Method for evaluating high-temperature storage performance of lithium-rich manganese-based lithium ion battery

Abstract

The invention provides a method for evaluating the high-temperature storage performance of a lithium-rich manganese-based lithium ion battery, and relates to the technical field of batteries. The invention provides a method for evaluating the high-temperature storage performance of a lithium-rich manganese-based lithium ion battery. The method comprises the following steps: carrying out overcharge and discharge cycle treatment on a to-be-tested lithium-rich manganese-based lithium ion battery which is fully charged; and discharging the treated battery to 0.1-0.5 V at constant current and constant voltage, storing for 2-72 hours at 40-70 DEG C, extracting side reaction gas of the battery, and evaluating the high-temperature storage performance of the lithium-rich manganese-based lithium ion battery to be tested according to the proportion of H2 in the side reaction gas. The method is simple and convenient, the high-temperature storage performance of the lithium-rich manganese-based lithium ion battery can be quickly predicted, the result accuracy is high, manpower and material resources are greatly saved, and the research and development efficiency of the battery can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and particularly to a method for evaluating the high-temperature storage performance of lithium-rich manganese-based lithium-ion batteries. Background Art

[0002] Lithium-ion batteries have the advantages of high energy density, long cycle life, and no memory effect, and are one of the most widely used electrochemical energy storage devices. In recent years, new energy electric vehicles driven by lithium-ion batteries have been vigorously developed. However, with the gradual increase in the demand for driving range of electric vehicles, the requirement for the energy density of lithium-ion batteries has also gradually increased. As an important part of lithium-ion batteries, the cathode material directly determines the energy density of lithium-ion batteries. However, the actual specific capacity of existing commercial cathode materials is lower than 200 mAh g -1 . The energy density of lithium-ion full batteries assembled based on these cathode materials is relatively low, and it is difficult to meet the demand for greater driving range of electric vehicles.

[0003] The discharge specific capacity of lithium-rich manganese-based cathode materials is as high as 300 mAh g -1 (2 - 4.8 V), which is much higher than that of currently commercialized lithium-ion battery cathode materials, and is considered to be an ideal choice for the next generation of high-energy-density lithium-ion batteries. It is also one of the key materials for lithium-ion batteries to break through an energy density of 400 Wh kg -1 or even 500 Wh kg -1 . However, in the evaluation process of lithium-rich manganese-based lithium-ion batteries, the evaluation and testing of high-temperature storage performance are extremely time-consuming and costly, which will undoubtedly increase the investment in R & D costs and affect the R & D efficiency of new products.

[0004] In view of this, the present invention is specifically proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for evaluating the high-temperature storage performance of lithium-rich manganese-based lithium-ion batteries to solve the above technical problems.

[0006] To achieve the above purpose, the following technical solutions are specifically adopted:

[0007] In a first aspect, the present invention provides a method for evaluating the high-temperature storage performance of lithium-rich manganese-based lithium-ion batteries, including the following steps:

[0008] a. Perform overcharge and discharge cycle treatment on a fully charged lithium-rich manganese-based lithium-ion battery to be tested; the overcharge time is 5 - 60 min; the discharge is to discharge the battery at a constant current until 90% - 95% SOC;

[0009] b. The battery processed in step a is discharged at a constant current and constant voltage to 0 - 0.5V, then stored at 30 - 70°C for 2 - 72h. After that, the side reaction gas of the battery is extracted, and the high-temperature storage performance of the lithium-rich manganese-based lithium-ion battery to be tested is evaluated according to the proportion of H2 in the side reaction gas.

[0010] As a further technical solution, in step a, the overcharge current is 0.1 - 1C, the discharge current is 0.1 - 1C, and the number of cycles of the overcharge and discharge cycle treatment is 2 - 10 times.

[0011] As a further technical solution, in step b, the discharge is a constant current and constant voltage discharge at a current of 0.1 - 1C. When reaching the constant voltage section, the cut-off current in the constant voltage section is 0.001 - 0.05C.

[0012] As a further technical solution, the positive electrode sheet of the lithium-rich manganese-based lithium-ion battery includes a positive electrode current collector and a positive electrode paste layer coated on the positive electrode current collector;

[0013] The positive electrode paste layer includes a positive electrode active material, a conductive agent, a binder, and a dispersant. Among them, the mass ratio of the positive electrode active material is 93% - 97%, the mass ratio of the conductive agent is 0.5% - 3%, the mass ratio of the binder is 1% - 2.5%, and the mass ratio of the dispersant is 0.5% - 1.5%.

[0014] As a further technical solution, the positive electrode active material includes at least one of layered lithium-rich oxides (such as xLi2MnO3·(1 - x)LiTMO2, where 0.5 ≤ x ≤ 1, and TM is a transition metal such as Ni / Co / Mn), lithium manganate, or lithium iron phosphate manganese.

[0015] The conductive agent includes at least one of carbon black, carbon nanotubes, or graphene;

[0016] The binder is polyvinylidene fluoride (PVDF);

[0017] The dispersant includes at least one of polyvinylpyrrolidone (PVP) or polyvinyl butyral (PVB).

[0018] As a further technical solution, the negative electrode sheet of the lithium-rich manganese-based lithium-ion battery includes a negative electrode current collector and a negative electrode paste layer coated on the negative electrode current collector;

[0019] The negative electrode paste layer includes a negative electrode active material, a conductive agent, and a binder. Among them, the proportion of the negative electrode active material is 93 - 97%, the mass ratio of the conductive agent is 0.5% - 3.5%, and the mass ratio of the binder is 1% - 3.5%.

[0020] As a further technical solution, the negative electrode active material includes at least one of graphite or hard carbon;

[0021] The conductive agent includes at least one of carbon black, carbon nanotubes or graphene;

[0022] The binder includes at least one of carboxymethyl cellulose, polyacrylic acid or styrene-butadiene rubber latex.

[0023] As a further technical solution, the separator of the lithium-rich manganese-based lithium ion battery includes a coated separator or a ceramic separator.

[0024] As a further technical solution, the electrolyte of the lithium-rich manganese-based lithium ion battery includes a solvent, a lithium salt and an additive;

[0025] The solvent includes at least one of EC (ethylene carbonate), EMC (ethyl methyl carbonate), FEMC (fluoroethylene carbonate) or DEC (diethyl carbonate);

[0026] The lithium salt includes LiPF6 with a concentration of 0.8 - 1.2 M;

[0027] The additive includes at least one of DTD (ethylene sulfate) or MMDS (methyl methanedisulfonate), and the dosage of the additive is 0.5% wt - 4% wt.

[0028] As a further technical solution, the type of the lithium-rich manganese-based lithium ion battery includes a wound battery or a laminated battery.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. It can quickly screen the high-temperature storage performance of lithium-rich manganese-based lithium ion batteries and improve the development efficiency of new materials, new systems and new products; from the current results, it can effectively predict the trend of the battery after 56 days of storage at 60°C;

[0031] 2. It can greatly reduce the labor and material costs required for the high-temperature storage test of lithium manganese-based lithium ion batteries. Description of the Drawings

[0032] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0033] Figure 1 It is the result detected by using the method of Example 1 in Test Example 1;

[0034] Figure 2 The test results using the conventional method in Test Example 1;

[0035] Figure 3 The results detected using the method of Example 2 in Test Example 2;

[0036] Figure 4 The test results using the conventional method in Test Example 2;

[0037] Figure 5 The results detected using the method of Example 3 in Test Example 3;

[0038] Figure 6 The test results using the conventional method in Test Example 3. Specific Embodiments

[0039] The embodiments of the present invention will be described in detail below in conjunction with the embodiments and examples. However, those skilled in the art will understand that the following embodiments and examples are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention. Those not specified in specific conditions are carried out according to conventional conditions or conditions recommended by the manufacturer. Those reagents or instruments not specified in the manufacturer are all conventional products that can be obtained through commercial purchase.

[0040] In a first aspect, the present invention provides a method for evaluating the high-temperature storage performance of a lithium-rich manganese-based lithium-ion battery, comprising the following steps:

[0041] a. Subject the fully charged lithium-rich manganese-based lithium-ion battery to overcharge and discharge cycling; the overcharge time is 5 - 60 min; the discharge is to discharge the battery at a constant current until 90% - 95% SOC;

[0042] b. Discharge the battery obtained in step a at a constant current and constant voltage to 0 - 0.5 V, then store it at 30 - 70 °C for 2 - 72 h, and then extract the side reaction gas of the battery, and evaluate the high-temperature storage performance of the lithium-rich manganese-based lithium-ion battery to be tested according to the proportion of H2 in the side reaction gas.

[0043] The main mechanism of the present invention is to deposit manganese (or other transition metals) on the surface of the negative electrode by high-voltage segment oscillation of the battery in a form similar to overcharging; then, artificially decompose the SEI on the surface of the negative electrode in a form similar to over-discharging, and store the over-discharged battery at a high temperature to accelerate the occurrence of side reactions. Among them, the generation of hydrogen may be related to the spontaneous repair of the SEI film affected by the self-generated polarization after the battery is over-discharged, and this behavior is similar to the principle of SEI film repair during high-temperature storage. Therefore, the present invention can be used as a means for accelerating the evaluation of high-temperature storage.

[0044] The method for evaluating the high-temperature storage performance of the lithium-rich manganese-based lithium-ion battery provided by the present invention is simple and convenient, can quickly predict the high-temperature storage performance of the lithium-rich manganese-based lithium-ion battery, has high result accuracy, greatly saves manpower and material resources, and can effectively improve the R & D efficiency of the battery.

[0045] In some alternative embodiments, in step a, the current for overcharging can be, for example, but not limited to, 0.1C, 0.6C or 1C, preferably 0.3C, the current for discharging can be, for example, but not limited to, 0.1C, 0.6C or 1C, preferably 0.3C, and the number of cycles of the overcharging and discharging cycle treatment can be, for example, but not limited to, 2 times, 6 times or 10 times.

[0046] In some alternative embodiments, in step b, the discharging is carried out at a constant current and constant voltage with a current of 0.1-1C (preferably 0.3C). When discharging to the constant voltage section, the cut-off current in the constant voltage section is 0.001-0.05C, preferably 0.01C.

[0047] In some alternative embodiments, in step b, it is preferred to discharge the battery processed in step a at a constant current and constant voltage to 0.3V.

[0048] In some alternative embodiments, in step b, it is preferred to store the discharged battery at 60 °C for 24 h.

[0049] In some alternative embodiments, the positive electrode plate of the lithium-rich manganese-based lithium-ion battery includes a positive electrode current collector and a positive electrode paste layer coated on the positive electrode current collector;

[0050] The positive electrode paste layer includes a positive electrode active material, a conductive agent, a binder, and a dispersant. Among them, the mass ratio of the positive electrode active material can be, for example, but not limited to, 93%, 95% or 97%, the mass ratio of the conductive agent can be, for example, but not limited to, 0.5%, 1% or 3%, the mass ratio of the binder can be, for example, but not limited to, 1%, 2% or 2.5%, and the mass ratio of the dispersant is 0.5%, 1% or 1.5%.

[0051] In some alternative embodiments, the positive electrode active material includes at least one of layered lithium-rich oxides, lithium manganate, or lithium iron manganese phosphate;

[0052] The conductive agent includes at least one of carbon black, carbon nanotubes, or graphene;

[0053] The binder is polyvinylidene fluoride.

[0054] The dispersant includes at least one of polyvinylpyrrolidone or polyvinyl butyral.

[0055] In some alternative embodiments, the negative electrode sheet of the lithium-rich manganese-based lithium ion battery includes a negative electrode current collector and a negative electrode paste layer coated on the negative electrode current collector;

[0056] The negative electrode paste layer includes a negative electrode active material, a conductive agent, and a binder. For example, the proportion of the negative electrode active material can be, but is not limited to, 93%, 95%, or 97%. The mass proportion of the conductive agent can be, but is not limited to, 0.5%, 1%, or 3.5%. The mass proportion of the binder can be, but is not limited to, 1%, 2%, or 3.5%.

[0057] In some alternative embodiments, the negative electrode active material includes at least one of graphite or hard carbon;

[0058] The conductive agent includes at least one of carbon black, carbon nanotubes, or graphene;

[0059] The binder includes at least one of carboxymethyl cellulose, polyacrylic acid, or styrene-butadiene rubber latex.

[0060] In some alternative embodiments, the separator of the lithium-rich manganese-based lithium ion battery includes a gelled separator or a ceramic separator.

[0061] In some alternative embodiments, the electrolyte of the lithium-rich manganese-based lithium ion battery includes a solvent, a lithium salt, and an additive;

[0062] The solvent includes at least one of EC, EMC, FEMC, or DEC;

[0063] The lithium salt includes LiPF6, and the concentration can be, but is not limited to, 0.8 M, 1 M, or 1.2 M;

[0064] The additive includes at least one of DTD or MMDS, and the dosage of the additive can be, but is not limited to, 0.5% wt, 2% wt, or 4% wt.

[0065] In some alternative embodiments, the type of the lithium-rich manganese-based lithium ion battery includes a wound battery or a laminated battery.

[0066] The present invention will be further described below through specific embodiments. However, it should be understood that these embodiments are only used for more detailed description and should not be construed as limiting the present invention in any way.

[0067] It should be noted that in the following test examples, the component ratios are all mass ratios, and the dosage ratios are all mass percentages.

[0068] Example 1

[0069] A method for evaluating the high-temperature storage performance of a lithium-rich manganese-based lithium-ion battery, comprising the following steps:

[0070] 1. Perform overcharge and discharge cycle treatment on the fully charged lithium-rich manganese-based lithium-ion battery to be tested; wherein the overcharge time is 5 min, and the overcharge current is 1C; the discharge is to discharge the battery at a constant current until 93% SOC, and the discharge current is 1C; the number of overcharge and discharge cycle treatments is 6 times;

[0071] 2. Discharge the treated battery at a constant current of 0.1C to 0.2V under constant current and constant voltage, and the cut-off current at the constant voltage stage is 0.01C;

[0072] 3. Store the discharged battery at 60 °C for 24 h, then extract the side reaction gas of the battery, and evaluate the high-temperature storage performance of the lithium-rich manganese-based lithium-ion battery to be tested according to the proportion of H2 in the side reaction gas.

[0073] Example 2

[0074] A method for evaluating the high-temperature storage performance of a lithium-rich manganese-based lithium-ion battery, comprising the following steps:

[0075] 1. Perform overcharge and discharge cycle treatment on the fully charged lithium-rich manganese-based lithium-ion battery to be tested; wherein the overcharge time is 30 min, and the overcharge current is 0.5C; the discharge is to discharge the battery at a constant current until 90% SOC, and the discharge current is 0.5C; the number of overcharge and discharge cycle treatments is 3 times;

[0076] 2. Discharge the treated battery at a constant current of 0.2C to 0.5V under constant current and constant voltage, and the cut-off current at the constant voltage stage is 0.05C;

[0077] 3. Store the discharged battery at 40 °C for 72 h, then extract the side reaction gas of the battery, and evaluate the high-temperature storage performance of the lithium-rich manganese-based lithium-ion battery to be tested according to the proportion of H2 in the side reaction gas.

[0078] Example 3

[0079] A method for evaluating the high-temperature storage performance of a lithium-rich manganese-based lithium-ion battery, comprising the following steps:

[0080] 1. Subject the fully charged lithium-rich manganese-based lithium-ion battery to be tested to overcharge and discharge cycling; where the overcharge time is 60 min, the overcharge current is 0.1C; the discharge is to discharge the battery at a constant current until 95% SOC, and the discharge current is 0.1C; the number of overcharge and discharge cycling is 10 times;

[0081] 2. Discharge the processed battery at a constant current of 1C to 0.1V, and the cut-off current for the constant voltage section during discharge is 0.001C;

[0082] 3. Store the discharged battery at 70 °C for 2 h, then extract the side reaction gas of the battery, and evaluate the high-temperature storage performance of the lithium-rich manganese-based lithium-ion battery to be tested according to the proportion of H2 in the side reaction gas.

[0083] Test Example 1

[0084] Design 4 batteries according to the following table. Among them, the positive electrode active material of Battery 1 is lithium manganate, the positive electrode conductive agent is carbon black, the positive electrode binder is polyvinylidene fluoride, and the dispersant is polyvinylpyrrolidone; the negative electrode active material is graphite, the negative electrode conductive agent is carbon black, and the negative electrode binder is carboxymethyl cellulose;

[0085] The positive electrode active material of Battery 2 is lithium iron manganese phosphate, the positive electrode conductive agent is carbon nanotubes, the positive electrode binder is polyvinylidene fluoride, and the dispersant is polyvinyl butyral; the negative electrode active material is graphite, the negative electrode conductive agent is carbon nanotubes, and the negative electrode binder is polyacrylic acid;

[0086] The positive electrode active material of Battery 3 is LiCoO2, the positive electrode conductive agent is graphene, the positive electrode binder is polyvinylidene fluoride, and the dispersant is polyvinylpyrrolidone; the negative electrode active material is graphite, the negative electrode conductive agent is graphene, and the negative electrode binder is styrene-butadiene rubber;

[0087] The positive electrode active material of Battery 4 is 0.8Li2MnO3·0.2LiMn 0.6 Ni 0.4 O2, the positive electrode conductive agent is a mixture of carbon black, carbon nanotubes and graphene, the positive electrode binder is polyvinylidene fluoride, and the dispersant is polyvinyl butyral. The negative electrode active material is graphite, the negative electrode conductive agent is a mixture of carbon black, carbon nanotubes and graphene, and the negative electrode binder is styrene-butadiene rubber.

[0088]

[0089] The separator of the above 4 batteries uses a coated separator; the battery electrolytes are all: solvent (EC: EMC: FEMC is 25:25:50), lithium salt: 1.2M LiPF6, additives are DTD and MMDS, and the total mass ratio is 2.5%; the battery types are all laminated batteries.

[0090] The method provided in Example 1 was used to evaluate the high-temperature storage performance of the above batteries. After testing, the hydrogen content in the side reaction gas of each battery after the test was as Figure 1 shown.

[0091] The high-temperature storage performance of the above batteries was tested by a conventional method, that is, the above batteries were charged at a constant current and constant voltage of 0.2C to full charge and then placed in a 60°C incubator for storage, and 0.2C charge and discharge tests were carried out at 28 days / 56 days respectively to obtain the battery recovery rate test results as Figure 2 shown.

[0092] Comparing Figure 1 and Figure 2 it can be seen that the high-temperature storage performance of each battery is consistent with its hydrogen content, indicating that the method of the present invention can accurately predict the actual storage performance difference.

[0093] Test Example 2

[0094] A positive electrode sheet was prepared using lithium manganate as the active material, carbon black as the conductive agent, polyvinylidene fluoride as the binder, and polyvinylpyrrolidone as the dispersant; a negative electrode sheet was prepared with a mass ratio of graphite, carbon black, and styrene-butadiene rubber of 95:2.5:2.5; an electrolyte was prepared with EC, EMC, FEMC, a lithium salt, and additives (DTD and MMDS), and a single-sided coated and single-sided ceramic diaphragm was used as the battery diaphragm to prepare laminated batteries 1-3, where the compositions of the positive electrode sheet and the electrolyte are as follows:

[0095]

[0096] The method of Example 2 was used to evaluate the high-temperature storage performance of the above batteries. After testing, the hydrogen content in the side reaction gas of each battery after the test was as Figure 3 shown.

[0097] The high-temperature storage performance of the above batteries was tested by a conventional method, that is, the above batteries were respectively charged at a constant current and constant voltage of 0.2C to full charge and then placed in a 60°C incubator for storage, and 0.2C charge and discharge tests were carried out at 28 days / 56 days respectively to obtain the battery recovery rate results as Figure 4 shown.

[0098] Comparing Figure 3 and Figure 4 it can be seen that the high-temperature storage performance of each battery is consistent with its hydrogen content, indicating that the method of the present invention can accurately predict the actual storage performance difference.

[0099] Test Example 3

[0100] The positive electrode sheet is prepared with lithium manganate as the active material, carbon black as the conductive agent, polyvinylidene fluoride as the binder, and polyvinylpyrrolidone as the dispersant; the negative electrode sheet is prepared with graphite or hard carbon as the active material, carbon black as the conductive agent, and styrene-butadiene rubber as the binder; the electrolyte is: solvent (EC:EMC:FEMC is 25:25:50), lithium salt: 1.2M LiPF6, and the additives are DTD and MMDS, with a total mass ratio of 4%; a wound battery 1-4 is prepared using a coated separator as the battery separator, and the compositions of the positive and negative electrode sheets are as follows in the table:

[0101]

[0102]

[0103] The high-temperature storage performance of the above batteries was evaluated by the method of Example 3. After testing, the content of hydrogen in the side reaction gas of each battery after testing is as Figure 5 shown.

[0104] The high-temperature storage performance of the above batteries was tested by a conventional method, that is, the above batteries were respectively fully charged at a constant current and constant voltage of 0.2C and then placed in an incubator at 60°C for storage, and 0.2C charge and discharge tests were carried out at 28 days / 56 days respectively to obtain the recovery rate results of the batteries as Figure 6 shown.

[0105] Comparing Figure 5 and Figure 6 it can be seen that the high-temperature storage performance of each battery is consistent with the content of its hydrogen, indicating that the method of the present invention can accurately predict the actual storage performance difference.

[0106] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for evaluating the high temperature storage performance of lithium-rich manganese-based lithium-ion batteries, characterized in that: The following steps are involved: a. subjecting the fully charged lithium-manganese-rich lithium-ion battery to be tested to an overcharge and discharge cycle; the overcharge time is 5-60 minutes; the discharge is to discharge the battery at a constant current to 90%-95% SOC; b. Discharge the battery treated in step a at constant current and constant voltage to 0-0.5V, then store it at 30-70°C for 2-72h, extract the side reaction gas of the battery, and evaluate the high temperature storage performance of the lithium-rich manganese-based lithium-ion battery to be tested based on the proportion of H2 in the side reaction gas.

2. The method according to claim 1, characterized in that In step a, the overcharge current is 0.1-1C, the discharge current is 0.1-1C, and the number of cycles of the overcharge and discharge cycle treatment is 2-10 times.

3. The method according to claim 1, characterized in that In step b, the discharge is a constant current and constant voltage discharge with a current of 0.1-1C. When the discharge reaches the constant voltage stage, the cut-off current of the constant voltage stage is 0.001-0.05C.

4. The method according to claim 1, characterized in that: The positive electrode sheet of the lithium-rich manganese-based lithium-ion battery comprises a positive electrode current collector and a positive electrode slurry layer coated on the positive electrode current collector; The positive electrode slurry layer includes positive electrode active material, conductive agent, binder and dispersant, wherein the mass proportion of positive electrode active material is 93%-97%, the mass proportion of conductive agent is 0.5%-3%, the mass proportion of binder is 1%-2.5%, and the mass proportion of dispersant is 0.5%-1.5%.

5. The method according to claim 4, characterized in that The positive electrode active material includes at least one of layered lithium-rich oxide, lithium manganate or lithium iron manganese phosphate; The conductive agent includes at least one of carbon black, carbon nanotubes or graphene; The binder is polyvinylidene fluoride; The dispersant includes at least one of polyvinyl pyrrolidone and polyvinyl butyral.

6. The method according to claim 1, characterized in that The negative electrode sheet of the lithium-rich manganese-based lithium ion battery comprises a negative electrode current collector and a negative electrode slurry layer coated on the negative electrode current collector; The negative electrode slurry layer includes negative electrode active material, conductive agent and binder, wherein the negative electrode active material accounts for 93-97%, the conductive agent accounts for 0.5%-3.5% by mass, and the binder accounts for 1%-3.5% by mass.

7. The method according to claim 6, characterized in that The negative electrode active material includes at least one of graphite or hard carbon; The conductive agent includes at least one of carbon black, carbon nanotubes or graphene; The binder includes at least one of carboxymethyl cellulose, polyacrylic acid or styrene-butadiene rubber emulsion.

8. The method according to claim 1, characterized in that The diaphragm of the lithium-rich manganese-based lithium ion battery includes a rubber-coated diaphragm or a ceramic diaphragm.

9. The method according to claim 1, characterized in that: The electrolyte of the lithium-rich manganese-based lithium-ion battery includes a solvent, a lithium salt and an additive; The solvent includes at least one of EC, EMC, FEMC or DEC; The lithium salt includes LiPF6 with a concentration of 0.8-1.2M; The additive comprises at least one of DTD and MMDS, and the amount of the additive is 0.5%wt-4%wt.

10. The method according to claim 1, characterized in that The types of the lithium-rich manganese-based lithium-ion battery include a wound battery or a laminated battery.

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