Positive electrode material, preparation method and application

Abstract

The invention discloses a positive electrode material, a preparation method and application, the positive electrode material comprises a matrix and lithium titanate coated on part of the surface of the matrix, and the matrix is aluminum-doped lithium cobalt oxide. According to the positive electrode material disclosed by the invention, an aluminum-doped lithium cobalt oxide material (Al-LiCoO2) is taken as a matrix, and the matrix is coated and modified by adopting lithium titanate, so that the interface stability of the material is remarkably improved. Specifically, the surface of the substrate is not completely covered by lithium titanate, the surface, not covered by lithium titanate, of the substrate is exposed outside, and the surface can make contact with electrolyte in the electrochemical cycle process to generate AlF3, so that the exposed surface of the substrate is covered by AlF3; the composite coating layer formed by the lithium titanate and the AlF3 can effectively inhibit the continuous reaction between the positive electrode material and the electrolyte, so that the positive electrode material has relatively high interface stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium ion battery cathode materials, in particular to a cathode material, a preparation method and application. BACKGROUND

[0002] In the traditional liquid lithium ion battery system, one of the core technical paths to improve the energy density lies in improving the charging cutoff voltage of the battery. This technical means can effectively enhance the deintercalation degree of lithium ions from the cathode material, thereby significantly improving the energy output efficiency per unit mass or volume of the cathode material. However, the increase of the charging cutoff voltage will also cause serious challenges to the bulk structure and surface interface stability of the layered lithium ion battery cathode material.

[0003] Taking a typical cathode material lithium cobalt oxide (LiCoO2, LCO) as an example, its charging process is accompanied by significant lattice anisotropic deformation. This non-uniform deformation will cause local stress concentration in the material particle, and eventually lead to mechanical cracking of the particle. More importantly, with the increase of the working voltage, the activity of lattice oxygen will be exponentially enhanced, which may induce the oxygen precipitation reaction of the cathode material. This phenomenon not only causes irreversible damage to the cathode crystal structure, but also seriously threatens the safety performance of the battery system. In addition, the high-voltage environment will also promote the formation of high-oxidation-state Co 4 ions, which will continuously react with the electrolyte, thereby causing a series of problems such as active material loss, interface impedance surge, and accelerated performance degradation of the battery. Therefore, the development of a new cathode material with stable bulk structure has become a key scientific basis for breaking through the high-voltage liquid battery technology.

[0004] In view of this, the present application is proposed. SUMMARY

[0005] The purpose of the present application is to provide a cathode material, a preparation method and application, which overcomes the problem of poor interface stability of lithium cobalt oxide cathode material in a high-voltage environment.

[0006] The present application is implemented as follows:

[0007] In a first aspect, the present application provides a cathode material, comprising a substrate and lithium titanate coated on part of the surface of the substrate, wherein the substrate is aluminum-doped lithium cobalt oxide.

[0008] In an optional embodiment, the mass fraction of lithium titanate in the cathode material is 0.05%-0.3%.

[0009] In an optional embodiment, the content of aluminum in the substrate is 2000ppm-8000ppm.

[0010] In an optional embodiment, the D50 of the substrate is 15-20 μm.

[0011] In a second aspect, the present application provides a preparation method of the positive electrode material according to any one of the preceding embodiments, comprising:

[0012] coating, coating the lithium titanate powder on the surface of the substrate to obtain a coated material;

[0013] sintering, sintering the coated material to obtain the positive electrode material.

[0014] In a third aspect, the present application provides a preparation method of the positive electrode material according to the preceding embodiments, wherein the D50 of the lithium titanate powder is 200-250 nm.

[0015] and / or, the coating step adopts a high-speed solid-phase method;

[0016] and / or, the coating is performed in a solid-phase coating machine, and parameters of the solid-phase coating machine in the coating step are set to 4500-5500 rpm and a time of 18-22 min;

[0017] and / or, in the coated material, the lithium titanate is attached to the surface of the substrate in a point-like discrete manner.

[0018] In a fourth aspect, the present application provides a preparation method of the positive electrode material according to the preceding embodiments, wherein the sintering temperature is 750-850 ℃, and the sintering time is 5-7 h.

[0019] and / or, the preparation method of the lithium titanate powder comprises:

[0020] calcining a mixture comprising titanium dioxide and lithium hydroxide to obtain a calcined material;

[0021] crushing the calcined material to obtain the lithium titanate powder.

[0022] In a fifth aspect, the present application provides a preparation method of the positive electrode material according to the preceding embodiments, wherein the calcining temperature is 700-800 ℃, and the calcining time is 24-26 h.

[0023] and / or, the crushing is performed in a sand milling manner, a liquid additive is added to obtain a sand milling slurry in the sand milling step, the solid content of the sand milling slurry is 25-35%, and the sand milling slurry is dried after sand milling to obtain the lithium titanate powder.

[0024] In a sixth aspect, the present application provides a pole piece comprising the positive electrode material according to any one of the preceding embodiments.

[0025] In a seventh aspect, the present application provides a battery comprising the tab and the fluorine-containing electrolyte as described in the foregoing embodiments.

[0026] The present application has the following beneficial effects:

[0027] The positive electrode material of the present application takes an aluminum-doped lithium cobalt oxide material (Al-LiCoO2) as a substrate, and uses lithium titanate (Li4Ti5O 12 ) to modify the substrate by coating, so as to significantly improve the interface stability of the material. Specifically, the surface of the substrate is not completely covered by lithium titanate, and the surface of the substrate not covered by lithium titanate is exposed, which will be in contact with the electrolyte during the electrochemical cycle, generating AlF3, so that the exposed surface of the substrate is covered by AlF3, and the composite coating layer formed by lithium titanate and AlF3 can effectively inhibit the continuous reaction between the positive electrode material and the electrolyte, so that the positive electrode material of the present application has high interface stability. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0029] Figure 1 SEM images of the materials involved in Example 1 (a is aluminum-doped lithium cobalt oxide; b is coated material; c is 0.16% LTO@LCO-800; d is lithium titanate powder). DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described clearly and completely. The specific conditions are not specified in the embodiments, which are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not specified by the manufacturer, which are all conventional products that can be purchased on the market.

[0031] The present application provides a positive electrode material, which comprises a substrate and lithium titanate coated on part of the surface of the substrate, and the substrate is aluminum-doped lithium cobalt oxide.

[0032] The positive electrode material of the present application takes an aluminum-doped lithium cobalt oxide material (Al-LiCoO2) as a substrate, and uses lithium titanate to modify the substrate by coating, so as to significantly improve the interface stability of the material. Specifically, on the one hand, Al 3+ and Co 3+The ionic radius of the two materials is basically the same, and a solid solution can be formed in a larger range. After aluminum doping, the structure of the positive electrode material can be stabilized, which is beneficial to improving the rate capability and capacity, and improving the cycle performance. On the other hand, the surface of the substrate in the present application is not completely covered by lithium titanate. The surface of the substrate not covered by lithium titanate is exposed, and will come into contact with the electrolyte during the electrochemical cycle to generate AlF3, so that the exposed surface of the substrate is covered with AlF3. The composite coating layer formed by lithium titanate and AlF3 can effectively inhibit the continuous reaction between the positive electrode material and the electrolyte, so that the positive electrode material in the present application has a higher interface stability.

[0033] In an optional embodiment, the mass fraction of lithium titanate in the positive electrode material is 0.05%-0.3%.

[0034] The mass fraction of lithium titanate in the positive electrode material can significantly improve the interfacial stability of the positive electrode material within the above range. If the mass fraction of lithium titanate in the positive electrode material is too low, the effect of improving the interfacial stability of the positive electrode material is not obvious; if the mass fraction of lithium titanate is too high, it may cause the ratio of the lithium titanate coating layer and the AlF3 coating layer in the composite coating layer formed during the electrochemical cycle to change, which will lead to a reduction in the effect of improving the interfacial stability of the positive electrode material.

[0035] In an optional embodiment, the aluminum content in the matrix is ​​2000 ppm-8000 ppm.

[0036] The mass fraction of aluminum doped in the matrix within the above range can form an appropriate amount of AlF3 coating layer during the electrochemical cycle, so that the ratio of the lithium titanate coating layer and the AlF3 coating layer in the composite coating layer is appropriate, which is more conducive to improving the interface stability of the positive electrode material.

[0037] In an optional embodiment, the D50 of the substrate is 15 μm-20 μm.

[0038] A substrate D50 within the above range is beneficial for obtaining a positive electrode material with an appropriate ratio of lithium titanate to AlF3 coating layers and an appropriate thickness. Under the condition that the mass fraction of lithium titanate in the positive electrode material is the same, if the substrate D50 is too large, the specific surface area is too small, and the lithium titanate coating layer has an excessively large coverage area or is too thick. Conversely, if the substrate D50 is too small, the specific surface area is too large, and the lithium titanate coating layer has an excessively small coverage area or is too thin. Therefore, whether the substrate D50 is too large or too small, the effect of improving the interfacial stability of the positive electrode material is reduced.

[0039] An embodiment of the present invention further provides a method for preparing the positive electrode material according to any one of the aforementioned embodiments, comprising:

[0040] Coating, coating the lithium titanate powder on the surface of the substrate to obtain a coating material;

[0041] sintering the coating material to obtain the positive electrode material.

[0042] The coating step allows the lithium titanate powder to adhere to part of the surface of the substrate, and sintering is conducive to improving the bonding strength between the lithium titanate and the substrate and improving the uniformity of the distribution of the lithium titanate on the surface of the substrate. Through the coating and sintering steps, the uniformity and stability of the coating can be improved, thereby more conducive to improving the interface stability of the positive electrode material and improving the high-voltage electrical performance of the positive electrode material.

[0043] In an optional embodiment, the D50 of the lithium titanate powder is 200 nm-250 nm.

[0044] The decrease of the D50 of the lithium titanate powder is conducive to the uniform distribution of the lithium titanate powder on the substrate, and further conducive to improving the uniformity of the lithium titanate coating.

[0045] In an optional embodiment, the coating step adopts a high-speed solid-phase method.

[0046] The solid-phase coating method has the advantages of simplicity, high efficiency and easy scale-up production, but it has certain limitations, i.e., the uniformity of the coating is relatively poor. In combination with the regulation of the mass fraction of the lithium titanate in the positive electrode material of the application, part of the surface of the substrate can be exposed and not coated with the lithium titanate, which is conducive to the generation of AlF3 in the process of electrochemical cycling, and a composite coating layer of the lithium titanate and AlF3 coated on the surface of the substrate is obtained.

[0047] In an optional embodiment, the coating is performed in a solid-phase coating machine, and the parameters of the solid-phase coating machine in the coating step are set to 4500 rpm-5500 rpm and the time is 18 min-22 min.

[0048] Under this condition, the aluminum-doped lithium cobalt oxide particles can remain intact, and the surface of the substrate is relatively smooth and discrete with the lithium titanate nanoparticles. If the time is too long or the rotation speed is too high, the substrate may be damaged, such as pits, even cracks or breakage. If the time is too short or the rotation speed is too low, the uniformity of the coating may be reduced or the production efficiency may be reduced, and the phenomenon of partial agglomeration of the lithium titanate nanoparticles on the surface of the substrate and excessive bare area of the substrate may occur.

[0049] In an optional embodiment, in the coating material, the lithium titanate is attached to the surface of the substrate in a point-like discrete manner.

[0050] With the impact, extrusion and shearing action of the high-speed solid-phase method, the nano lithium titanate powder can be coated on the surface of the substrate in a point-like discrete manner, which is conducive to the uniform coating of the lithium titanate on the surface of the substrate in the positive electrode material.

[0051] In an optional embodiment, the sintering temperature is 750-850℃, and the time is 5-7h.

[0052] The calcination process can make the coating layer of lithium titanate more continuous and uniform in thickness, so that most of the substrate surface is wrapped by the coating layer of lithium titanate.

[0053] In an optional embodiment, the preparation method of the lithium titanate powder comprises:

[0054] The mixture comprising titanium dioxide and lithium hydroxide is calcined to obtain a calcined material;

[0055] The calcined material is crushed to obtain the lithium titanate powder.

[0056] In an optional embodiment, the calcination temperature is 700-800℃, and the calcination time is 24-26h, which is beneficial to obtain lithium titanate with less lattice defects and high purity.

[0057] In an optional embodiment, the crushing is performed by sand milling, and a liquid additive is added in the sand milling step to obtain a sand milling slurry, the solid content of the sand milling slurry is 25-35%, and the sand milling slurry is dried after sand milling to obtain the lithium titanate powder, and the sand milling method is beneficial to obtain nano lithium titanate powder with small particles.

[0058] The embodiment of the present application also provides a pole piece comprising the positive electrode material according to any one of the preceding embodiments.

[0059] The embodiment of the present application also provides a battery comprising the pole piece according to the preceding embodiment and a fluorine-containing electrolyte.

[0060] The features and performances of the present application are further described in detail below in combination with examples.

[0061] Example 1

[0062] The embodiment provides a preparation method of a positive electrode material, which specifically comprises the following steps:

[0063] Preparation of lithium titanate powder: TiO2 and LiOH are mixed by a solid phase method, and then calcined at 750℃ for 25h in a muffle furnace to obtain a calcined material. Subsequently, deionized water is mixed with the calcined material, and a sand mill is used to perform sand milling treatment on the calcined material under the condition of 30% solid content for 3h to obtain lithium titanate powder with D50 reduced to 227nm, and the SEM image is shown in Figure 1 d.

[0064] Coating: the prepared lithium titanate powder is coated with aluminum-doped lithium cobaltate (Al-LiCoO2, the SEM image is shown in Figure 1b, D50 is 17.57 μm, and the aluminum doping amount is 4000 ppm) to obtain a mixed powder, the mass fraction of lithium titanate in the mixed powder is 0.16 wt%, and the mixed powder is added to a solid phase coating machine for solid phase coating. The parameters of the solid phase coating machine are set to a speed of 5000 rpm and a time of 20 min to obtain a coating material in which lithium titanate is attached to the surface of the substrate in a discrete point-like manner. The SEM image is shown as follows Figure 1 As shown in b.

[0065] Sintering: The coating material was placed in a muffle furnace and sintered at 800°C for 6 hours to obtain the positive electrode material, which was recorded as 0.16% LTO@LCO-800. The SEM image is shown as follows: Figure 1 As shown in c.

[0066] Example 2

[0067] This embodiment provides a method for preparing a positive electrode material. The only difference from Example 1 is that in the coating step, the mass fraction of lithium titanate in the mixed powder is 0.08 wt %. The positive electrode material obtained in this embodiment is recorded as 0.08% LTO@LCO-800.

[0068] Example 3

[0069] This embodiment provides a method for preparing a positive electrode material. The only difference from Example 1 is that in the coating step, the mass fraction of lithium titanate in the mixed powder is 0.24 wt %. The positive electrode material obtained in this embodiment is recorded as 0.24% LTO@LCO-800.

[0070] Example 4

[0071] This embodiment provides a method for preparing a positive electrode material, which differs from Example 1 only in that, in the coating step, the rotation speed of the solid phase coating machine is 6000 rpm.

[0072] Example 5

[0073] This embodiment provides a method for preparing a positive electrode material, which differs from Example 1 only in that, in the coating step, the coating time of the solid phase coating machine is extended to 30 minutes.

[0074] Comparative Example 1

[0075] This comparative example provides an aluminum-doped lithium cobalt oxide (Al-LiCoO2) as a positive electrode material without coating.

[0076] Comparative Example 2

[0077] This comparative example provides a method for preparing a positive electrode material, which differs from Example 1 only in that, in the coating step, the lithium cobalt oxide in the mixed powder is not doped with aluminum.

[0078] Test example:

[0079] The positive electrode materials prepared in the above embodiments and comparative examples are assembled into a battery, which specifically includes the following steps:

[0080] Positive electrode slurry preparation: Polyvinylidene fluoride (PVDF) and N-methylpyrrolidone (NMP) were mixed in a mass ratio of 1:10 to prepare a binder for later use. Using a polytetrafluoroethylene ball mill as a container, the positive electrode materials prepared in the above examples and comparative examples were mixed with the above binder and acetylene black, and an appropriate amount of NMP was added dropwise to obtain a mixture with a mass ratio of positive electrode material, PVDF, and acetylene black of 8:1:1. Zirconium balls were added to the ball mill, and the ball mill was adjusted to mix at 400 rpm for 3 hours to prepare the positive electrode slurry.

[0081] Preparation of the positive electrode sheet: The positive electrode slurry is evenly placed on a carbon-coated aluminum foil and applied to the surface of the foil using a scraper at a constant speed. The coated electrode sheet is then dried in a forced-air drying oven at 50°C for 3 hours and then transferred to a vacuum oven at 100°C for 6 hours. To increase the compaction density of the electrode sheet, the dried electrode sheet is subjected to a roller press. Finally, the rolled electrode sheet is cut into circular pieces with a diameter of 12 mm and weighed for later use.

[0082] Assembly of a button cell: Use a lithium sheet as the negative electrode and a 1M LiPF6-EC:EMC electrolyte (3:7 by volume). In a glove box, starting with the positive battery case, stack the positive electrode sheet and separator, adding an appropriate amount of electrolyte and removing any bubbles to ensure a tight fit. Next, place the lithium sheet and cover with the negative battery case. Finally, place the assembled button cell in a sealing machine and press. Remove the battery, wipe off any excess electrolyte, and set aside.

[0083] Performance test: Cycling performance tests were conducted at room temperature at 0.2C and 0.5C rates. The button cell electrode used in the test had an active material loading of approximately 12 mg cm -2 The test conditions are room temperature and the charge and discharge cut-off voltage is 2.8-4.5V vs.Li / Li + , the test results are shown in Table 1.

[0084] Table 1: Cycle retention at different rates

[0085]

[0086] According to Table 1, the positive electrode material coated with lithium titanate exhibits better cycle stability than the comparative example 1 without lithium titanate. Among them, when the coating amount in Example 2 is 0.16wt%, the 0.16wt% LTO@LCO material is 2.8-4.5V vs.Li / Li + The reversible capacity of the battery reached 160 mAh g after 100 cycles at a rate of 0.2C. -1 , the capacity retention rate is 90%. In contrast, under the same test conditions, the capacity retention rate of the uncoated LCO material in Comparative Example 1 is only 61.8%, and its reversible specific capacity is only 100 mAh g -1 . After a long cycle, the 0.16wt% LTO@LCO material still maintains a relatively stable charge and discharge platform, and the battery polarization is small. This shows that the material can maintain good electrochemical performance during the cycle. However, the capacity of the uncoated lithium titanate positive electrode material shows a trend of rapid decay. After 50 cycles, its discharge platform almost disappeared. This is mainly because without the protection of the coating layer, aluminum-doped lithium cobalt oxide will have serious interface side reactions, transition metal dissolution, and particle mechanical cracks at a high voltage of 4.5V, which leads to a rapid decline in its performance.

[0087] In Example 1, when the addition amount of lithium titanate in the positive electrode material is 0.16wt%, solid phase coating is carried out at a speed of 5000rpm for 20min. SEM observation shows that the matrix particles can remain intact, the matrix surface is relatively smooth, and many lithium titanate nanoparticles (such as Figure 1 b). This uniform coating effect helps to improve the interface stability and electrochemical performance of the material after calcination. When the speed is further increased to 6000rpm in Example 4, obvious unevenness occurs on the surface of the aluminum-doped lithium cobalt oxide substrate. This is because under higher processing power and higher speed conditions, the surface structure of the substrate is destroyed, and too high a speed causes the mechanical force on the substrate to be too large, which has an adverse effect on the microstructure of the material. In Example 5, if the speed is kept constant at 5000rpm and the processing time is extended to 30min per batch, the surface of the substrate will also be uneven, which shows that too long a processing time will also cause excessive mechanical action on the surface of the material, destroying its original structural integrity. According to Table 1, it can also be seen that the damage of the substrate causes the cycle retention rate of Examples 4 and 5 to be significantly reduced compared to Example 1. It is explained that within the scope of the coating speed and coating time defined in the present application, it is possible to achieve effective discrete coating of lithium titanate nanoparticles while ensuring the integrity and surface smoothness of the substrate particles, which is conducive to improving the interface stability of the positive electrode material and laying the foundation for subsequent electrochemical performance improvement.

[0088] Figure 1 In the figure, a-d are SEM images of the aluminum-doped lithium cobalt oxide matrix material, the coating material, the positive electrode material and the lithium titanate powder in Example 1, respectively, wherein, Figure 1 a is the initial uncoated aluminum-doped lithium cobalt oxide, and it can be seen that the surface is relatively smooth, and there are some flaky debris, which is the LCO debris caused by the airflow breaking process in the commercial synthesis process. Figure 1 d is the lithium titanate powder after spray drying. After mixing the matrix and the lithium titanate powder by high-speed solid-phase method, Figure 1 As can be seen from b, a large amount of lithium titanate powder is densely and uniformly attached to the surface of the matrix in the coating material. After the coating material is placed in a muffle furnace and sintered at 800°C for 6 hours, a positive electrode material with a relatively uniform and smooth surface is obtained, that is, the lithium titanate forms a relatively continuous coating layer on the surface of the matrix. Figure 1 b is more uniform and smooth. b is more uniform and smooth.

[0089] The D50 of the aluminum-doped lithium cobalt oxide, the lithium titanate powder and the prepared positive electrode material involved in Examples 1-3 is tested, and the results are shown in Table 2.

[0090] Table 2

[0091] Material / coating amount D50 (pm) Aluminum-doped lithium cobalt oxide 17.57 Lithium titanate powder 0.227 0.08% LTO@LCO-800 17.61 0.16% LTO@LCO-800 17.62 0.24% LTO@LCO-800 17.64

[0092] As can be seen from Table 2, the D50 of the matrix before and after coating and sintering changes little, which indicates that the integrity of the particles can be maintained during the preparation of the positive electrode material, and there is no serious particle breakage problem, which is conducive to the improvement of the interface stability of the lithium cobalt oxide positive electrode material in a high-voltage environment.

[0093] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A positive electrode material, characterized in that The invention comprises a substrate and lithium titanate coated on the surface of the substrate, wherein the substrate is aluminum-doped lithium cobaltate.

2. The positive electrode material according to claim 1, characterized in that The mass fraction of lithium titanate in the positive electrode material is 0.05%-0.3%.

3. The positive electrode material according to claim 1, characterized in that The aluminum content in the matrix is ​​2000ppm-8000ppm.

4. The positive electrode material according to claim 1, characterized in that The D50 of the substrate is 15 μm-20 μm.

5. A method for preparing the positive electrode material according to any one of claims 1 to 4, characterized in that: include: Coating, coating the lithium titanate powder on the surface of the substrate to obtain a coating material; Sintering: sintering the coating material to obtain the positive electrode material.

6. The method for preparing the positive electrode material according to claim 5, wherein: The D50 of the lithium titanate powder is 200nm-250nm; and / or, the coating step adopts a high-speed solid phase method; And / or, the coating is carried out in a solid phase coating machine, and the parameters of the solid phase coating machine in the coating step are set to 4500 rpm-5500 rpm, and the time is 18 min-22 min; And / or, in the coating material, the lithium titanate is attached to the surface of the substrate in a discrete point-like manner.

7. The method for preparing the positive electrode material according to claim 5, wherein: The sintering temperature is 750℃-850℃ and the sintering time is 5h-7h; And / or, the preparation method of the lithium titanate powder comprises: calcining a mixture comprising titanium dioxide and lithium hydroxide to obtain a calcined material; The calcined material is crushed to obtain the lithium titanate powder.

8. The method for preparing the positive electrode material according to claim 5, wherein: The calcination temperature is 700-800°C and the calcination time is 24-26 hours; And / or, the crushing is performed by sand milling, a liquid additive is added during the sand milling step to obtain a sand milling slurry, the solid content of the sand milling slurry is 25%-35%, and after sand milling, the sand milling slurry is dried to obtain the lithium titanate powder.

9. A pole piece, characterized in that: The positive electrode material comprises the positive electrode material according to any one of claims 1 to 4.

10. A battery, characterized in that: It comprises the electrode as claimed in claim 9 and a fluorine-containing electrolyte.

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