Lithium ion battery and electronic device comprising same

Abstract

The invention relates to the technical field of electrochemistry, in particular to a lithium ion battery and electronic equipment comprising the same. On one hand, a silicon negative electrode system is used for punching to improve a lithium ion transmission path, on the other hand, the additive shown in the formula I is used in the electrolyte, and an SEI film generated by the additive shown in the formula I is thinner and smaller in impedance; by combined use of the two, side reaction caused by increase of specific surface area due to punching can be effectively inhibited, so that the quick charging performance is improved on the basis of considering other performances; # imgabs0 #

Description

Technical Field

[0001] The present invention belongs to the field of electrochemical technology, and in particular relates to a lithium ion battery and an electronic device comprising the same. Background Art

[0002] Lithium-ion batteries are widely used in digital products, electronic medical, and even in special fields due to their high energy density, stable cycle performance, high operating voltage, low self-discharge, and wide operating temperature range. However, existing lithium-ion batteries can no longer fully meet people's growing actual needs. Especially for consumer products such as mobile phones, the growing demand for charging has become one of the problems that must be overcome.

[0003] Silicon anode is a relatively new type of lithium battery anode material on the market. The theoretical capacity of silicon-carbon anode material generated by alloying silicon and graphite is more than ten times that of pure graphite. Its safety and abundant resource reserves also make it the most promising lithium battery anode material. However, improving the charging capacity of the battery cell and defects such as silicon volume expansion, gas production and capacity failure are currently the most difficult problems. Excessive use of functional additives will increase the viscosity of the electrolyte, thereby affecting the ion transfer rate and greatly affecting the charging performance of the battery cell, so it becomes very difficult to improve the fast charging performance. Summary of the invention

[0004] The present invention aims to solve the technical problems existing in the above-mentioned prior art. To this end, the present invention proposes a lithium-ion battery and an electronic device including the same. The present invention utilizes the pores on the pole piece to shorten the lithium ion transmission rate, thereby improving the fast charging performance. On this basis, it further combines with a new film-forming additive in the lithium-ion battery electrolyte to eliminate the side reactions caused by increasing the specific surface area by drilling, which is beneficial to improving the fast charging performance while ensuring the cycle life of the battery cell.

[0005] In a first aspect of the present invention, a lithium ion battery is provided, comprising an electrolyte, a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive electrode sheet and the negative electrode sheet;

[0006] The electrolyte comprises an additive shown in Formula I, an organic solvent and a lithium salt,

[0007]

[0008] I,

[0009] Wherein, R1, R2, R3, and R4 are each independently selected from the group consisting of non-existent or H, F, * =C, substituted or unsubstituted C1~C 12 Alkyl, substituted or unsubstituted C1~C 12 Alkoxy, substituted or unsubstituted C2~C 12Alkenyl, substituted or unsubstituted C2~C 12 Alkenyloxy; or, any two of R1, R2, R3, and R4 are connected to form a ring;

[0010] The substitution refers to one or more substitutions selected from the following substituent groups: F, aryl;

[0011] * indicates the connection end;

[0012] Based on the total mass of the electrolyte being 100%, the content of the additive represented by formula I is a%, and 0.35≤a≤5;

[0013] The negative electrode plate is a silicon-doped negative electrode plate, the punching ratio of the silicon-doped negative electrode plate is b%, 1≤b≤20, and the amount of silicon doped in the silicon-doped negative electrode plate is c%, 3≤c≤20;

[0014] Among them, 0.3≤b-2a≤10 and 1≤cb / 2≤10.

[0015] The present invention improves the fast charging performance of the battery cell by using a new additive in combination with the pores on the negative electrode plate. The pores can shorten the lithium ion transmission path, but because the specific surface area at the pores increases, more film-forming additives are required. The SEI film generated by the additive used in the present invention is thinner and denser than the conventional SEI, which can reduce the volume expansion of the battery cell. In addition, the present invention finds that the improvement in the fast charging performance of the battery cell is related to the amount of the new additive used, the punching ratio of the negative electrode plate, and the amount of silicon doped in the silicon-doped negative electrode plate.

[0016] In some embodiments of the present invention, C1 to C 12 The alkyl group may be a chain alkyl group or a cyclic alkyl group, and the chain alkyl group may be a straight chain alkyl group or a branched chain alkyl group. 12 The preferred lower limit of the number of carbon atoms in the alkyl group is 1, 2, 3, 4, or 5, and the preferred upper limit is 3, 4, 5, 6, 8, 10, or 12. 10 Alkyl; more preferably, it can be C1~C6 chain alkyl, C3~C8 cyclic alkyl; more preferably, it can be C1~C4 chain alkyl, C5~C7 cyclic alkyl. 12 Examples of alkyl groups include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, hexyl, 2-methyl-pentyl, 3-methyl-pentyl, 1,1,2-trimethyl-propyl, 3,3-dimethyl-butyl, heptyl, 2-heptyl, 3-heptyl, 2-methylhexyl, 3-methylhexyl, isoheptyl, octyl, nonyl, and decyl.

[0017] In some embodiments of the present invention, when the above-mentioned C1 to C 12When the alkyl group contains oxygen atoms, it can be C1~C 12 Preferably, it can be C1~C 10 Alkoxy; more preferably, it can be C1~C6 alkoxy; more preferably, it can be C1~C4 alkoxy. 12 Specific examples of the alkoxy group include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, tert-butoxy, n-pentyloxy, isopentyloxy, cyclopentyloxy and cyclohexyloxy.

[0018] In some embodiments of the present invention, C3~C 12 The alkenyl group may be a cyclic alkenyl group, C2-C 12 It can be a chain alkenyl group, which can be a straight chain alkenyl group or a branched chain alkenyl group. 12 The number of double bonds in the alkenyl group is preferably 1. 12 The preferred lower limit of the number of carbon atoms in the alkenyl group is 2, 3, 4, or 5, and the preferred upper limit is 3, 4, 5, 6, 8, 10, or 12. 10 Preferably, it is C2 to C6 alkenyl; More preferably, it is C2 to C5 alkenyl; More preferably, it is C2 to C4 alkenyl. 12 Specific examples of the alkenyl group include vinyl, allyl, isopropenyl, pentenyl, cyclohexenyl, cycloheptenyl and cyclooctenyl.

[0019] In some embodiments of the present invention, C2 to C 12 Alkenyloxy can be regarded as a C2~C 12 The alkenyl group may be any of linear, branched and cyclic, and examples thereof include alkenyloxy groups having 2 to 8 carbon atoms, preferably 2 to 4 carbon atoms, and specific examples thereof include vinyloxy, allyloxy, 1-propenyloxy, isopropenyloxy, 1-butenyloxy, 2-butenyloxy, 2-methylallyloxy, 1-pentenyloxy, 2-pentenyloxy, 2-methyl-2-butenyloxy, 1-hexenyloxy, 2-hexenyloxy, 3-hexenyloxy, 2-methyl-2-pentenyloxy, 1-heptenyloxy, 2-heptenyloxy, 3-heptenyloxy, 1-octenyloxy, 2-octenyloxy, 3-octenyloxy, 4-octenyloxy, 1-cyclobutenyloxy, 1-cyclopentenyloxy and 1-cyclohexenyloxy.

[0020] In some embodiments of the present invention, the aryl group may be C6 to C 12 The aryl group may be, for example, a phenyl group, a phenylalkyl group, a biphenyl group, or a condensed aromatic hydrocarbon group (eg, a naphthyl group). 12Specific examples of the aryl group include phenyl, benzyl, biphenyl, p-tolyl, o-tolyl, m-tolyl, and naphthyl.

[0021] In some embodiments of the present invention, any two of R1, R2, R3, and R4 connected to form a ring means that: R1 and R2, or, R3 and R4, are bonded to form a ring (for example, a 5-membered to 8-membered saturated carbocyclic ring, a 5-membered to 7-membered saturated carbocyclic ring, a 5-membered to 6-membered saturated carbocyclic ring); or, any one of R1 and R2 is bonded to any one of R3 and R4 to form a ring (for example, a 5-membered to 8-membered saturated carbocyclic ring, a 5-membered to 7-membered saturated carbocyclic ring, a 5-membered to 6-membered saturated carbocyclic ring).

[0022] In some embodiments of the present invention, R1, R2, R3, and R4 are each independently selected from the group consisting of: * =C, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C1-C6 alkoxy, substituted or unsubstituted C2-C6 alkenyl, substituted or unsubstituted C2-C6 alkenyloxy; or, any two of R1, R2, R3, and R4 are connected to form a ring;

[0023] The substitution refers to one or more substitutions selected from the following substituent groups: F, aryl;

[0024] *Indicates the connection end.

[0025] In some embodiments of the present invention, R1, R2, R3, and R4 are each independently selected from the group consisting of: * =C, substituted or unsubstituted C1-C6 alkyl, substituted or unsubstituted C2-C6 alkenyl; or,, any two of R1, R2, R3, R4 are connected to form a ring;

[0026] The substitution refers to substitution by one or more F;

[0027] *Indicates the connection end.

[0028] In some embodiments of the present invention, R1, R2, R3, and R4 are each independently selected from the group consisting of: * =C, substituted or unsubstituted C1-C4 alkyl, substituted or unsubstituted C2-C4 alkenyl; or,, any two of R1, R2, R3, R4 are connected to form a 5- to 8-membered saturated carbocyclic ring;

[0029] The substitution refers to substitution by one or two F;

[0030] *Indicates the connection end.

[0031] In some embodiments of the present invention, the additive represented by formula I is selected from the following compounds:

[0032]

[0033] In some embodiments of the present invention, 0.35≤a≤5, for example, 0.35≤a≤4, 0.35≤a≤3, 0.35≤a≤2, 0.35≤a≤1, 0.5≤a≤3, 0.5≤a≤2, 1≤a≤3, 1≤a≤2.

[0034] In some embodiments of the present invention, 1≤b≤20, for example, 5≤b≤20, 5≤b≤15, 5≤b≤10, 10≤b≤20, 10≤b≤15.

[0035] In some embodiments of the present invention, 3≤c≤20, for example, 5≤c≤20, 5≤c≤15, 5≤c≤10, 10≤c≤20, 10≤c≤15.

[0036] In some embodiments of the present invention, the organic solvent is selected from at least one of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate, propyl carbonate, methyl acetate, ethyl acetate, ethyl propionate, propyl propionate, 1,3-dioxolane, tetrahydrofuran, γ-butyrolactone, 1,2-dimethoxyethane, and 2-methyltetrahydrofuran.

[0037] In some embodiments of the present invention, the organic solvent includes ethylene carbonate, ethyl methyl carbonate and diethyl carbonate.

[0038] In some embodiments of the present invention, the mass ratio of ethylene carbonate, ethyl methyl carbonate and diethyl carbonate in the organic solvent is 1:(0.5-2):(2-6), preferably 1:(0.5-2):(2-4).

[0039] In some embodiments of the present invention, the lithium salt is selected from at least one of lithium hexafluorophosphate, lithium bis(oxalatoborate), lithium perchlorate, lithium tetrafluoroborate, lithium difluorophosphate, lithium trifluoromethylsulfonate, and tris(trifluoromethylsulfonyl)methyllithium.

[0040] In some embodiments of the present invention, the concentration of the lithium salt in the electrolyte is 0.5-1.5 mol / L, for example, 0.5-1.2 mol / L, 0.5-1.0 mol / L, 0.6-1.5 mol / L, 0.6-1.2 mol / L, 0.6-1.0 mol / L, 0.8-1.5 mol / L, 0.8-1.2 mol / L, 0.8-1.0 mol / L, 0.5 mol / L, 0.6 mol / L, 0.8 mol / L, 1.0 mol / L, 1.2 mol / L, 1.4 mol / L, 1.5 mol / L.

[0041] In some embodiments of the present invention, the electrolyte further includes other additives.

[0042] In some embodiments of the present invention, the other additives are selected from at least one of bis(oxalato)borate, lithium difluorosulfonimide, lithium difluorooxalatoborate, lithium tetrafluoroborate, lithium difluorophosphate, lithium difluorobis(oxalato)phosphate, fluoroethylene carbonate (FEC), vinylene carbonate (VC), 1,3-propane sultone (PS), diethylene sulfate (DTD), methylene dimethyl sulfonate (MMDS), propene sultone (PST), citraconic anhydride (CA), ethylene glycol bis(propionitrile) ether (EGBE), and hexanetrinitrile (HTCN).

[0043] In some embodiments of the present invention, the other additives include fluoroethylene carbonate and vinyl sulfate.

[0044] In some embodiments of the present invention, the mass ratio of fluoroethylene carbonate to vinyl sulfate is (4-8):1.

[0045] In some embodiments of the present invention, based on the total mass of the electrolyte being 100%, the content of the other additives is 4% to 10%, for example, 5% to 9%, 6% to 8%.

[0046] In some embodiments of the present invention, the active material of the positive electrode plate includes LiNi x Co y Mn z L (1-x-y-z) O2、LiCo x' L (1-x') O2、LiNi x” L y' Mn (2-x”-y') O4、Li z' At least one of MPO4 and LiMn2O4; wherein L is independently selected from Co, Al, Sr, Mg, Ti, Ca, Zr, Zn, Si, Fe; 0≤x≤1, 0≤y≤1, 0≤z≤1, 0<x+y+z≤1, 0<x'≤1, 0.3<x”≤0.6, 0.01<y'≤0.2, 0.5≤z'≤1, and M is selected from Fe, Mn, and Co.

[0047] In some embodiments of the present invention, the negative electrode sheet is provided with a hole structure, which can be obtained by laser drilling. The drilling ratio of the negative electrode sheet refers to the percentage of the drilling area to the total area of ​​the negative electrode active material.

[0048] In some embodiments of the present invention, the silicon doping amount is the percentage of the mass of the silicon-carbon material to the total mass of the active material in the negative electrode plate.

[0049] In some embodiments of the present invention, the negative electrode plate is a silicon-doped graphite negative electrode plate.

[0050] Another aspect of the present invention provides an electronic device comprising the above-mentioned lithium-ion battery.

[0051] According to some embodiments of the present invention, at least the following beneficial effects are achieved:

[0052] The pores on the negative electrode sheet can shorten the lithium ion transmission path, but because the specific surface area of ​​the hole increases, as the amount of silicon doping increases, the probability of silicon in the laser channel being broken is higher, so it requires more film-forming additives. The film-forming additive used in the present invention has a lower film-forming potential, which can be better than other components to generate a LiF-rich SEI film, which is thinner and denser than conventional SEI, and has a higher elastic modulus, which can effectively reduce the thickness of the side reaction layer outside the active material, thereby reducing the volume expansion of the battery cell. Therefore, the use of the additive shown in Formula I in combination with the holes on the negative electrode sheet can improve the fast charging performance of the battery while taking into account other performances. DETAILED DESCRIPTION

[0053] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0054] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or conditions recommended by the manufacturer. If the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0055] The compounds A to C used in the following examples and comparative examples are:

[0056] Examples 1 to 6

[0057] Embodiments 1 to 6 provide a lithium-ion battery, including an electrolyte, a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive electrode sheet and the negative electrode sheet. The preparation process of the lithium-ion battery is as follows:

[0058] Preparation of electrolyte: In a glove box filled with argon, ethylene carbonate (EC), ethyl methyl carbonate (PC) and diethyl carbonate (DEC) were mixed in a mass ratio of 1:1:3, and then 14.5 wt% of lithium hexafluorophosphate (LiPF6) based on the total weight of the electrolyte was slowly added to the mixed solution, and finally the compound of formula I corresponding to Examples 1 to 6 in Table 1, 6 wt% of fluoroethylene carbonate (FEC) and 1 wt% of vinyl sulfate (DTD) based on the total weight of the electrolyte were added, and the lithium ion battery electrolyte was obtained after stirring.

[0059] Graphite & silicon are selected as the active materials of the negative electrode plate, and holes are punched on the negative electrode surface using a laser punching process to obtain the negative electrode plate. Among them, the laser punching ratio = punching area / total area of ​​anode active material*100%, and the silicon doping amount of the active material = silicon-carbon material mass / total active material mass*100%.

[0060] Preparation of soft-pack batteries: stack the positive electrode sheet (active material is LiCoO2), separator, and negative electrode sheet (active material is graphite & silicon) in order, so that the separator is in the middle of the positive and negative electrode sheets, and wind them to obtain a bare battery cell; place the bare battery cell in an aluminum-plastic film outer package, inject the above-prepared electrolyte into the dried battery, package, let stand, form, shape and divide the capacity to complete the preparation of lithium-ion soft-pack batteries.

[0061] Comparative Examples 1 to 8

[0062] Comparative Examples 1 to 8 provide a lithium ion battery, which is carried out in accordance with Examples 1 to 6, except that the compound of Formula I, the drilling ratio, and the amount of silicon doped are set as shown in Table 1.

[0063] Table 1

[0064]

[0065]

[0066] Test Case

[0067] Relevant performance tests were performed on the batteries prepared in Examples 1-6 and Comparative Examples 1-8.

[0068] (1) Normal temperature cycle performance test: At 25°C, the divided battery is charged to 4.45V at 0.7C constant current and constant voltage, with a cut-off current of 0.05C, and then discharged to 3.0V at 0.5C constant current. After 500 cycles of charge and discharge, the capacity retention rate at the 500th week is calculated. The calculation formula is as follows:

[0069] The 500th cycle capacity retention rate (%) = (500th cycle discharge capacity / first cycle discharge capacity) × 100%.

[0070] (2) 60℃ 14d high temperature storage test: The battery was placed at room temperature and charged and discharged once at 0.5C (4.45V-3.0V), and the discharge capacity C0 of the battery before storage was recorded. The battery was then charged to 4.45V at constant current and constant voltage. The thickness d1 of the battery before high temperature storage was tested using a PPG battery thickness gauge (500g). The battery was placed in a 60℃ constant temperature box and stored for 14 days. After the storage was completed, the battery was taken out and the thermal thickness d2 of the battery after storage was tested. The thickness expansion rate of the battery after 60℃ storage for 14 days was calculated. After the battery was cooled at room temperature for 24h, the battery was again discharged to 3.0V at 0.5C at constant current and then charged to 4.45V at 0.5C at constant current and constant voltage. The discharge capacity C1 and charge capacity C2 of the battery after storage were recorded. The capacity remaining rate and recovery rate of the battery after 60℃ storage for 14 days were calculated using the following formula:

[0071] Thickness expansion ratio after storage at 60°C for 14 days = (d2-d1) / d1*100%;

[0072] After 14 days of storage at 60°C, the remaining capacity = C1 / C0*100%;

[0073] After storage at 60°C for 14 days, the capacity recovery rate = C2 / C0*100%.

[0074] (3) Thermal shock performance: At 25°C, discharge to 3.0V at a given current of 0.2C; leave for 5 minutes; charge to 4.45V at a charging current of 0.2C. When the cell voltage reaches 4.45V, change to 4.45V constant voltage charging until the charging current is less than or equal to the given cut-off current of 0.05C; after leaving for 1 hour, put the cell into an oven, and increase the oven temperature to 135±2°C at a rate of 5±2°C / min, and keep it for 30 minutes before stopping. The judgment standard is that the cell does not catch fire or explode.

[0075] (4) Low temperature cycle performance test: At 0°C, the divided battery is charged to 4.45V at 0.7C constant current and constant voltage, with a cut-off current of 0.05C, and then discharged to 3.0V at 0.5C constant current. After 300 cycles of charge and discharge, the capacity retention rate at the 300th week is calculated. The calculation formula is as follows:

[0076] 300th cycle capacity retention rate (%) = (300th cycle discharge capacity / first cycle discharge capacity) × 100%.

[0077] The results of the above performance tests are shown in Table 2.

[0078] Table 2 Lithium-ion battery and electrolyte performance test results

[0079]

[0080]

[0081] From the comparison of the test results of Comparative Examples 1-3 and Examples 1-6 in Table 2, it can be seen that in the silicon system, the combination of the compound of Formula I and drilling can improve the high-temperature cycling and high-temperature storage performance.

[0082] From the comparison of the test results of Comparative Examples 4-7 and Examples 1 to 6 in Table 2, it can be seen that punching can shorten the lithium ion transmission path and increase the contact area between the electrolyte and the active material. Therefore, a sufficient amount of film-forming additives must be added to ensure a long cycle life of the battery cell, while the silicon system requires an appropriate amount of film-forming additives to ensure the stability of the SEI film during continuous cycling.

[0083] From the comparison of the test results of Comparative Example 8 and Examples 1 to 6 in Table 2, it can be seen that the same amount of 1,4-butanesultone replacing the compound of formula I of the present invention cannot achieve the performance that can be achieved by the compound of formula I. Therefore, the compound of formula I of the present invention can more effectively improve the high and low temperature performance and fast charging performance of the battery than other substances.

[0084] In summary, the lithium-ion battery of the present invention not only exhibits excellent high and low temperature performance and fast charging performance, but can also effectively improve cycle and storage performance.

[0085] The above content describes the embodiments of the present invention in detail, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A lithium ion battery, characterized in that: It includes an electrolyte, a positive electrode sheet, a negative electrode sheet, and a separator arranged between the positive electrode sheet and the negative electrode sheet; The electrolyte comprises an additive shown in Formula I, an organic solvent and a lithium salt, Wherein, R1, R2, R3, and R4 are each independently selected from the group consisting of non-existent or H, F, * =C, substituted or unsubstituted C1~C 12 Alkyl, substituted or unsubstituted C1~C 12 Alkoxy, substituted or unsubstituted C2~C 12 Alkenyl, substituted or unsubstituted C2~C 12 Alkenyloxy; or, any two of R1, R2, R3, and R4 are connected to form a ring; The substitution refers to one or more substitutions selected from the following substituent groups: F, aryl; * indicates the connection end; Based on the total mass of the electrolyte being 100%, the content of the additive represented by formula I is a%, and 0.35≤a≤5; The negative electrode plate is a silicon-doped negative electrode plate, the punching ratio of the silicon-doped negative electrode plate is b%, 1≤b≤20, and the amount of silicon doped in the silicon-doped negative electrode plate is c%, 3≤c≤20; Among them, 0.3≤b-2a≤10 and 1≤cb / 2≤10.

2. The lithium-ion battery according to claim 1, characterized in that R1, R2, R3, R4 are each independently selected from the group consisting of not present or H, F, * =C, substituted or unsubstituted C1~C6 alkyl, substituted or unsubstituted C2~C6 alkenyl; or, any two of R1, R2, R3, and R4 are connected to form a ring.

3. The lithium-ion battery according to claim 2, characterized in that: The additive represented by formula I is selected from the following compounds:

4. The lithium ion battery according to any one of claims 1 to 3, characterized in that The organic solvent is selected from at least one of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, ethylene carbonate, propyl ethyl carbonate, methyl acetate, ethyl acetate, ethyl propionate, propyl propionate, 1,3-dioxolane, tetrahydrofuran, γ-butyrolactone, 1,2-dimethoxyethane, and 2-methyltetrahydrofuran.

5. The lithium ion battery according to any one of claims 1 to 3, characterized in that The lithium salt is selected from at least one of lithium hexafluorophosphate, lithium bis(oxalatoborate), lithium perchlorate, lithium tetrafluoroborate, lithium difluorophosphate, lithium trifluoromethylsulfonate, and tris(trifluoromethylsulfonyl)methyllithium.

6. The lithium ion battery according to any one of claims 1 to 3, characterized in that The concentration of the lithium salt in the electrolyte is 0.5 to 1.5 mol / L.

7. The lithium ion battery according to any one of claims 1 to 3, characterized in that The electrolyte also includes other additives, and the other additives are selected from at least one of bis(oxalatoborate), lithium difluorosulfonimide, lithium difluorooxalatoborate, lithium tetrafluoroborate, lithium difluorophosphate, lithium difluorobis(oxalatophosphate), fluoroethylene carbonate, vinyl carbonate, 1,3-propane sultone, vinyl sulfate, methylene disulfonate, propene sultone, citraconic anhydride, ethylene glycol bis(propionitrile) ether, and hexanetrinitrile.

8. The lithium ion battery according to any one of claims 1 to 3, characterized in that The active material of the positive electrode plate includes LiNi x Co y Mn z L (1-x-y-z) O2、LiCo x' L (1-x') O2、LiNi x” L y' Mn (2-x”-y') O4、Li z' At least one of MPO4 and LiMn2O4; wherein L is independently selected from Co, Al, Sr, Mg, Ti, Ca, Zr, Zn, Si, Fe; 0≤x≤1, 0≤y≤1, 0≤z≤1, 0<x+y+z≤1, 0<x'≤1, 0.3<x”≤0.6, 0.01<y'≤0.2, 0.5≤z'≤1, and M is selected from Fe, Mn, and Co.

9. The lithium ion battery according to any one of claims 1 to 3, characterized in that The negative electrode plate is a silicon-doped graphite negative electrode plate.

10. An electronic device, characterized in that: A lithium ion battery comprising the lithium ion battery according to any one of claims 1 to 9.

Images