Lithium-ion battery negative electrode mixture, negative electrode and lithium-ion battery

Abstract

The present invention belongs to the technical field of lithium-ion batteries, and specifically discloses a negative electrode mixture for lithium-ion batteries, a negative electrode, and a lithium-ion battery. The negative electrode mixture for lithium-ion batteries comprises a negative electrode active material, a conductive agent, a thickener, and a binder, wherein the thickener is a grafted modified konjac glucomannan. In the negative electrode mixture for lithium-ion batteries provided in an embodiment of the present invention, the thickener adopts grafted modified konjac glucomannan. Since the thickener has excellent compliance and can improve the conductivity of lithium ions in lithium-ion batteries, the NaCMC / SBR combined binder can be replaced with less grafted modified konjac glucomannan and a binder. This not only increases the content of the negative electrode active material in the negative electrode, but also, since the grafted modified konjac glucomannan itself has lithium ion transmission capacity, the low-temperature performance and rate performance are obviously better, thereby further improving the electrochemical performance of the lithium-ion battery.

Description

Technical Field

[0001] The present invention belongs to the technical field of lithium ion batteries, and in particular relates to a lithium ion battery negative electrode mixture, a negative electrode and a lithium ion battery. Background Art

[0002] The positive and negative electrodes of lithium-ion batteries are primarily composed of active materials, binders, conductive agents, and current collectors. Common binders are polymer compounds that are primarily used to adhere the electrode active materials to the current collector surface, bonding and retaining the active materials. This enhances electronic contact between the electrode active material and the conductive agent, and between the active material and the current collector, ultimately stabilizing the electrode structure.

[0003] Because the positive and negative electrodes of lithium-ion batteries expand and contract during the charge and discharge process, a binder is required to buffer this expansion and contraction. Although the amount of binder used in the positive and negative electrodes of lithium-ion batteries is not very high, its adhesion and flexibility often directly affect the final performance of the lithium-ion battery. Therefore, selecting the right binder is crucial to maximize the performance of lithium-ion batteries.

[0004] Currently, commercial lithium-ion batteries typically use polyvinylidene fluoride (PVDF) as a binder. This is primarily due to PVDF's strong adhesion to electrode materials and current collectors, as well as its excellent thickening and dispersing properties in slurries. However, using PVDF as a binder requires a certain amount of NMP as a dispersant, but NMP is environmentally friendly and expensive.

[0005] Meanwhile, there are also binder systems on the market that use NaCMC / SBR as a binder. This type of binder system uses water as a dispersant, is more environmentally friendly than PVDF during production, and offers significant price advantages. As a result, negative electrode material binders are gradually shifting towards water-based systems.

[0006] However, in the NaCMC / SBR binder combination, the SBR component primarily acts as a binder in the electrode, necessitating the addition of NaCMC to maintain a stable suspension of the active material in the slurry. This is because NaCMC acts as a surfactant, improving the wettability of the active material with water. It also acts as a dispersant and thickener, preventing aggregation and precipitation of the active material. PVDF, on the other hand, combines both functions of the NaCMC / SBR binder combination. This results in a NaCMC / SBR binder containing 2% to 3% less active material in the negative electrode formulation, or even less, than a PVDF binder. This reduction in negative electrode active material leads to a decrease in lithium-ion conductivity. Consequently, when used in lithium-ion batteries, negative electrode sheets prepared with the NaCMC / SBR binder combination exhibit inferior low-temperature, rate, and cycling performance compared to oil-based systems. Summary of the Invention

[0007] The purpose of the embodiments of the present invention is to solve the problem that the existing aqueous binder reduces the lithium ion conductivity of lithium ion batteries, and to provide a negative electrode mixture for lithium ion batteries.

[0008] Another object of the embodiments of the present invention is to provide a lithium ion battery negative electrode and a lithium ion battery prepared from the lithium ion battery negative electrode mixture.

[0009] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0010] A negative electrode mixture for a lithium ion battery comprises a negative electrode active material, a conductive agent, a thickener and a binder, wherein the thickener is grafted modified konjac glucomannan.

[0011] Correspondingly, a negative electrode for a lithium-ion battery includes a negative electrode active layer, wherein the negative electrode active layer is formed by the above-mentioned negative electrode mixture for the lithium-ion battery.

[0012] And, accordingly, a lithium-ion battery provided by the above-mentioned lithium-ion battery negative electrode.

[0013] The lithium ion battery negative electrode mixture thickener provided by the above embodiment adopts graft modified konjac glucomannan.Because the weight average molecular weight of konjac glucomannan is millions of daltons, the commercial product viscosity of industrial production can reach 20Pa·s, which is dozens or even hundreds of times the viscosity of NaCMC thickener under the same concentration. Using less konjac glucomannan can produce a satisfactory thickening effect. Simultaneously, because the konjac glucomannan molecular chain contains a large amount of hydroxyl groups, after graft modification, not only the compliance performance is more superior, but other properties such as lithium ion conductivity are also correspondingly improved. Therefore, a small amount of graft modified konjac glucomannan is used to replace the NaCMC in the lithium ion battery negative electrode mixture, thereby improving the ratio of active material in the electrode sheet.

[0014] The lithium-ion battery negative electrode provided in the above embodiment is used in a lithium-ion battery. Since the amount of thickener used in the negative electrode mixture is reduced, the proportion of the negative electrode active material in the negative electrode material is increased, thereby improving the energy density of the lithium-ion battery. Moreover, since the thickener uses modified konjac glucomannan, the conductivity of lithium ions is effectively improved, ultimately improving the performance of the lithium-ion battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 250 cycles performance comparison diagram of lithium-ion batteries prepared with the lithium-ion battery negative electrode materials provided in Example 1-Cell1 and Comparative Example 1-Cell5 of the present invention at room temperature. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0017] An embodiment of the present invention provides a negative electrode mixture for a lithium ion battery, comprising a negative electrode active material, a conductive agent, a thickener and a binder, wherein the thickener is grafted modified konjac glucomannan.

[0018] In any embodiment, the negative electrode active material is at least one of natural graphite, artificial graphite, surface-modified natural graphite, hard carbon, soft carbon, mesophase carbon microspheres, polycrystalline silicon microwires, polycrystalline silicon nanoparticles, silicon-based alloy powder, and silicon oxide microparticles.

[0019] Preferably, the conductive agent is at least one of conductive carbon black, conductive graphite, vapor-grown carbon fiber, multi-walled carbon nanotubes, single-walled carbon nanotubes and graphene.

[0020] In any embodiment, thickening agent is graft modified konjac glucomannan.And graft modified konjac glucomannan is carried out graft modification by konjac glucomannan, the molecular weight of konjac glucomannan is millions of daltons, the commodity viscosity of industrial production can reach 20Pas, is a kind of material with the highest viscosity in the practical glue of the plant class found at present, under same concentrations, its viscosity is tens or even hundreds of times of NaCMC glue viscosity, this means that in actual application, the konjac glucomannan glue of very low concentration just can produce satisfied thickening effect.Contain a large amount of hydroxyls in the molecular chain of konjac glucomannan simultaneously, can carry out modification treatments such as grafting easily to it, can give it and have the new function that is applicable to various purposes, thereby expand its range of application.

[0021] Preferably, the grafted modified konjac glucomannan is at least one of polyethylene oxide grafted modified konjac glucomannan, polypropylene oxide grafted modified konjac glucomannan, polyethylene glycol grafted modified konjac glucomannan, polysiloxane grafted modified konjac glucomannan, polyethylene glycol succinate grafted modified konjac glucomannan, polyethyleneimine grafted modified konjac glucomannan and polyacrylonitrile grafted modified konjac glucomannan.

[0022] After konjac glucomannan is modified into the grafted modified konjac glucomannan, the molecular chain becomes more flexible and has good lithium ion conductivity, which increases the proportion of active substances in the electrode sheet and can increase the energy density of the electrode, thereby helping to improve various electrochemical properties of battery products.

[0023] Preferably, the weight average molecular weight of the grafted modified konjac glucomannan is 1×10 6 ~2×10 6 This content can ensure both a significant thickening effect and a higher dissolution rate in water.

[0024] Preferably, the thickener, i.e., grafted modified konjac glucomannan, accounts for 0% to 1.0% of the total mass percentage of the lithium-ion battery negative electrode mixture. This content can reduce the amount of thickener used while ensuring flexibility and lithium ion conductivity, thereby greatly increasing the proportion of active material in the electrode sheet.

[0025] Preferably, the binder is at least one of polyvinylidene fluoride (PVDF), styrene-butadiene rubber (SBR), polyvinyl alcohol, polyacrylate, polymethyl methacrylate, polyacrylamide, polyamic acid, polyimide, polyamide-imide and sodium alginate.

[0026] Accordingly, the present invention further provides a lithium-ion battery negative electrode based on the above-mentioned lithium-ion battery negative electrode mixture. In one embodiment, the lithium-ion negative electrode includes a negative electrode current collector and a negative electrode active layer coated on the surface of the negative electrode current collector. The negative electrode active layer is formed by coating, rolling, or other processes after the above-mentioned lithium-ion battery negative electrode mixture is formed into a slurry. That is, the lithium-ion battery negative electrode mixture is formed into a slurry and then coated on the surface of the negative electrode current collector according to conventional lithium-ion battery negative electrode production processes to form the negative electrode active layer.

[0027] Accordingly, based on the lithium ion battery negative electrode mixture and the lithium ion battery negative electrode provided in the above embodiments, the embodiments of the present invention also provide a corresponding lithium ion battery.

[0028] In one embodiment, the lithium-ion battery includes a positive electrode sheet, a negative electrode sheet, a separator separated between adjacent positive and negative electrode sheets, and an electrolyte, wherein the negative electrode sheet is the lithium-ion battery negative electrode provided in the above embodiment of the present invention, or is formed by forming a slurry from the above lithium-ion negative electrode mixture and then coating it on the surface of the negative electrode current collector.

[0029] Preferably, the positive electrode sheet uses a lithium-containing composite metal oxide as the positive electrode active material, such as lithium ferrous phosphate, lithium cobalt oxide, lithium nickel cobalt manganese oxide, etc., but is not limited to these listed positive electrode active materials.

[0030] The positive electrode active material is formed into a slurry and then coated on a positive electrode current collector to form a positive electrode sheet.

[0031] Specifically, the positive electrode current collector is aluminum or aluminum foil coated with conductive carbon.

[0032] Preferably, the electrolyte consists of an electrolyte solvent and an electrolyte solute.

[0033] The electrolyte solvent is at least one of ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), and methylpropyl carbonate (MPC).

[0034] The solute of the electrolyte is at least one of lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), lithium perchlorate (LiClO4), lithium bis(fluorosulfonyl)imide (LiN(SO2F)2), lithium bis(trifluoromethylsulfonyl)imide (LiN(CF3SO2)2), lithium bis(oxalatoborate) (LiBOB), and lithium difluorooxalatoborate (LiDFOB).

[0035] The lithium ion battery manufactured using the negative electrode material or negative electrode provided by the embodiment of the present invention, adopts graft-modified konjac glucomannan as the thickener of negative electrode material in combination with at least one of polyvinylidene fluoride, styrene-butadiene rubber, polyvinyl alcohol, polyacrylate, polymethyl methacrylate, polyacrylamide, polyamic acid, polyimide, polyamide-imide and sodium alginate to form a combined binder, replacing the NaCMC / SBR combined binder, which can reduce the amount of thickener and binder, thereby increasing the proportion of active material in the negative electrode sheet of the lithium ion battery, and the increase in the proportion of active material can improve the energy density of the electrode. More importantly, the graft-modified konjac glucomannan used not only has a more flexible molecular chain, but also has a good lithium ion conductivity effect, which ultimately helps to improve the various electrochemical properties of the battery product.

[0036] In order to better illustrate the embodiments of the present invention, the lithium-ion negative electrode mixture, negative electrode and lithium-ion battery provided by the embodiments of the present invention are illustrated below through multiple examples.

[0037] Example 1

[0038] Preparation of negative electrode sheet N1. The components were weighed in a weight ratio of natural graphite: polyethylene oxide grafted modified konjac glucomannan: styrene-butadiene rubber: conductive carbon black: deionized water = 98.5:0.1:0.4:1:80. The symmetrically weighed components were then stirred at high speed to obtain a uniformly dispersed negative electrode slurry. This slurry was evenly applied to both sides of a copper foil, dried, and compacted using a roller press to obtain a negative electrode sheet designated N1.

[0039] Preparation of positive electrode sheet P1. Weigh the components according to a weight ratio of lithium cobalt oxide: polyvinylidene fluoride: conductive carbon black: N-methylpyrrolidone = 90:5:5:40. High-speed stirring is then performed to obtain a uniformly dispersed positive electrode slurry. This slurry is evenly coated on both sides of aluminum foil, dried, and compacted using a roller press to obtain the positive electrode sheet, designated P1.

[0040] Preparation of lithium-ion battery Cell 1. Conductive tabs were welded to the positive electrode sheet P1 and the negative electrode sheet N1. A polypropylene / polyethylene composite separator was placed between the positive and negative electrodes. This was then wound to form a bare cell, which was then wrapped in aluminum-plastic film. An electrolyte consisting of a 1M lithium salt and a mixed carbonate solvent was injected. After packaging, the battery was formed and aged to produce a soft-package battery, designated Cell 1.

[0041] Example 2

[0042] Preparation of negative electrode sheet N2. Weigh the components according to a weight ratio of artificial graphite: polyethylene glycol grafted modified konjac glucomannan: polyacrylate: vapor-grown carbon fiber: water = 98:0.2:0.8:1:100. These components are then stirred at high speed to obtain a uniformly dispersed negative slurry. This slurry is evenly applied to both sides of copper foil, dried, and compacted using a roller press to obtain the negative electrode sheet, designated N2.

[0043] Preparation of positive electrode sheet P2. Lithium nickel cobalt manganese oxide, polyvinylidene fluoride, conductive carbon black, and N-methylpyrrolidone were weighed in a weight ratio of 92:4:4:45. The symmetrically weighed components were then stirred at high speed to obtain a uniformly dispersed positive electrode slurry. This slurry was evenly coated on both sides of aluminum foil, dried, and compacted using a roller press to obtain the resulting positive electrode sheet, designated P2.

[0044] Preparation of the lithium-ion battery Cell2. Conductive tabs were welded to the positive electrode sheet P2 and the negative electrode sheet N2. A polypropylene / polyethylene composite separator was placed between the positive and negative electrodes. This was then wound to form a bare cell, which was then wrapped in aluminum-plastic film. An electrolyte consisting of a 1M lithium salt and a mixed carbonate solvent was injected. After packaging, the battery was formed and aged to produce a soft-package battery, designated Cell2.

[0045] Example 3

[0046] Preparation of negative electrode sheet N3: The components were weighed in a weight ratio of silicon-based alloy powder: polysiloxane-grafted modified konjac glucomannan: polyacrylamide: multi-walled carbon nanotubes: water = 97.5:0.5:1.0:1:90. These components were stirred at high speed to obtain a uniformly dispersed negative electrode slurry. This slurry was evenly coated on both sides of copper foil, dried, and compacted using a roller press to obtain a negative electrode sheet designated N3.

[0047] Preparation of positive electrode sheet P3. The components were weighed in a weight ratio of lithium nickel cobalt aluminum oxide (LNiCoA): polyvinylidene fluoride (PVDF): conductive carbon black: N-methylpyrrolidone (NMP) = 93:3.5:3.5:50. These components were then stirred at high speed to obtain a uniformly dispersed positive electrode slurry. This slurry was evenly coated on both sides of aluminum foil, dried, and compacted using a roller press to obtain a positive electrode sheet designated P3.

[0048] Preparation of the lithium-ion battery Cell3. Conductive tabs were welded to the positive electrode sheet P3 and the negative electrode sheet N3. A polypropylene / polyethylene composite separator was placed between the positive and negative electrodes. This was then wound to form a bare cell, which was then wrapped in aluminum-plastic film. An electrolyte consisting of a 1M lithium salt and a mixed carbonate solvent was injected. After packaging, the battery was formed and aged to produce a soft-package battery, designated Cell3.

[0049] Example 4

[0050] Preparation of negative electrode sheet N4. Components were weighed in a weight ratio of 97:1:11:1:80 for silicon dioxide microparticles: polyethyleneimine-grafted modified konjac glucomannan: polyimide: conductive carbon black: water. These components were then stirred at high speed to obtain a uniformly dispersed negative electrode slurry. This slurry was evenly coated on both sides of copper foil, dried, and compacted using a roller press to obtain a negative electrode sheet designated N4.

[0051] Preparation of positive electrode sheet P4. The components were weighed in a weight ratio of lithium iron phosphate: polyvinylidene fluoride: conductive carbon black: N-methylpyrrolidone = 97:1.5:1.5:70, and then stirred at high speed to obtain a uniformly dispersed positive electrode slurry. This slurry was evenly coated on both sides of aluminum foil, dried, and compacted using a roller press to obtain a positive electrode sheet designated P4.

[0052] Preparation of the lithium-ion battery Cell 4: Conductive tabs were welded to the positive electrode sheet P4 and the negative electrode sheet N4. A polypropylene / polyethylene composite separator was placed between the positive and negative electrodes. This was then wound to form a bare cell, which was then wrapped in aluminum-plastic film. An electrolyte consisting of a 1M lithium salt and a mixed carbonate solvent was then injected. After packaging, the battery was formed and aged to produce a soft-package battery, designated Cell 4.

[0053] Comparative Example 1

[0054] The difference from Example 1 is that the negative electrode sheet is prepared according to the weight ratio of natural graphite: styrene-butadiene rubber: sodium carboxymethyl cellulose: conductive carbon black: water = 94:2:2.6:1.4:100. The negative electrode sheet obtained in this way is recorded as N5.

[0055] With P1 as the positive electrode and N5 as the negative electrode, and other conditions being the same as in Example 1, a lithium ion battery was obtained, which was designated as Cell5.

[0056] The following experimental data further illustrates various properties of the lithium-ion battery negative electrode sheet and the lithium-ion battery using the negative electrode sheet provided by the embodiments of the present invention.

[0057] (1) Comparison of low-temperature performance between Cell 1 and Cell 5

[0058] The battery was charged at 25°C at a current of 0.5C until the voltage reached 4.2V. The charged battery was then discharged at a current of 0.5C until the voltage reached 2.5V. This discharge capacity was recorded as the discharge capacity at 25°C. Similarly, the battery was charged at 25°C at a current of 0.5C until the voltage reached 4.2V. The charged battery was then discharged at 0°C at 0°C, -10°C, and -20°C, respectively, until the voltage reached 2.5V. This discharge capacity was recorded as the discharge capacity at 0°C, -10°C, and -20°C, respectively. The percentage of the discharge capacity at 0°C, -10°C, and -20°C to the initial discharge capacity of the battery at 25°C was used as the battery's 0°C, -10°C, and -20°C discharge capacity ratio. The test results are detailed in Table 1.

[0059] Table 1 Low temperature performance of lithium ion batteries of Example 1 and Comparative Example 1

[0060]

[0061] As can be seen from Table 1, the low-temperature capacity retention rate of the lithium-ion battery of Example 1 at -20°C / 25°C is 71.38%, while the low-temperature capacity retention rate of the comparative example 1 at -20°C / 25°C is only 53.84%. Given that the performance of the lithium-ion battery provided by the embodiment of the present invention has good uniformity and stability, it is obvious that the lithium-ion battery provided by the embodiment of the present invention has better low-temperature performance.

[0062] (2) Comparison of rate performance between Cell1 and Cell5

[0063] The battery was charged at a current of 0.5C until the voltage reached 4.2V. The charged battery was then discharged at a current of 0.5C until the voltage reached 2.5V. This discharge capacity was recorded as the 0.5C discharge capacity. Similarly, the battery was charged at a current of 0.5C until the voltage reached 4.2V. The charged battery was then discharged at currents of 1C, 2C, and 3C until the voltage reached 2.5V. These discharge capacities were recorded as the 1C, 2C, and 3C discharge capacities, respectively. The percentage of the discharge capacity at 1C, 2C, and 3C to the battery's initial 0.5C discharge capacity was used as the battery's 1C, 2C, and 3C discharge capacity ratios. The test results are detailed in Table 2.

[0064] Table 2 Rate performance of lithium ion batteries of Example 1 and Comparative Example 1

[0065]

[0066] As shown in Table 2, the 3C / 0.5C capacity retention rate of the lithium-ion battery of Example 1 is 84.27%, while the 3C / 0.5C capacity retention rate of the lithium-ion battery of Comparative Example 1 is only 71.56%. Given the good uniformity and stability of the performance of the lithium-ion batteries provided by the embodiments of the present invention, it is clear that the lithium-ion battery of Example 1 has better rate performance, that is, the lithium-ion battery provided by the embodiments of the present invention has better rate performance.

[0067] (III) Comparison of room temperature cycling performance between Cell 1 and Cell 5

[0068] At 25°C, charge the battery at a current of 1C until the voltage reaches 4.2V, and discharge the charged battery at a current of 1C until the voltage reaches 2.5V. Repeat the charge and discharge cycle 250 times. Record the discharge capacity of the battery during the cycle, and use the percentage of the 250th discharge capacity to the first discharge capacity as the capacity retention rate. For detailed test results, see the attached manual. Figure 1 .

[0069] Attached to the instruction manual Figure 1 It can be seen that the lithium-ion battery of Example 1 has a capacity retention rate of 92.17% in the room temperature cycle test, while the corresponding capacity retention rate of the lithium-ion battery of Comparative Example 1 is only 80.17%. Clearly, the lithium-ion battery of Example 1 has better cycle performance. Furthermore, given the good uniformity and stability of the performance of the lithium-ion battery provided by the embodiment of the present invention, the lithium-ion battery provided by the embodiment of the present invention has even better cycle performance.

[0070] In summary, the lithium ion battery negative electrode mixture provided by the embodiment of the present invention and the negative electrode prepared by the negative electrode mixture, and the lithium ion battery further manufactured, since only the active material in the negative electrode sheet has lithium ion conductivity, and the grafted modified konjac glucomannan thickener not only has a flexible molecular chain but also has good lithium ion conductivity, combined with conventional binders, so that the total amount of thickener and binder is less than that of NaCMC / SBR combined binder, the active material content in the negative electrode sheet is higher, so the low temperature and rate performance are better; especially in the cycle process, the possibility of side reactions is also greatly reduced, so the battery capacity retention ability is also significantly improved. The remaining embodiments also have the same results, but because the material performance of the present invention is very stable, in order to save space, the other embodiments will not be tested and analyzed one by one here.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A negative electrode mixture for a lithium-ion battery, comprising a negative electrode active material, a conductive agent, a thickener, and a binder, characterized in that: The thickener is grafted modified konjac glucomannan; the grafted modified konjac glucomannan is polyethylene oxide grafted modified konjac glucomannan; the weight average molecular weight is 1×10 6 ~2×10 6 .

2. The negative electrode mixture for lithium-ion batteries according to claim 1, wherein: The grafted modified konjac glucomannan accounts for 0.1% to 1.0% of the total mass percentage of the negative electrode mixture of the lithium ion battery.

3. The negative electrode mixture for lithium-ion batteries according to any one of claims 1 to 2, wherein: The binder is at least one of polyvinylidene fluoride, styrene-butadiene rubber, polyvinyl alcohol, polyacrylate, polymethyl methacrylate, polyacrylamide, polyamic acid, polyimide, polyamide-imide and sodium alginate.

4. The negative electrode mixture for lithium-ion batteries according to any one of claims 1 to 2, wherein: The negative electrode active material is at least one of natural graphite, artificial graphite, surface-modified natural graphite, hard carbon, soft carbon, and mesophase carbon microbeads.

5. The negative electrode mixture for lithium-ion batteries according to any one of claims 1 to 2, wherein: The conductive agent is at least one of conductive carbon black, conductive graphite, vapor-grown carbon fiber, multi-walled carbon nanotubes, single-walled carbon nanotubes and graphene.

6. The negative electrode mixture for lithium-ion batteries according to claim 1, wherein: The lithium-ion battery negative electrode mixture comprises natural graphite, polyethylene oxide grafted modified konjac glucomannan, styrene-butadiene rubber, conductive carbon black and deionized water in a mass ratio of 98.5:0.1:0.4:1:

80.

7. A lithium-ion battery negative electrode, comprising a negative electrode active layer, characterized in that: The negative electrode active layer is formed by the lithium ion battery negative electrode mixture according to any one of claims 1 to 6.

8. A lithium-ion battery, characterized in that: The negative electrode of the lithium-ion battery is the negative electrode of the lithium-ion battery according to claim 7.

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