-5% for 5-20h using a high-energy ball mill to make the nano-LFP material on Li ₂ NiO ₂ A uniform coating is formed to obtain Li ₂ NiO ₂ @LFP material.

Example 2

Mix Li ₂ CO ₃ and FePO ₄ with a molar ratio of 1-1.05:1 as raw materials, glucose ratio 16%, add 0.5-2% Mg ₂ (OH) ₂ CO ₃ , use ethanol as dispersant, and mix by ball milling 6-10h, after vacuum drying at 80-100°C, sintering, the sintering temperature is 700-800°C, and the sintering time is 8-12h, the shell material of LFP-Mg can be obtained, and then the mass percentage is 95% The -98% Li ₂ Ni _0.5 Cu _0.5 O ₂ material is mixed with a high-energy ball mill for 5-20 hours to obtain the Li ₂ Ni _0.5 Cu _0.5 O ₂ @LFP-Mg material.

Example 3

Mix Li ₂ NiO ₂ @LFP and LFP as raw materials with a mass ratio of 1.05-1.15:1, where Li ₂ NiO=@LFP is an additive, LFP is a positive electrode active material, and then add 0.5-1% conductive agent SP and viscose Adhesive PVDF, using NMP as dispersant, using planetary agitation and mixing for 3-5h to prepare positive electrode material slurry, and using transfer coating method to coat and compress the actual density of 2.4-2.5mg/m2 on aluminum foil with a thickness of 12um High-energy cathode material pole piece.

Example 4

To prepare a lithium-ion battery, use the high-energy positive electrode material pole piece, graphite negative electrode, and separator in Example 3 to prepare and wind up to prepare a bare cell, then put the bare cell into the shell, inject liquid, and then place the battery in an environment of 25°C After standing still, the formation, shaping and degassing processes are carried out after the electrolyte is infiltrated, and finally a lithium-ion battery with high energy density is obtained, and its first efficiency can be found to be >99% in the formation test stage, as shown in Figure 3.

As shown in Figure 3, compared with the unsupplemented lithium battery, the lithium-ion battery containing Li2NiO2@LFP additive has a first-time efficiency of >99%.

Note that the above are only preferred embodiments of the present invention and applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, rearrangements and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and can also include more other equivalent embodiments without departing from the concept of the present invention, and the present invention The scope is determined by the scope of the appended claims.

Claims (10)

1. A high energy density positive electrode material, characterized in that: the positive electrode material contains a positive electrode active material and an additive, and the additive is a core-shell material of Li ₂ NixMyO ₂ @LFP-X, that is, in Li ₂ Ni _{x My} O ₂ The outside of the material is physically or chemically coated with a layer of LFP-X material; where, 0<x≤1, y=1-x, M is Cu, Al, Fe, Mn, Co, Ti, Sb, Mg and other metal elements , or B, F and other non-metallic elements.
2. A high energy density positive electrode material according to claim 1, characterized in that: the LFP-X shell material is a pure phase LiFePO4 material or a pure phase LiFePO4 metal-doped LFP-X material, wherein X can be Mg , Mn, Al, Ti, V, Nb, Sb and other metals.
3. A high energy density cathode material according to claim 1, characterized in that _: said Li _{2 NixMyO 2} @LFP-X material is made by chemical or physical methods, Li ₂ NixMyO ₂ @LFP The particle size of the -X material is 1-10um, the particle size of the core material of Li ₂ NixMyO ₂ is 0.5-9.5um, and the particle size of the LFP-X shell material is 0.5-5um.
4. A high-energy-density cathode material according to claim 3, characterized in that: the chemical method is a solid-phase method or a liquid-phase method, and the solid-phase method is selected from high-temperature solid-phase reaction method, carbothermal reduction method, microwave Synthesis and pulse laser deposition synthesis, sol-gel method, hydrothermal synthesis method, precipitation method and solvothermal synthesis method; the physical method is high-energy ball milling and physical vapor deposition method.
5. A high energy density positive electrode material according to claim 1, characterized in that: the lithium source selected in the preparation process of the Li ₂ Ni _{x My} O ₂ @LFP-X material is Li ₂ CO ₃ , LiOH, One or more of Li ₂ O, CH ₃ COOLi, LiNO ₃ and Li ₂ C ₂ O ₄ , the iron source is Fe ₂ O ₃ , FeOOH, Fe(OH) ₃ , Fe(NO3) ₃ , Fe ₂ ( One or more of SO4) ₃ , the nickel source is one or more of NiO, NiO ₂ , NiOOH, Ni(OH) ₂ , NiNO ₃ , Ni ₂ SO ₄ , the metal source, that is, M is Cu, For metal elements such as Al, Fe, Mn, Co, Ti, Sb, Mg, use one or more of MOx, MO(OH)x, M(NO ₃ )x, M(SO ₄ )x, where x Depends on the valence state of the metal element.
6. A positive electrode sheet, including a metal current collector and a high energy density positive electrode material, the additive is directly coated on the metal current collector together with the positive electrode active material, or the additive with a thickness of micron is sprayed on the electrode sheet with the positive electrode active material.
7. The positive pole piece according to claim 6, characterized in that: the mass percentage of the additive and the positive active material is a, 0%<a≤50%.
8. The positive pole piece according to claim 6, characterized in that: the mass percentage of the additive and the positive active material is 5%-15%.
9. A positive pole piece according to claim 6, characterized in that: after the additive is prepared into a slurry, it is coated on the surface of the positive pole active material pole piece by a spraying method, a screen printing method, or a doctor blade method, and the thickness 1-10um.
10. A lithium-ion battery, characterized in that: the lithium-ion battery includes a battery case, a pole core and an electrolyte, the pole core and the electrolyte are sealed in the battery case, the pole core includes a positive pole, a negative pole, and a and a separator between the negative electrode, the positive electrode includes a positive electrode current collector and a high energy density positive electrode material on the positive electrode current collector.

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