A negative electrode slurry, a method for preparing the same, and use thereof

Abstract

The application provides a negative electrode slurry, a preparation method and use thereof. The preparation method comprises the following steps: (1) mixing a first conductive agent and a first solvent to obtain a first mixed slurry; (2) mixing a binder, a second solvent and the first mixed slurry to obtain a second mixed slurry; mixing a negative electrode active material and a second conductive agent to obtain a third mixed material; (3) mixing a part of the second mixed slurry and the third mixed material to obtain a fourth mixed slurry; (4) mixing another part of the second mixed slurry and the fourth mixed slurry, adding the second solvent and mixing again to obtain the negative electrode slurry; the first conductive agent comprises carbon nanotubes and / or graphene, and the binder comprises polyacrylic acid. The preparation method provided by the application inhibits the strong force between the PAA binder and the carbon nanotube and graphene conductive agent, solves the problems of difficult dispersion of the negative electrode slurry, excessively high viscosity and serious gelation phenomenon, and the problem of difficult processing of the electrode sheet.

Description

A negative electrode slurry, its preparation method and uses Technical Field

[0001] This invention belongs to the field of lithium-ion battery technology, and relates to a negative electrode slurry, its preparation method and application. Background Technology

[0002] Currently, the manufacturing process of lithium-ion battery electrodes involves first preparing a battery slurry, then coating the slurry onto a metal current collector, drying it, and finally bonding the active materials together with a binder onto the current collector to obtain a uniform and stable electrode, which is then used for battery manufacturing. With the diversification and scaling up of lithium-ion battery applications, especially with the advent of the new energy vehicle era, higher demands are being placed on battery range. Lithium-ion power batteries have entered a period of rapid development, moving towards higher capacity, higher energy density, and longer lifespan. Graphite, as a negative electrode active material, has a specific capacity of only 372 mAh / g, making it difficult to meet high capacity requirements. Silicon-based materials, on the other hand, have a high theoretical specific capacity (~4200 mAh / g), and their minimum capacity is several times that of graphite, making them the most promising negative electrode materials.

[0003] Silicon-based materials exhibit low conductivity, leading to high battery internal resistance and significant polarization. Besides preparing silicon-based materials with higher conductivity, a common approach is to add carbon nanotubes (CNTs), which have higher conductivity, to the slurry to mitigate this deficiency. Traditional negative electrode slurry preparation primarily uses aqueous styrene-butadiene rubber (SBR) and carboxymethyl cellulose (CMC) as binders and dispersants. However, an increasing number of battery companies are now using polyacrylic acid (PAA) binders to address issues such as the high expansion of silicon materials during charge and discharge. The problem is that adding CNTs to most PAA binder systems often presents challenges during slurry preparation, affecting the battery slurry processing performance, electrode processing performance, and battery electrical performance. The main reason is that carbon nanotubes have significant dispersion problems during the slurry preparation process, leading to agglomeration. This results in a significant increase in slurry viscosity and fineness, and a significant decrease in stability, sometimes even gelation. Poor slurry quality causes problems in electrode processing, severely affecting the electrode's film resistance, peel strength, and flexibility. Ultimately, this leads to no improvement in battery internal resistance and uneven internal polarization, resulting in poor battery performance. When applied to polyacrylic acid binder systems, most polyacrylic acid binders are mainly binary or multi-component copolymers of acrylic acid, acrylamide, acrylonitrile, and propylene esters. Different types of PAA binders have different contents of each comonomer, leading to varying degrees of damage to the carbon nanotube conductive agent dispersion system. Acrylonitrile, in particular, has strong polar groups that easily form hydrogen bonds with other polar groups. Furthermore, its π electrons easily form strong π-π conjugation with the π electrons of carbon nanotubes or graphene, resulting in stronger agglomeration of material particles in the lithium battery slurry, which is detrimental to the large-scale processing of the negative electrode slurry.

[0004] CN105406039A discloses a silicon-carbon anode slurry and its preparation method. The silicon-carbon anode slurry comprises an acrylonitrile multi-component copolymer LA-type aqueous electrode binder, carbon black Super-p conductive agent, a single-arm carbon nanotube suspension emulsion, a silicon-carbon / carbon nanotube composite anode material, and deionized water. Utilizing the good ductility of the carbon nanotube conductive agent and the acrylonitrile multi-component copolymer aqueous dispersion binder, it can withstand repeated expansion and contraction of the silicon-carbon composite anode material, thus improving the material's cycle performance.

[0005] CN109546127A discloses a silicon-carbon anode slurry and its preparation method. The silicon-carbon anode slurry contains the following components: a silicon-based / graphite mixture, a binder, single-walled carbon nanotubes, carbon black, and a coupling agent. The binder is a polyacrylic acid polymer containing carboxyl functional groups.

[0006] Both of the aforementioned documents involve the combination of PAA-type binders and carbon nanotubes. However, this combination tends to result in stronger agglomeration between material particles during homogenization, which is not conducive to the large-scale processing of negative electrode slurries.

[0007] Therefore, optimizing the negative electrode slurry without degrading the electrode processing performance is an urgent technical problem to be solved. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention aims to provide a negative electrode slurry, its preparation method, and its applications. The negative electrode slurry preparation method provided by the present invention, through the mixing sequence and the addition of a new solvent, suppresses the strong interaction between PAA-type binders and carbon nanotubes and graphene conductive agents, thus solving the problems of difficult dispersion, excessively high viscosity, and severe gelation in negative electrode slurries, which lead to slurry processing difficulties and electrode sheet processing challenges.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] In a first aspect, the present invention provides a method for preparing a negative electrode slurry, the method comprising the following steps:

[0011] (1) The first conductive agent and the first solvent are mixed to obtain a first mixed slurry;

[0012] (2) Mix the adhesive, the second solvent and the first mixed slurry from step (1) to obtain the second mixed slurry;

[0013] The negative electrode active material is mixed with the second conductive agent to obtain the third mixture;

[0014] (3) Take a portion of the second mixed slurry and mix it with the third mixed slurry to obtain the fourth mixed slurry;

[0015] (4) Take another portion of the second mixed slurry and mix it with the fourth mixed slurry to obtain the fifth mixed slurry. Add the second solvent and mix again to obtain the negative electrode slurry.

[0016] The first conductive agent includes carbon nanotubes and / or graphene, and the binder includes polyacrylic acid binders.

[0017] The polyacrylic adhesives of this invention include any one or a combination of at least two of polyacrylic acids, polyacrylic acid derivatives, polyacrylonitrile, polyacrylamide, polyacrylates, or polyacrylic acid copolymers.

[0018] The method for preparing negative electrode slurry provided by this invention, through the mixing sequence and the addition of a new solvent, suppresses the strong interaction between PAA-type binders and carbon nanotubes and graphene conductive agents, thus solving the problems of slurry processing and electrode sheet processing difficulties caused by the difficulty in dispersing negative electrode slurry, excessive viscosity, and severe gelation.

[0019] The preparation method provided by this invention first mixes a first conductive agent with a first solvent to achieve contact between the first solvent and the first conductive agent, forming hydrogen bonds or strong π-π conjugation or dipole-dipole interaction. Then, a binder is added. The first solvent plays a role in inhibiting the interaction between the first conductive agent and the binder. If the first mixed slurry is not prepared first, the slurry viscosity will be abnormally high and unstable, and in severe cases, gelation will occur. If the first solvent is not introduced, it is impossible to hinder the interaction between the first conductive agent and the binder.

[0020] Preferably, in step (1), the first solvent includes any one or at least a combination of two of isopropanol, n-butanol, ethylene carbonate, lauric acid, or sodium carboxymethyl cellulose of low molecular weight.

[0021] The specific range of the low molecular weight sodium carboxymethyl cellulose in this invention is 10,000 to 100,000, and its viscosity is less than 0.3 Pa*s.

[0022] In this invention, the substance of the first solvent is mixed with the first conductive agent to eliminate or reduce active groups such as hydrogen bonds on the surface of the first conductive agent. However, if an alcohol solvent is not used, it is difficult to achieve the surface treatment of the first conductive agent by using water or NMP.

[0023] Preferably, the solid content of the first mixed slurry in step (1) is 0.6% to 1%, for example, 0.6%, 0.7%, 0.8%, 0.9% or 1%.

[0024] In this invention, if the solid content of the first mixed slurry in step (1) is too small, it will result in too much first solvent, which will affect the dispersion of the binder. If the solid content is too large, it will affect the treatment of the first conductive agent.

[0025] Preferably, in step (2), the second solvent includes water.

[0026] Preferably, the solid content of the second mixed slurry in step (2) is 3% to 10%, such as 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10%.

[0027] In this invention, if the solid content of the second mixed slurry in step (2) is too low, it will result in a low solid content of the subsequent slurry and cause the first solvent to be over-diluted in the second mixed slurry, reducing the effect. If the solid content is too high, it will affect the dispersion of the binder in the second slurry.

[0028] Preferably, the negative electrode active material in step (2) is graphite and / or silicon-based material.

[0029] Preferably, in step (2), the second conductive agent comprises any one or a combination of at least two of carbon black, graphite, or carbon nanofibers.

[0030] Preferably, the mass ratio of the first conductive agent in step (1) to the second conductive agent in step (2) is (0.3-1.5):(1-2), for example, 0.3:1, 0.3:1.5, 0.3:2, 1:1.5, 1:2, 1.5:1.8 or 1.5:2, etc.

[0031] In this invention, the mass of the first conductive agent is less than the mass of the second conductive agent. If too much of the first conductive agent is added, it will affect the dispersion and stability of the final slurry and also affect the electrical performance of the battery.

[0032] Preferably, the solid content of the fourth mixed slurry in step (3) is 65-80%, such as 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, or 80%.

[0033] Preferably, the solid content of the negative electrode slurry is 40-50%, such as 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, or 50%.

[0034] As a preferred technical solution, the preparation method includes the following steps:

[0035] (1) The first conductive agent and isopropanol are mixed to obtain a first mixed slurry with a solid content of 0.6-1%;

[0036] (2) Mix the binder, the second solvent and the first mixed slurry from step (1) to obtain a second mixed slurry with a solid content of 3 to 10%;

[0037] The negative electrode active material is mixed with the second conductive agent. In step (1), the mass ratio of the first conductive agent to the second conductive agent in step (2) is (0.3-1.5):(1-2), to obtain the third mixture.

[0038] (3) Take a portion of the second mixed slurry and mix it with the third mixed slurry to obtain a fourth mixed slurry with a solid content of 65% to 80%;

[0039] (4) Take another part of the second mixed slurry and mix it with the fourth mixed slurry to obtain the fifth mixed slurry. Add the second solvent to adjust the solid content again to obtain the negative electrode slurry with a solid content of 40-50%.

[0040] The first conductive agent includes carbon nanotubes and / or graphene, and the binder includes polyacrylic acid binders.

[0041] In a second aspect, the present invention provides a negative electrode slurry, which is prepared by the method for preparing negative electrode slurry as described in the first aspect; the negative electrode slurry includes a negative electrode active material, a first conductive agent, a second conductive agent, a binder, a first solvent, and a second solvent.

[0042] In this invention, the mass ratio of the negative electrode active material, binder and total conductive agent is a conventional technical selection, which conforms to the rule of adding non-solvent substances in conventional negative electrode slurry. This invention is applicable to all of them. For example, the mass ratio of the negative electrode active material, binder and total conductive agent is (94~98):(0.5~3):(1.5~3).

[0043] Thirdly, the present invention provides a negative electrode sheet, which is obtained by coating the negative electrode slurry as described in the second aspect onto the surface of the current collector, drying it, and then rolling it.

[0044] Fourthly, the present invention also provides a lithium-ion battery, the lithium-ion battery comprising the negative electrode sheet as described in the third aspect.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] The method for preparing negative electrode slurry provided by this invention, through the mixing sequence and the addition of new solvents, suppresses the strong interaction between PAA-type binders and carbon nanotubes and graphene conductive agents, thus solving the problems of difficult dispersion, excessive viscosity, and severe gelation of negative electrode slurry, as well as the difficulties in processing electrode sheets. Moreover, it can be achieved without re-customizing and modifying homogenizing equipment, and at the same time, it also improves the battery internal resistance and other battery performance. Detailed Implementation

[0047] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments are merely illustrative of the present invention and should not be construed as limiting the invention.

[0048] Example 1

[0049] This embodiment provides a method for preparing a negative electrode slurry (the mass ratio of negative electrode active material (graphite and silicon oxide materials), polyacrylic acid, Super P and carbon nanotubes in the non-solvent portion of the negative electrode slurry is 94:3:2:1), and the preparation method is as follows:

[0050] (1) Mix carbon nanotubes with isopropanol, stir at low speed first and then at high speed for a total of 60 min to obtain a first mixed slurry with a solid content of 0.8%;

[0051] (2) Add the polyacrylic acid copolymer binder and water to the first mixed slurry, stir at medium speed first and then at high speed for a total of 60 minutes to obtain the second mixed slurry with a solid content of 5%;

[0052] (3) Dry mix artificial graphite, silicon oxide and conductive carbon black (Super P) and stir at low speed for 20 minutes to obtain the third mixed dry material.

[0053] (4) Take a portion of the second mixed slurry and add it to the third mixed dry material. First, stir at low speed for 15 minutes, then stir at high speed for 45 minutes, and simultaneously disperse for a total of 60 minutes to obtain a fourth mixed slurry with a solid content of 73%.

[0054] (5) Take the remaining second mixed slurry and add it to the fourth mixed slurry. First, stir at low speed for 10 minutes, then vacuum and stir at high speed for 120 minutes, while simultaneously dispersing for a total of 130 minutes to obtain the fifth mixed slurry. Add water to adjust the slurry viscosity according to the slurry viscosity, and turn on the vacuum state for high-speed stirring and dispersing for a total of 30 minutes. Finally, after passing through a 150-mesh screen, the final negative electrode slurry required for coating is obtained, with a solid content of 45%.

[0055] Example 2

[0056] This embodiment provides a method for preparing a negative electrode slurry (the mass ratio of negative electrode active material (graphite and silicon oxide materials), polyacrylic acid, Ketjen black and carbon nanotubes in the non-solvent portion of the negative electrode slurry is 95:2.5:1.5:1), and the preparation method is as follows:

[0057] (1) Mix carbon nanotubes with isopropanol, stir at low speed first and then at high speed for a total of 65 minutes to obtain a first mixed slurry with a solid content of 0.6%;

[0058] (2) Add the polyacrylic acid copolymer and water to the first mixed slurry, stir at medium speed and then at high speed for a total of 55 minutes to obtain the second mixed slurry with a solid content of 3%;

[0059] (3) Dry mix natural graphite, silicon oxide and conductive carbon black (Ketjen black) and stir at low speed for 20 minutes to obtain the third mixed dry material.

[0060] (4) Take a portion of the second mixed slurry and add it to the third mixed dry material. First, stir at low speed for 15 minutes, then stir at high speed for 45 minutes, and simultaneously disperse for a total of 60 minutes to obtain a fourth mixed slurry with a solid content of 65%.

[0061] (5) Take the remaining second mixed slurry and add it to the fourth mixed slurry. First, stir at low speed for 20 minutes, then vacuum and stir at high speed for 130 minutes, while simultaneously dispersing for a total of 150 minutes to obtain the fifth mixed slurry. Add water to adjust the slurry viscosity according to the slurry viscosity, and turn on the vacuum state for high-speed stirring and dispersing for a total of 50 minutes. Finally, pass it through a 150-mesh screen to obtain the final negative electrode slurry required for coating, with a solid content of 40%.

[0062] Example 3

[0063] This embodiment provides a method for preparing a negative electrode slurry (negative electrode active material (graphite and silicon oxide material)), the preparation method is as follows:

[0064] (1) Mix graphene with n-butanol, stir at low speed first and then at high speed for a total of 60 minutes to obtain a first mixed slurry with a solid content of 1%.

[0065] (2) Add polyacrylic acid and water to the first mixed slurry, stir at medium speed first and then at high speed for a total of 60 minutes to obtain a second mixed slurry with a solid content of 10%.

[0066] (3) Graphite and silicon oxide materials and conductive carbon black (Super P) are dry mixed and stirred at low speed for 20 minutes to obtain the third mixed dry material;

[0067] (4) Take a portion of the second mixed slurry and add it to the third mixed dry material. First, stir at low speed for 15 minutes, then stir at high speed for 45 minutes, and simultaneously disperse for a total of 60 minutes to obtain a fourth mixed slurry with a solid content of 80%.

[0068] (5) Take the remaining second mixed slurry and add it to the fourth mixed slurry. First, stir at low speed for 10 minutes, then vacuum and stir at high speed for 120 minutes, while simultaneously dispersing for a total of 130 minutes to obtain the fifth mixed slurry. Add water to adjust the slurry viscosity according to the slurry viscosity, and turn on the vacuum state for high-speed stirring and dispersing for a total of 30 minutes. Finally, pass it through a 150-mesh screen to obtain the final negative electrode slurry required for coating, with a solid content of 50%.

[0069] Example 4

[0070] The difference between this embodiment and Embodiment 1 is that the solid content of the first mixed slurry in step (1) of this embodiment is 1.2%.

[0071] The remaining preparation methods and parameters are consistent with those in Example 1.

[0072] Example 5

[0073] The difference between this embodiment and Embodiment 1 is that the solid content of the first mixed slurry in step (1) of this embodiment is 0.1%.

[0074] The remaining preparation methods and parameters are consistent with those in Example 1.

[0075] Example 6

[0076] The difference between this embodiment and embodiment 1 is that the solid content of the second mixed slurry in step (2) of this embodiment is 12%.

[0077] The remaining preparation methods and parameters are consistent with those in Example 1.

[0078] Example 7

[0079] The difference between this embodiment and embodiment 1 is that the solid content of the second mixed slurry in step (2) of this embodiment is 2%.

[0080] The remaining preparation methods and parameters are consistent with those in Example 1.

[0081] Example 8

[0082] The difference between this embodiment and Embodiment 1 is that the solvent in step (1) of this embodiment is NMP.

[0083] The remaining preparation methods and parameters are consistent with those in Example 1.

[0084] Comparative Example 1

[0085] The difference between Comparative Example 1 and Example 1 is that Comparative Example 1 does not perform step (1), but directly mixes carbon nanotubes with binder and water to obtain a second mixed slurry.

[0086] The remaining preparation methods and parameters are consistent with those in Example 1.

[0087] Comparative Example 2

[0088] The difference between Comparative Example 2 and Example 1 is that Comparative Example 2 does not perform steps (1) and (2). Instead, it directly mixes the binder, conductive agent, graphite, silicon oxide and water, then directly adds carbon nanotubes, and then adjusts the viscosity to obtain the final mixed slurry.

[0089] The negative electrode slurries provided in Examples 1-8 and Comparative Examples 1-2 were tested under the following conditions: room temperature, viscosity test using a No. 63 rotor (20 rpm), solid content test temperature of 120℃, slurry fineness and particle size test using the scraper method (100 μm), and electrode peeling force test speed of 100 mm / min. The results are shown in Table 1.

[0090] Table 1

[0091]

[0092] The data results from Examples 1, 4, and 5 show that if the solid content of the first mixed slurry is too high, it will not be conducive to the surface treatment of carbon nanotubes and will affect their dispersion. If the solid content is too low, that is, the first solvent is excessive, it will affect the dispersion of the binder in the second slurry.

[0093] The data results from Examples 1, 6, and 7 show that if the solid content of the second mixed slurry is too high, it will lead to poor dispersion of the binder, while if the solid content is too low, it will be detrimental to the dispersion of agglomerated particles in the slurry, resulting in a higher particle size and decreased stability of the slurry.

[0094] The data from Examples 1 and 8 show that without using alcohol solvents to prepare the first mixed slurry, the surface treatment of carbon nanotubes in the slurry cannot be achieved.

[0095] The data from Example 1 and Comparative Example 1 show that directly mixing the first conductive agent and the binder without preparing the first mixed slurry will result in high slurry viscosity, difficulty in dispersion, and a tendency to gel.

[0096] The data from Example 1 and Comparative Example 2 show that, compared with the conventional negative electrode slurry preparation process, the slurry prepared by the present invention has lower viscosity, better stability, and lower particle size.

[0097] In summary, the negative electrode slurry preparation method provided by this invention, through the mixing sequence and the addition of a new solvent, suppresses the strong interaction between PAA-type binders and carbon nanotubes and graphene conductive agents, thus solving the problems of difficult dispersion, excessive viscosity, and severe gelation of negative electrode slurry, as well as the difficulties in processing electrode sheets. Moreover, it can be achieved without redesigning or modifying the homogenizing equipment, and also improves the battery internal resistance and other battery performance.

[0098] The applicant declares that the detailed process equipment and process flow of this invention are illustrated through the above embodiments, but this invention is not limited to the above detailed process equipment and process flow, that is, it does not mean that this invention must rely on the above detailed process equipment and process flow to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the products of this invention, additions of auxiliary components, and selection of specific methods, all fall within the protection scope and disclosure scope of this invention.

Claims

1. A method for preparing a negative electrode slurry, characterized in that, The preparation method includes the following steps: (1) mixing a first conductive agent and a first solvent to obtain a first mixed slurry; the first solvent includes any one or at least two combinations of isopropanol, n-butanol, ethylene carbonate, and lauric acid; the solid content of the first mixed slurry is 0.6~1%; (2) mixing a binder, a second solvent, and the first mixed slurry of step (1) to obtain a second mixed slurry; the solid content of the second mixed slurry of step (2) is 3~10%; mixing the negative electrode active material with the second conductive agent to obtain a third mixed material; the mass ratio of the first conductive agent of step (1) to the second conductive agent of step (2) is (0.3~1.5):(1~2); (3) taking a portion of the second mixed slurry and mixing it with the third mixed material to obtain a fourth mixed slurry; (4) taking another portion of the second mixed slurry and mixing it with the fourth mixed slurry to obtain a fifth mixed slurry, adding the second solvent and mixing again to obtain the negative electrode slurry; wherein, the first conductive agent includes carbon nanotubes and / or graphene, and the binder includes polyacrylic acid binders.

2. The method for preparing the negative electrode slurry according to claim 1, characterized in that, Step (2) The second solvent includes water.

3. The method for preparing the negative electrode slurry according to claim 1, characterized in that, The negative electrode active material in step (2) is graphite and silicon-based material.

4. The method for preparing the negative electrode slurry according to claim 1, characterized in that, Step (2) The second conductive agent includes any one or a combination of at least two of carbon black, graphite or carbon nanofibers.

5. The method for preparing the negative electrode slurry according to claim 1, characterized in that, The solid content of the fourth mixed slurry in step (3) is 65-80%.

6. The method for preparing the negative electrode slurry according to claim 1, characterized in that, The solid content of the negative electrode slurry is 40-50%.

7. The method for preparing the negative electrode slurry according to claim 1, characterized in that, The preparation method includes the following steps: (1) mixing a first conductive agent and isopropanol to obtain a first mixed slurry with a solid content of 0.6-1%; (2) mixing a binder, a second solvent and the first mixed slurry of step (1) to obtain a second mixed slurry with a solid content of 3-10%; mixing a negative electrode active material with a second conductive agent to obtain a third mixture; the mass ratio of the first conductive agent of step (1) to the second conductive agent of step (2) is (0.3-1.5):(1-2); (3) taking a portion of the second mixed slurry and mixing it with the third mixture to obtain a fourth mixed slurry with a solid content of 65%-80%; (4) taking another portion of the second mixed slurry and mixing it with the fourth mixed slurry to obtain a fifth mixed slurry, adding a second solvent to adjust the solid content again to obtain a negative electrode slurry with a solid content of 40-50%; wherein, the first conductive agent includes carbon nanotubes and / or graphene, and the binder includes polyacrylic acid binders.

8. A negative electrode slurry, characterized in that, The negative electrode slurry is prepared by the method for preparing negative electrode slurry as described in any one of claims 1-7; the negative electrode slurry includes a negative electrode active material, a first conductive agent, a second conductive agent, a binder, a first solvent, and a second solvent.

9. A negative electrode sheet, characterized in that, The negative electrode sheet is obtained by coating the negative electrode slurry as described in claim 8 onto the surface of the current collector, drying, and then rolling.

10. A lithium-ion battery, characterized in that, The lithium-ion battery includes the negative electrode sheet as described in claim 9.

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