WO2014134967A1

WO2014134967A1 - Positive electrode film of lithium ion battery and preparation and application therefor

Info

Publication number: WO2014134967A1
Application number: PCT/CN2013/091128
Authority: WO
Inventors: 王辰云; 刘现军; 刘杨; 方燕群; 王德宇
Original assignee: 中国科学院宁波材料技术与工程研究所
Priority date: 2013-03-05
Filing date: 2013-12-31
Publication date: 2014-09-12
Also published as: CN109659496A; CN104037418A

Abstract

Provided is a positive electrode film of a lithium battery, comprising: (i) a positive electrode material of a lithium intercalated transition metallic oxide; (ii) a lithium ion replenisher; and (iii) a conductive agent and an adhesive. The lithium ion replenisher in the positive electrode film decomposes during initial charging and then releases lithium ions, so as to make up for a loss of lithium ions forming an SEI film on a negative electrode surface, thereby improving the reversible charging and discharging capacity of the lithium ion battery. In the prepared positive electrode film, the lithium ion replenisher can be mixed in the positive electrode material or the conductive agent in advance, and can be coated on the surface of the positive electrode of the lithium ion battery as well.

Description

Positive electrode film of lithium ion battery and preparation and application thereof

Technical field

The invention belongs to the field of lithium ion batteries. In particular, the present invention relates to a positive electrode film for a lithium ion battery and its preparation and use. Background technique

Since its commercialization in the early 1980s, lithium-ion batteries have been widely used in portable electronic devices such as mobile phones, notebook computers, and compact cameras because of their high voltage, high specific energy, long cycle life, and no environmental pollution. Lithium-ion batteries can also replace traditional non-renewable resources such as oil and natural gas, and are more widely used in power tools, electric bicycles, electric vehicles, solar cells and wind energy storage, satellite and aerospace, etc. It plays an important role in saving non-renewable energy.

So far, lithium ion cathode materials mainly include lithium cobaltate, lithium nickelate, lithium nickel cobaltate, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminate, lithium manganate, lithium iron phosphate, lithium manganese phosphate, lithium vanadium phosphate. Compounds and their modified complexes. The commercial anode materials mainly include surface-modified natural graphite, mesocarbon microspheres, lithium titanate, a small amount of amorphous carbon, hard carbon, artificial graphite, and carbon silicon materials, silicon materials, and nitrogen-based materials under study. , bismuth based materials, metal alloys, etc. The electrolyte is mainly a mixture of one or more of an organic solvent such as a carbonate, an ether or a nitrile and a solute such as lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium dioxalate borate or lithium difluorooxalate borate. Solution.

In lithium ion batteries, can provide energy transfer medium and an electrolyte solute material in only the positive electrode is a lithium ion Li ⁺ in the battery charging and discharging process. It has been proved that in the first charge-discharge cycle of a lithium ion battery, a solid electrolyte film (SEI) is formed on the surface of the negative electrode material of the lithium battery, and lithium ions in the lithium ion and the electrolyte are accompanied by the cycle of the lithium battery. It cannot be completely removed after being embedded in the negative electrode material. These two conditions lead to a decrease in the capacity of the lithium battery and a decrease in the cycle efficiency, especially in the first cycle.

At present, the commonly used battery additives include three aspects of negative electrode additive, electrolyte additive and conductive agent additive, which are applied to negative electrode film formation, flame retardant and anti-overcharge functions. For example, in Chinese Patent No. 201010611339. 7, a negative electrode additive is disclosed, wherein the negative electrode additive has the general formula F (CF2CF2) m* (CH2CH20) n-R. Among them, the addition of the fluorine-containing ether compound can make the anode slurry mix more uniformly, increase the electrolyte retention, and improve the capacity and cycle performance of the battery to some extent, but the preparation method is complicated, and more toxic substances are produced. Therefore, there is an urgent need in the art to develop a method and product for solving the lithium ion battery field in the charge and discharge cycle of a lithium battery, reducing its capacity attenuation and improving its cycle efficiency. Summary of the invention

In view of the above problems of capacity attenuation and cycle efficiency of a lithium ion battery, it is an object of the present invention to provide a lithium ion battery positive electrode film containing a lithium ion replenisher and a corresponding battery.

In a first aspect of the invention, a positive electrode film for a lithium battery is provided, and the positive electrode film comprises:

(i) a lithium intercalation transition metal oxide cathode material;

(ii) a lithium ion extender doped into the positive electrode material or the conductive agent and/or applied to the surface of the positive electrode of the lithium ion battery;

(iii) Conductive agents and binders.

In another preferred embodiment, the lithium intercalation transition metal oxide cathode material is selected from the group consisting of lithium cobaltate, lithium nickelate, lithium nickel cobaltate, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminate, and manganic acid. Lithium, lithium iron phosphate, lithium manganese phosphate, lithium vanadium phosphate, or a combination thereof.

In another preferred embodiment, the conductive agent includes carbon black, graphite, carbon nanotubes, graphene, and the like. In another preferred embodiment, the binder comprises polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), carboxymethyl cellulose (CMC), a copolymer of styrene and butadiene (SBR). ).

In another preferred embodiment, the positive electrode film further contains a current collector aluminum foil.

In another preferred embodiment, the lithium ion extender comprises: a lithium oxygen compound, a lithium salt, a ruthenium lithium compound, or a combination thereof.

In another preferred embodiment, the lithium oxygen compound comprises: lithium oxide, lithium peroxide, lithium superoxide, or a combination thereof;

The mercaptolithium compound comprises: lithium methoxide, lithium ethoxide, lithium isopropoxide, ethyl lithium, isopropyl lithium, butyl lithium or a combination thereof;

The lithium salt includes: lithium carbonate, lithium borohydride, lithium fluoride, lithium nitride, lithium sulfide, lithium persulfide, or a combination thereof.

In another preferred embodiment, the lithium ion extender is in a solid or liquid state.

In a further preferred embodiment, the lithium ion-replenishing agent has a mass percentage of the lithium intercalated metal oxide positive electrode material of 0.5 to 10%, more preferably 1 to 3%.

According to a second aspect of the present invention, a lithium battery positive electrode film according to the first aspect of the present invention is provided The method includes: (al) providing a positive electrode material slurry, the slurry comprising a lithium intercalation transition metal oxide positive electrode material, a lithium ion supplement, and a conductive agent and a binder; and the slurry a positive electrode film is formed by vacuum drying after coating the tablet; or

The method comprises: (a2) mixing a lithium ion supplement with a conductive agent, adding a lithium intercalation transition metal oxide positive electrode material and a binder, and forming a positive electrode film by vacuum drying after coating the tablet; or

The method comprises: (a3) applying a lithium ion extender to the surface of the positive electrode of the dried lithium ion battery, thereby forming a positive electrode film of the lithium battery containing the lithium ion extender.

According to a third aspect of the invention, there is provided a lithium ion battery comprising the battery positive electrode film of the first aspect of the invention.

In another preferred embodiment, the lithium ion battery further includes a negative electrode film, a separator, an electrolyte, a casing, and a battery assisting system.

In another preferred embodiment, the electrolyte is a liquid electrolyte (electrolyte) or a polymer electrolyte. According to a fourth aspect of the present invention, a method for preparing a positive electrode of a lithium ion battery, comprising the steps of: bonding or coating a positive electrode film according to the first aspect of the present invention to a current collector, thereby preparing a positive electrode of a lithium ion battery .

According to a fifth aspect of the invention, there is provided the use of the positive electrode film for a lithium battery according to the first aspect of the invention, which is used for preparing a positive electrode of a lithium battery or for preparing a lithium battery.

According to a sixth aspect of the present invention, a method for compensating for irreversible capacity loss of a negative electrode of a lithium ion battery or reducing lithium ion loss of a lithium ion battery is provided, comprising the steps of: adding a lithium ion supplement to a positive electrode of the lithium ion battery.

In another preferred embodiment, the lithium ion extender comprises: a lithium oxygen compound, a lithium salt, a mercaptolithium compound, or a combination thereof;

In another preferred embodiment, the adding comprises: preliminarily mixing the lithium ion supplement in the lithium intercalation transition metal oxide positive electrode material or the conductive agent, or coating the surface of the positive electrode of the lithium ion battery.

In another preferred embodiment, the method further includes compensating for the loss of lithium ions on the surface of the negative electrode of the lithium battery to form a loss of the SEI film, thereby compensating for the irreversible capacity loss of the negative electrode of the lithium ion battery or reducing the lithium ion loss of the lithium ion battery.

It is to be understood that within the scope of the present invention, the various technical features of the present invention and the technical features specifically described hereinafter (as in the embodiments) may be combined with each other to constitute a new or preferred technical solution. Due to space limitations, we will not repeat them here. DRAWINGS

Figure 1 is the cyclic voltammogram of lithium battery 2 (half-cell), as shown in the figure, in the cycle of lithium battery 2 On the volt-ampere curve, it was found that an oxidation peak appeared at about 4. 4V, indicating that lithium peroxide decomposes at 4. 4V, which decomposes to produce lithium ions, which can compensate for lithium ion loss in the cathode material and electrolyte.

Figure 2 shows the cyclic volt-ampere curve of a comparative lithium battery C2 (half-cell). As can be seen, at about 4. 4V, no oxidation peak appears.

Figure 3 is the first charge and discharge curve of the lithium battery 2, as shown in the figure, the lithium peroxide decomposition platform appears around 4. 4V, indicating that the lithium peroxide is decomposed at 4. 4V, and the lithium ion generated by the decomposition can make up the cathode material. And lithium ion loss in the electrolyte.

Figure 4 shows the first charge-discharge curve of the lithium battery C2. As can be seen, there is no lithium peroxide decomposition platform at around 4. 4V.

Fig. 5 shows the charge and discharge curves of the lithium battery 3 and the comparative lithium battery C3 (full battery). As can be seen, the discharge capacity of the lithium battery 3 is increased by about 10% compared to the lithium battery C3.

detailed description

After extensive and intensive research, the inventors discovered for the first time that the addition of a lithium ion supplement to a lithium ion positive electrode can compensate for the lithium ion loss of the SEI film formed on the surface of the negative electrode, and the decomposition product thereof does not substantially affect the performance of the lithium ion battery. Improve the reversible charge and discharge capacity of lithium ion batteries and improve the electrochemical performance of lithium ion batteries. The present invention has been completed on this basis. Lithium Ion Battery

As used herein, the term "lithium ion battery" means a secondary battery composed of two compounds capable of reversibly intercalating and deintercalating lithium ions as a positive and negative electrode, respectively.

When the battery is charged, lithium ions are deintercalated from the positive electrode and embedded in the negative electrode, and vice versa when discharging. The positive electrode of the lithium ion battery is in a lithium intercalated state prior to assembly. Usually, a lithium-intercalation transition metal oxide having good stability is selected as a positive electrode material.

In the present invention, the material of the negative electrode is not particularly limited, and may be various materials having a potential close to the lithium potential and intercalable with a lithium compound, and representative examples include, but are not limited to: natural graphite, synthetic graphite, carbon fiber, intermediate The phase ball carbon and the like and the metal oxide include Sn0, Sn0 ₂ , tin composite oxide and the like.

In the present invention, the electrolyte is not particularly limited and may be a liquid electrolyte (electrolyte) or a polymer electrolyte. Representative examples include, but are not limited to, a mixed solvent system of sulfhydryl carbonates such as ethylene carbonate (EC), propylene carbonate (PC), and low viscosity diethyl carbonate (DEC) using LiPF ₆ . Lithium ion supplement

As used herein, the terms "lithium ion extender" and "lithium ion additive" may be used interchangeably, and refer to a lithium battery additive for supplementing lithium ions applied to a positive electrode of a lithium battery.

The lithium ion replenishing agent which can be used in the present invention is not particularly limited, and may be any lithium ion replenishing agent having a decomposition potential lower than the oxidative decomposition potential of the electrolytic solution and higher than the discharge cutoff potential of the positive electrode of the battery.

Among the lithium-containing substances that can decompose and provide Li ⁺ as a lithium ion supplement, the lithium ion content is the highest in lithium. While the stability of lithium is higher than that of the simple substance, the preferred lithium ion supplement is an oxidized lithium ion compound.

The decomposition potential of the lithium ion replenishing agent usable in the present invention should be lower than the oxidative decomposition potential of the electrolyte and higher than the discharge cutoff potential of the positive electrode of the battery.

Commonly used lithium ion supplements are selected from:

Lithium-containing inorganics: lithium oxide, lithium peroxide, lithium superoxide, lithium hydride, lithium fluoride, lithium nitride, lithium sulfide, aluminum lithium alloy;

Lithium-containing organics: lithium methoxide, lithium ethoxide, lithium isopropoxide, ethyl lithium, isopropyl lithium, butyl lithium, lithium benzene hexaoxide.

The lithium ion extender which can be used in the present invention is preferably: lithium peroxide, lithium superoxide, lithium nitride, lithium sulfide, aluminum lithium alloy, lithium methoxide, lithium ethoxide, lithium isopropoxide, ethyl lithium, isopropyl Lithium, butyl lithium; more preferably, lithium peroxide, lithium superoxide, lithium nitride.

One or more of them are added to the positive electrode of the lithium ion battery by mixing the lithium ion supplement in advance in the positive electrode material or the conductive agent, or coating the surface of the dried positive electrode. During the first charging of the lithium battery, the lithium ion supplement will decompose and release lithium ions, which can compensate for the lithium ion loss of the SEI film formed on the surface of the negative electrode, compensate the lithium ion loss in the positive electrode material and the electrolyte, and the other decomposition products are basically not Affecting the performance of lithium ion batteries, thereby significantly improving the reversible charge and discharge capacity of lithium ion batteries, and improving the electrochemical performance of lithium ion batteries. Moreover, the lithium ion supplement used in the invention is chemically stable, is not easily decomposed in air, has low requirements on the process flow and environment, and has low production cost. Lithium battery positive film and preparation thereof

Lithium battery positive film

The invention provides a lithium battery positive film, comprising:

(i) a lithium intercalation transition metal oxide cathode material;

(ii) a lithium ion extender doped into the positive electrode material or the conductive agent and/or applied to the surface of the positive electrode of the lithium ion battery; (iii) Conductive agents and binders.

The lithium intercalation transition metal oxide cathode material is selected from the group consisting of lithium cobaltate, lithium nickelate, lithium nickel cobaltate, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminate, lithium manganate, lithium iron phosphate, Lithium manganese phosphate, lithium vanadium phosphate, or a combination thereof.

The lithium ion supplement includes: a lithium oxygen compound, a lithium salt, a mercapto lithium compound, or a combination thereof; wherein the lithium oxygen compound comprises: lithium oxide, lithium peroxide, lithium superoxide, or a combination thereof; The mercaptolithium compound comprises: lithium methoxide, lithium ethoxide, lithium isopropoxide, ethyl lithium, isopropyl lithium, butyl lithium or a combination thereof;

The lithium ion extender is in a solid state.

The conductive agent includes carbon black, graphite, carbon nanotubes, graphene, and the like.

The binder comprises PVDF, PTFE, CMC, SBR, etc., wherein PVDF is polyvinylidene fluoride, PTFE is polytetrafluoroethylene, CMC is carboxymethyl cellulose, and SBR is a copolymer of styrene and butadiene. (styrene-butadiene rubber).

The positive electrode film further contains a current collector aluminum foil.

The mass percentage of the lithium ion-containing transition metal oxide cathode material is 0.5 to 10%, more preferably 1 to 3%.

The lithium ion supplement provided by the present invention may be used in advance in a positive electrode material or a conductive agent, or may be applied to a surface of a dried lithium ion battery positive electrode. Preparation

The method of preparing the positive electrode film for a lithium battery of the present invention may be carried out by mixing a lithium ion extender into a positive electrode material or slurry of a lithium battery and/or applying it to the positive electrode of the battery after preparation of the positive electrode of the conventional lithium battery. Specifically, the preparation methods generally used include the following three types:

(al) providing a positive electrode material slurry containing a lithium intercalation transition metal oxide positive electrode material, a lithium ion replenishing agent, and a conductive agent and a binder; and vacuuming the slurry after coating the tablet Dry film is made into a positive film; or

(a2) adding a lithium ion extender and a conductive agent in advance by ball milling, adding a lithium intercalation transition metal oxide positive electrode material and a binder, and also forming a positive electrode film by vacuum drying after coating the tablet; or

(a3) A lithium ion supplement is applied to the surface of the positive electrode of the dried lithium ion battery to form a lithium battery positive film containing the lithium ion replenisher. Battery positive

The positive electrode of the battery of the present invention contains the lithium ion supplement of the present invention;

The battery positive electrode of the present invention further contains a conductive agent and a binder, wherein the conductive agent is carbon black, graphite, carbon nanotubes, graphene, etc.; the binder is PVDF, PTFE, CMC, SBR, etc.; The current collector is aluminum foil.

A preferred method of preparation comprises the steps of:

The cathode material is uniformly mixed with a lithium ion supplement, a conductive agent, and a binder in a solution (such as nitrogen methylpyrrolidone (匪P)) to adjust a mass ratio of a suitable lithium ion supplement and a cathode material, and a mass ratio of the positive electrode material, the acetylene black, and the binder, and then coating the tablet on the aluminum foil to prepare a positive electrode; or

The positive electrode film of the present invention is bonded to a current collector to prepare a positive electrode of a lithium ion battery.

5〜10%。 The mass percentage of the positive electrode material is 0. 5~10%. The beneficial effects of the invention:

1. Increasing the reversible charge and discharge capacity of a lithium battery: The lithium ion positive electrode of the lithium battery of the present invention is added with a lithium ion supplement, which can decompose and release lithium ions during the first charging of the lithium battery, and can compensate for the lithium ion forming the SEI film on the surface of the negative electrode. Loss, compensation for lithium ion loss in the positive electrode material and electrolyte, while other decomposition products do not substantially affect the performance of the lithium ion battery, thereby significantly improving the reversible charge and discharge capacity of the lithium ion battery, and improving the electrochemical performance of the lithium ion battery.

2. The lithium ion supplement is chemically stable, and the preparation cost of the positive electrode film is low: the lithium ion supplement used in the invention is a lithium-containing inorganic or organic compound in an oxidized state, which is more stable than the reduced state additive in the conventional technology, and the battery preparation process and The process environment requirements are low, thereby reducing the cost of preparation. The invention is further illustrated below in conjunction with specific embodiments. It is to be understood that the examples are merely illustrative of the invention and are not intended to limit the scope of the invention. The experimental methods in the following examples which do not specify the specific conditions are usually carried out according to conventional conditions or according to the conditions recommended by the manufacturer. Example 1 Preparation of Battery Positive Electrode 1

Commercially available lithium ion battery cathode material lithium iron phosphate and lithium ion supplement lithium peroxide, conductive agent acetylene black, and binder polyvinylidene fluoride (PVDF) in nitrogen methylpyrrolidone (匪P) solution Evenly mixed The mass of the added lithium peroxide is 1% of the mass of the lithium iron phosphate of the positive electrode material, and the mass ratio of the positive electrode material, the acetylene black and the binder is 85:10:5, respectively, and then the tablet is coated on the aluminum foil to prepare the positive electrode of the battery. 1. Example 2 Preparation of Lithium Battery 2 (Half Battery)

The positive electrode of the battery 1 was made of a lithium metal plate as a positive electrode, a solution of 1 mol/L of lithium hexafluorophosphate of ethylene carbonate and dimethyl carbonate was used as an electrolyte, and 20 μm of polyethylene was used as a separator to assemble a CR2032 type lithium coin battery. Example 3 Preparation of Lithium Battery 3 (Full Battery)

The battery positive electrode 1, graphite as the negative electrode, lmol/L lithium hexafluorophosphate carbonate solution and dimethyl carbonate solution as the electrolyte, 20 micron thick polyethylene as the separator, assembled into a 18650 cylindrical lithium battery 3 o 1 Comparison of battery positive C1 preparation

The commercial lithium ion battery cathode material lithium iron phosphate is uniformly mixed with the conductive agent acetylene black and the binder polyvinylidene fluoride (PVDF) in the solution of nitrogen methylpyrrolidone (匪P), the positive electrode material, acetylene black and The mass ratio of the binder was 85:10:5, respectively, and then the tablet was coated on an aluminum foil to prepare a positive electrode Cl of the comparative battery. Comparative Example 2 Preparation of comparative lithium battery C2 (half battery)

The preparation method was the same as in Example 2 except that the positive electrode C1 of the battery was replaced with the positive electrode C1 of the battery.

Assembled into a CR2032 button lithium battery C2. Comparative Example 3 Preparation of comparative lithium battery C3 (full battery)

The preparation method was the same as in Example 3 except that the positive electrode C1 of the battery was replaced with the positive electrode C1 of the battery.

Assembled into a 18650 lithium battery C3. Example 4 Electrochemical performance of lithium battery 2 (half-cell) and comparative lithium battery C2 (half-cell) In this example, electrochemical performance tests were carried out by a conventional method using commercially available equipment, and the test methods were as follows:

A lithium battery 2 and a comparative lithium battery C2 are respectively on the electrochemical workstation, in the range of 2. 0-4. 75V, scanning from the positive electrode of the battery to the negative electrode of the battery at a speed of 0.01 mV / s; B. The lithium battery 2 and the comparative lithium battery C2 were respectively subjected to a charge and discharge test on the charge and discharge test system, and the battery was charged and discharged with a constant current of 5 mA/g in a voltage range of 2. 0-4. 4V. Example 5 Electrochemical performance of lithium battery 3 (full battery) and comparative lithium battery C3 (full battery) The 18650 type lithium battery 3 and the comparative lithium battery C3 were subjected to charge and discharge tests on a charge and discharge test system. The battery was subjected to a charge and discharge test with a constant current of 5 mA/g in a voltage range of 2.4-4. 4V.

Result:

The test results of lithium battery 2 and comparative lithium battery C2 (half battery) are shown in Figures 1, 2, 3 and 4. The test results of lithium battery 3 and comparative lithium battery C3 (full battery) are shown in Figure 5:

(1) The decomposition peak of the lithium ion supplement is shown in the cyclic voltammetry curve of the lithium battery 1 after the addition of a specific lithium ion supplement, indicating that the lithium peroxide occurred at 4. 4V. break down.

On the cyclic voltammetry curve of the lithium battery C2, there is no oxidation peak at about 4. 4V (see Figure 2), indicating that no lithium ion decomposition occurs; the results show that: the added lithium ion supplement lithium peroxide can be decomposed Lithium ions can compensate for lithium ion loss in the cathode material and electrolyte.

(2) On the first charge and discharge curve of the lithium battery 2, it was found that a lithium peroxide decomposition platform appeared around 4. 4V. (See Figure 3); On the first charge-discharge curve of the lithium battery C2, no lithium peroxide decomposition platform was found (see Figure 4); the results showed that: lithium peroxide decomposed at 4. 4V, and the lithium produced by its decomposition Ions can compensate for lithium ion loss in the cathode material and electrolyte.

(3) Comparing the charge and discharge curves of the 18650 lithium battery 3 and the comparative lithium battery C3 (full battery) (see Figure 5), it is found that the lithium battery 3 has a discharge capacity of 1426 mAh after the addition of the lithium ion supplement. The comparative lithium battery C3 without the lithium ion supplement was increased by about 10%. The results show that the lithium ion supplement can decompose and release lithium ions during the first charge, which can compensate for the lithium ion loss of the SEI film formed on the surface of the negative electrode, compensate the lithium ion loss in the positive electrode material and the electrolyte, and thus significantly improve the reversibility of the lithium ion battery. Discharge

Example 6

Preparation of lithium battery (full battery) according to the method of Examples 1-3 4, 5, 6, Preparation of lithium batteries (full battery) without lithium ion supplements C4, C5, C6 according to the method of Comparative Examples 1-3, and The charge and discharge capacity test was carried out in accordance with Example 5. The preparation parameters and test results are shown in Table 1. Table 1

As can be seen from Table 1, after the lithium ion supplement was added to the positive electrode of the lithium battery, the charge and discharge capacity of all the batteries was increased by more than 10% compared with the lithium battery without the lithium ion supplement. All documents mentioned in the present application are hereby incorporated by reference in their entirety in their entireties in the the the the the the the the the In addition, it is to be understood that various modifications and changes may be made by those skilled in the art in the form of the appended claims.

Claims

Rights request

A positive electrode film for a lithium battery, characterized in that: the positive electrode film comprises:

(i) a lithium intercalation transition metal oxide cathode material;

(iii) Conductive agents and binders.

The lithium battery positive electrode film according to claim 1, wherein the lithium ion replenishing agent comprises: a lithium oxygen compound, a lithium salt, a mercapto lithium compound, or a combination thereof.

3. The lithium ion extender according to claim 2, wherein

The lithium oxygen compound comprises: lithium oxide, lithium peroxide, lithium superoxide, or a combination thereof; the lithium-based lithium compound comprises: lithium methoxide, lithium ethoxide, lithium isopropoxide, ethyl lithium, isopropyl Lithium, butyl lithium or a combination thereof;

5〜10%更优选为1。 The lithium ion-filled metal oxide cathode material is 0. 5~10%, more preferably 1 ~3%.

A method of preparing a positive electrode film for a lithium battery according to claim 1, wherein the method comprises: (al) providing a slurry of a positive electrode material, the slurry containing a lithium intercalation transition metal oxide positive electrode a material, a lithium ion extender, and a conductive agent and a binder; and preparing the positive electrode film by vacuum drying the coated slurry; or

A lithium ion battery comprising the battery positive electrode membrane according to claim 1.

A method of producing a positive electrode of a lithium ion battery, comprising the steps of: bonding or coating a positive electrode film according to claim 1 to a current collector, thereby producing a positive electrode of a lithium ion battery.

A use of a positive electrode film for a lithium battery according to claim 1, which is used for preparing a lithium battery positive electrode or for preparing a lithium battery.

A method for compensating for irreversible capacity loss of a negative electrode of a lithium ion battery or for reducing lithium ion loss of a lithium ion battery, comprising the steps of: adding a lithium ion supplement to a positive electrode of the lithium ion battery.

10. The method according to claim 9, wherein the method further comprises compensating for the loss of lithium ions on the surface of the negative electrode of the lithium battery to form a solid electrolyte film (SEI film), thereby compensating for the irreversible capacity loss of the negative electrode of the lithium ion battery or Reduce lithium ion loss in lithium-ion batteries.