CN102709589B - Lithium ion battery and electrolyte thereof - Google Patents

Abstract

The invention provides a lithium-ion battery with good high-temperature cycle performance, which includes: a cathode whose active material is LiFePO ₄ ; an anode; a separator placed between the cathode and the anode; and a non-aqueous electrolyte, and the electrolyte contains An aromatic compound as described in the structural formula, wherein the X group is selected from: one of S, O, and NR, and the R group in the NR is independently selected from one of H, alkyl, and amino; R ₁ , R ₂ , R ₃ , and R ₄ are independently chain substituents or are connected to each other to form a ring.

Description

Lithium-ion battery and its electrolyte

technical field

The invention relates to a lithium ion battery and a lithium ion battery electrolyte, in particular to a lithium iron phosphate battery and the electrolyte.

Background technique

Since the beginning of the 21st century, the number of cars in various countries in the world has increased day by day, making the earth's oil resources increasingly scarce and the pollution of the atmospheric environment increasingly serious. In this context, countries are actively carrying out research on green and environmentally friendly pure electric vehicles and hybrid vehicles, in order to deal with the increasingly severe problems of oil resources and environmental pollution.

Lithium-ion secondary batteries have become the preferred power source for power vehicles due to their high energy density, high capacity, good cycle performance and environmental protection. Whether power vehicles and hybrid vehicles can be widely used in daily life depends on the performance of power lithium-ion secondary batteries. As a power battery, it must have good high and low temperature performance, normal temperature cycle performance, long-term storage performance and safety performance.

LiFePO ₄ , a cathode material for lithium-ion batteries, has become a research hotspot for lithium-ion power batteries due to its high capacity, good cycle performance, stable structure, environmental friendliness, and cheap raw materials. When the power battery is actually used, because the battery itself will generate heat when it is discharged, the ambient temperature is generally relatively high (40-80°C). Under this condition, there are higher requirements for the high-temperature performance of the lithium iron phosphate power battery . At present, lithium iron phosphate batteries on the market are cycled at high temperatures, and the capacity decays quickly, and the high-temperature cycle performance cannot meet the requirements of power batteries.

Contents of the invention

In order to solve the above problems, the invention provides a lithium-ion battery with good high-temperature cycle performance, which includes:

_The active material is the cathode of LiFePO4;

anode;

a separator placed between the cathode and the anode; and

A non-aqueous electrolyte, and the electrolyte contains an aromatic compound as described in structural formula 1:

Wherein the X group is selected from: one of S, O, and NR, and the R group in the NR is independently selected from one of H, alkyl, and amino;

R ₁ , R ₂ , R ₃ , R ₄ are independently chain substituents or are connected to each other to form a ring;

When R ₁ , R ₂ , R ₃ , and R ₄ are connected to each other to form a ring, R ₁ and R ₃ , R ₁ and R ₂ , or R ₂ and R ₄ independently form a ring, and the ring is a 4-6-membered ring, The 4-6 membered ring is a cyclic hydrocarbon or a heterocyclic ring, the heterocyclic ring is a heterocyclic ring containing O, S or N, and the cyclic hydrocarbon is a cycloalkane, a cycloalkene or benzene;

The chain substituent is selected from hydrogen atom, halogen, alkyl group with 1 to 10 carbon atoms, alkoxy group with 1 to 10 carbon atoms, acyl group with 1 to 10 carbon atoms, and the number of carbon atoms is One of 2 to 10 alkenyl groups, nitro groups, thio groups, sulfonyl groups and phenyl groups, and the chain substituents are straight chain substituents or branched chain substituents;

The content of the aromatic compound described in structural formula 1 is 0.01-2% by weight based on the total weight of the electrolytic solution. When the content of the heterocyclic aromatic compound in the electrolyte is too small, it cannot form a conductive film on the surface of the positive electrode, and it will not have a protective effect; when the content of the heterocyclic aromatic compound in the electrolyte is too much, the internal resistance of the battery will be reduced accordingly. increase, the reversibility decreases, and the performance deteriorates.

More specifically, the heterocyclic aromatic compound represented by the structural formula 1 is preferably selected from one or more of the following structural formulas:

As a preferred solution of the present invention, the lithium-ion battery is made by the following chemical conversion method: the highest cut-off voltage of charge during the first 10 charges will be higher than the cut-off voltage of normal operation, and the highest cut-off voltage of charge is lower than 4.8V.

As a preferred version of the present invention, the non-aqueous electrolyte also contains one or more of the following additives: vinylene carbonate, vinyl ethylene carbonate, halogenated vinyl carbonate, cyclic sulfonate, cyclic ethylene Sulfate, cyclic sulfate.

As a preferred version of the present invention, the solvent in the non-aqueous electrolyte contains one or more of the following components: cyclic carbonate, chain carbonate and carboxylate;

Wherein the cyclic carbonate is one or more selected from: ethylene carbonate, propylene carbonate, butylene carbonate;

Chain carbonate or carboxylate is selected from one or more of: dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate;

The carboxylate is selected from one or more of γ-butyrolactone, ethyl acetate, ethyl propionate, methyl propionate and methyl butyrate.

As a preferred solution of the present invention, the active material of the anode is graphite.

The inventors found that under high temperature conditions, the main reasons for the rapid capacity decay of lithium iron phosphate batteries are: (1) the dissolution of Fe ions from the positive electrode. At a higher temperature (55°C), LiPF6 in the electrolyte is easily decomposed to produce HF and PF ₅ . Among them, HF will corrode the positive electrode, leading to the dissolution of Fe ions, thereby destroying the structure of the positive electrode material, resulting in capacity loss; (2) the reduction of Fe ions in the negative electrode. During the high-temperature cycle, the HF content in the electrolyte increases, resulting in an increase in the dissolution of Fe ions in the positive electrode. In this way, during the charge-discharge cycle, the dissolved Fe ions will be reduced to Fe simple substance on the SEI surface, making the impedance of the negative electrode become larger and larger as the charge-discharge progresses, leading to an increase in the irreversible capacity of the battery, and finally making the The performance of the battery is severely degraded. It can be said that under high temperature conditions, the dissolution of positive Fe ions has a destructive effect on the positive and negative electrodes. If the positive electrode film-forming additive is added to the electrolyte, the dissolution of Fe ions in the positive electrode at high temperature can be reduced to a certain extent, thereby improving the high-temperature cycle performance of the lithium iron phosphate battery.

After creative research, the inventor proposed to use thiophene, furan, pyrrole and their derivatives shown in structural formula 1 as positive electrode film-forming additives, allowing them to form a conductive polymer on the surface of the positive electrode active material lithium iron phosphate during the formation process The film inhibits the dissolution of Fe ions in lithium iron phosphate batteries at high temperatures, and significantly improves the high-temperature cycle performance of lithium iron phosphate batteries.

After adopting the above technical solution in the present invention, firstly, the heterocyclic aromatic compound shown in structural formula 1 is added to the electrolyte solution of conventional lithium iron phosphate power battery. The compound can be used as positive electrode film-forming additive in lithium-ion battery electrolyte. Because under a certain charging voltage, this type of compound will be oxidized and undergo electropolymerization, thereby forming a conductive polymer film on the surface of the positive electrode material of the lithium battery. The polymer film covers the surface of the positive electrode and prevents the reaction between the electrolyte and the positive electrode material. At a high temperature of 60°C, the content of free acid HF in the electrolyte is relatively high; the conductive film covering the surface of the positive electrode can reduce the corrosion effect of HF on the positive electrode and reduce the amount of Fe ions leached from the positive electrode at high temperature, thereby protecting the positive electrode. , reducing the loss of capacity; in addition, the dissolution of Fe ions in the positive electrode is suppressed, and the reduction of Fe ions on the surface of the negative electrode is also reduced to a certain extent, and the damage of the negative electrode in the high-temperature cycle is therefore suppressed to a certain extent, thereby improving the reversibility of the battery . Therefore, the heterocyclic aromatic compound represented by the structural formula 1 can effectively improve the high-temperature cycle performance of the lithium iron phosphate battery.

Furthermore, after the lithium iron phosphate battery in the present invention adopts the electrolyte in the above-mentioned technical solution, a specific formation method is adopted in the initial charging process of the battery: the highest charging cut-off voltage during the first 10 charging times is higher than that during normal operation. charging cut-off voltage, and the charging cut-off voltage is lower than 4.8V. The purpose is to enable the heterocyclic aromatic compound represented by structural formula 1 to form a better and more stable conductive film on the surface of the positive electrode, so as to further improve its high-temperature cycle performance.

In summary, after using the electrolyte of the present invention in a lithium-ion power battery with lithium iron phosphate as the positive electrode, it can overcome the lack of high-temperature performance of the current lithium iron phosphate battery and greatly improve its practicability in power batteries.

detailed description

In order to describe in detail the technical content, structural features, achieved objectives and effects of the present invention, the following will be described in detail in conjunction with the embodiments.

this invention

In order to describe the technical content, structural features, objectives and effects of the present invention in detail, the following will be described in detail in conjunction with the embodiments, but the present invention is not limited to the following examples.

Example 1

1) The electrolyte is prepared as follows: ethylene carbonate (EC) and ethyl methyl carbonate (EMC) are mixed in a volume ratio of EC:EMC=1:2, and lithium hexafluorophosphate (LiPF6) is added after mixing, The concentration is 1.0 mol/L, and thiophene is further added, and the content of thiophene is 0.5% based on the total weight of the electrolyte.

2) Negative electrode production: Mix negative active material modified natural graphite, conductive carbon black Super-P, binder styrene-butadiene rubber (SBR) and carboxymethyl cellulose (CMC) at a mass ratio of 94:1:2.5:2.5 , and then disperse them in deionized water to obtain negative electrode slurry. The slurry is coated on both sides of the copper foil, dried, calendered and vacuum dried, and a nickel lead wire is welded with an ultrasonic welder to obtain a negative plate, the thickness of which is 120-150 μm.

3) Positive electrode production: mix positive electrode active material lithium iron phosphate (LiFePO ₄ ), conductive carbon black Super-P and binder polyvinylidene fluoride (PVDF) at a mass ratio of 90:3:7, and then disperse them in N-methyl-2-pyrrolidone (NMP) to obtain positive electrode slurry. The slurry is uniformly coated on both sides of the aluminum foil, dried, calendered and vacuum-dried, and an aluminum lead-out wire is welded on by an ultrasonic welder to obtain a positive plate with a thickness of 120-150 μm.

4) Diaphragm production: use polypropylene/polyethylene/polypropylene three-layer isolation membrane with a thickness of 20 μm.

5) Preparation of battery cells Place a polyethylene microporous membrane with a thickness of 20 μm between the positive plate and the negative plate as a separator, then wind the sandwich structure composed of the positive plate, negative plate and separator, and then press the wound body After flattening, put it into a square aluminum metal shell, weld the lead wires of the positive and negative electrodes to the corresponding positions of the cover plate, and use a laser welding machine to weld the cover plate and the metal shell into one body to obtain the battery cell to be injected.

6) Liquid injection and formation of the battery core In a glove box with a dew point controlled below -40°C, inject the electrolyte solution prepared above into the battery core through the liquid injection hole, and the amount of electrolyte solution must fill the gaps in the battery core. Then carry out the routine formation of the first charge according to the following steps: 0.05C constant current charging for 3 minutes, 0.2C constant current charging for 5 minutes, 0.5C constant current charging for 25 minutes, shelving for 1 hour, shaping and sealing, and then further charging with a constant current of 0.2C to 3.65 V, after standing at room temperature for 24 hours, discharge to 2.0V with a constant current of 0.2C. In this patent, unless otherwise specified, all lithium iron phosphate batteries are formed according to this conventional formation method, and the required lithium ion batteries are obtained after the formation.

7) Cycling performance test at room temperature: At 25°C, the formed battery was charged to 3.65V with 1C constant current and constant voltage, and then discharged to 2.0V with 1C constant current. After charging/discharging 200 cycles, calculate the retention rate of the 200th cycle capacity.

200th cycle capacity retention rate (%) = (200th cycle discharge capacity / first cycle discharge capacity) × 100%

8) 60°C cycle performance test: At 60°C, the formed battery was charged to 3.65V with 1C constant current and constant voltage, and then discharged to 2.0V with 1C constant current. After charging/discharging 100 cycles, calculate the retention rate of the 100th cycle capacity.

The 100th cycle capacity retention rate (%) = (100th cycle discharge capacity / first cycle discharge capacity) × 100%

9) High-temperature storage performance: charge the formed battery to 3.65V with 1C constant current and constant voltage at room temperature, measure the initial thickness of the battery, and then store it at 60°C for 7 days, and finally wait for the battery to cool to room temperature before measuring the final thickness of the battery. Calculate the battery thickness expansion rate.

Battery thickness expansion rate (%)=((final thickness-initial thickness)/initial thickness)×100%

Example 2

The preparation method of the electrolyte and the lithium ion battery are the same as in Example 1, except that 0.5% of thiophene in the electrolyte is replaced with 0.5% of 2-methylthiophene. The data of 60°C cycle, room temperature cycle and high temperature storage obtained from the test are shown in Table 1.

Example 3

The preparation method of the electrolyte and the preparation method of the lithium ion battery are the same as those in Example 1, except that 0.5% of thiophene in the electrolyte is replaced with 0.5% of 2-acetylthiophene. The data of 60°C cycle, room temperature cycle and high temperature storage obtained from the test are shown in Table 1.

Example 4

The preparation method of the electrolyte and the preparation method of the lithium-ion battery are the same as those in Example 1, except that 0.5% of thiophene in the electrolyte is replaced with 0.5% of 3-methylthiophene. The data of 60°C cycle, room temperature cycle and high temperature storage obtained from the test are shown in Table 1.

Example 5

The preparation method of the electrolyte solution and the preparation method of the lithium ion battery are the same as those in Example 1, except that 0.5% thiophene in the electrolyte solution is replaced with 0.5% 3-ethylthiophene. The data of 60°C cycle, room temperature cycle and high temperature storage obtained from the test are shown in Table 1.

Example 6

The preparation method of the electrolyte solution and the preparation method of the lithium ion battery are the same as those in Example 1, except that 0.5% thiophene in the electrolyte solution is replaced with 0.5% 2-n-pentylthiophene. The data of 60°C cycle, room temperature cycle and high temperature storage obtained from the test are shown in Table 1.

Example 7

The preparation method of the electrolyte and the preparation method of the lithium ion battery are the same as those in Example 1, except that 0.5% of thiophene in the electrolyte is replaced with 0.5% of 3-octylthiophene. The data of 60°C cycle, room temperature cycle and high temperature storage obtained from the test are shown in Table 1.

Example 8

The preparation method of the electrolyte and the preparation method of the lithium-ion battery are the same as in Example 1, except that 0.5% of thiophene in the electrolyte is replaced with 0.5% of 3-decylthiophene. The data of 60°C cycle, room temperature cycle and high temperature storage obtained from the test are shown in Table 1.

Example 9

The preparation method of the electrolyte solution and the preparation method of the lithium ion battery are the same as those in Example 1, except that 0.5% thiophene in the electrolyte solution is replaced with 0.5% 3,4-ethylenedioxythiophene. The data of 60°C cycle, room temperature cycle and high temperature storage obtained from the test are shown in Table 1.

Example 10

The preparation method of the electrolyte solution and the preparation method of the lithium ion battery are the same as in Example 1, except that 0.5% thiophene in the electrolyte solution is replaced with 0.5% benzothiophene. The data of 60°C cycle, room temperature cycle and high temperature storage obtained from the test are shown in Table 1.

Example 11

The preparation method of the electrolyte and the preparation method of the lithium-ion battery are the same as in Example 1, except that 0.5% of thiophene in the electrolyte is replaced by 0.5% of furan. The data of 60°C cycle, room temperature cycle and high temperature storage obtained from the test are shown in Table 1.

Example 12

The preparation method of the electrolyte solution and the preparation method of the lithium-ion battery are the same as those in Example 1, except that 0.5% of thiophene in the electrolyte solution is replaced with 0.5% of 2-methylfuran. The data of 60°C cycle, room temperature cycle and high temperature storage obtained from the test are shown in Table 1.

Example 13

The preparation method of the electrolyte and the preparation method of the lithium ion battery are the same as those in Example 1, except that 0.5% of thiophene in the electrolyte is replaced by 0.5% of N-methylpyrrole. The data of 60°C cycle, room temperature cycle and high temperature storage obtained from the test are shown in Table 1.

Comparative example 1

The preparation method of the electrolyte and the preparation method of the lithium-ion battery are the same as in Example 1, except that no additives are added to the electrolyte. The data of 60°C cycle, room temperature cycle and high temperature storage obtained from the test are shown in Table 1.

Table 1 The data of 60°C cycle, normal temperature cycle and high temperature storage of Examples 1-13 and Comparative Example 1

Note: Conventional formation: In the first charge, 0.05C constant current charge for 3 minutes, 0.2C constant current charge for 5 minutes, 0.5C constant current charge for 25 minutes.

It can be seen from the data in Table 1 that the high-temperature cycle of the battery prepared with the addition of thiophene, thiophene derivatives, furan, furan derivatives, and N-methylpyrrole compared with the electrolyte without additives Performance and high-temperature storage performance are significantly improved, while normal temperature cycle performance is slightly improved.

Example 14

The preparation method of the electrolyte and the preparation method of the lithium-ion battery are the same as in Example 1, except that the content of thiophene in the electrolyte is replaced by 0.01%. The data of 60°C cycle, normal temperature cycle and high temperature storage obtained from the test are shown in Table 2.

Example 15

The preparation method of the electrolyte solution and the preparation method of the lithium-ion battery are the same as in Example 1, except that the content of thiophene in the electrolyte solution is replaced by 0.1%. The data of 60°C cycle, normal temperature cycle and high temperature storage obtained from the test are shown in Table 2.

Example 16

The preparation method of the electrolyte solution and the preparation method of the lithium-ion battery are the same as in Example 1, except that the content of thiophene in the electrolyte solution is replaced by 1%. The data of 60°C cycle, normal temperature cycle and high temperature storage obtained from the test are shown in Table 2.

Example 17

The preparation method of the electrolyte solution and the preparation method of the lithium-ion battery are the same as in Example 1, except that the content of thiophene in the electrolyte solution is replaced by 2%. The data of 60°C cycle, normal temperature cycle and high temperature storage obtained from the test are shown in Table 2.

Example 18

The preparation method of the electrolyte solution and the preparation method of the lithium ion battery are the same as in Example 1, except that the content of thiophene in the electrolyte solution is replaced by 3%. The data of 60°C cycle, normal temperature cycle and high temperature storage obtained from the test are shown in Table 2.

Table 2 The data of 60°C cycle, normal temperature cycle and high temperature storage of Examples 14-18

Note: Conventional formation: In the first charge, 0.05C constant current charge for 3 minutes, 0.2C constant current charge for 5 minutes, 0.5C constant current charge for 25 minutes.

As can be seen from the data in Table 2, when the content of thiophene increases from 0.01% to 2%, the high-temperature cycle performance and high-temperature storage performance gradually increase, and when the content increases from 1% to 2%, the high-temperature cycle performance and high-temperature storage performance The improvement range is small; but when the content increases from 2% to 5%, the performance of high-temperature cycle and high-temperature storage decreases very obviously.

Example 19

The preparation method of the electrolyte is the same as that of the lithium-ion battery in Example 1, and VEC is added to the electrolyte, and the content of VEC is 1% based on the total weight of the electrolyte. The data of 60°C cycle, room temperature cycle and high temperature storage obtained from the test are shown in Table 3.

Example 20

The preparation method of the electrolyte is the same as that of the lithium-ion battery in Example 1, and fluoroethylene carbonate (FEC) is added to the electrolyte, and the content of FEC is 1% based on the total weight of the electrolyte. The data of 60°C cycle, room temperature cycle and high temperature storage obtained from the test are shown in Table 3.

Example 21

The preparation method of the electrolyte is the same as that of the lithium ion battery in Example 1, and VC is added to the electrolyte, and the content of VC is 1% by the total weight of the electrolyte. The data of 60°C cycle, room temperature cycle and high temperature storage obtained from the test are shown in Table 3.

Example 22

The preparation method of the electrolyte solution and the preparation method of the lithium-ion battery are the same as those in Example 17, except that the conventional formation method is not used for the initial charging of the battery, but the following high-voltage formation method is used: first charge at 0.05C for 60 minutes, then charge at 0.2C to 4.2V, and finally at 4.2V constant voltage for 120min. The data of 60°C cycle, room temperature cycle and high temperature storage obtained from the test are shown in Table 3.

Comparative example 2

The preparation method of the electrolyte and the lithium ion battery are the same as in Example 1, except that 0.5% of thiophene in the electrolyte is replaced by 1% of VEC. The data of 60°C cycle, room temperature cycle and high temperature storage obtained from the test are shown in Table 3.

Comparative example 3

The preparation method of the electrolyte and the preparation method of the lithium-ion battery are the same as those in Example 1, except that 0.5% of thiophene in the electrolyte is replaced by 1% of FEC. The data of 60°C cycle, room temperature cycle and high temperature storage obtained from the test are shown in Table 3.

Comparative example 4

The preparation method of the electrolyte solution and the preparation method of the lithium ion battery are the same as those in Example 1, except that 0.5% thiophene in the electrolyte solution is replaced with 1% VC. The data of 60°C cycle, room temperature cycle and high temperature storage obtained from the test are shown in Table 3.

Table 3 The data of 60°C cycle, normal temperature cycle and high temperature storage of Examples 19-22 and Comparative Examples 2-4

Note: Conventional formation: In the first charge, charge at 0.05C constant current for 3 minutes, at 0.2C for 5 minutes, at 0.5C for 25 minutes; for high voltage formation: in the first charge, charge at 0.05C for 60 minutes, then charge at 0.2C to 4.2V, and finally at 4.2V constant voltage for 120min.

It can be seen from the data in Table 3 that on the basis of using VC, FEC or VEC, further adding thiophene can make the battery obtain better high-temperature cycle performance, high-temperature storage performance and normal temperature cycle performance; The method of voltage formation can further improve high-temperature cycle performance, high-temperature storage performance and normal-temperature cycle performance.

The above is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process conversion made by using the content of the description of the present invention, or directly or indirectly used in other related technical fields, shall be The same reasoning is included in the patent protection scope of the present invention.

Claims (4)

1. A lithium ion battery comprising: _The active material is the cathode of LiFePO4; anode; a separator placed between the cathode and the anode; and Non-aqueous electrolytic solution, described electrolytic solution comprises solvent and film-forming additive, and described film-forming additive is made up of aromatic compound as described in structural formula 1: Wherein the X group is selected from: one of S, O, and NR, and the R group in the NR is independently selected from one of H, alkyl, and amino; R ₁ , R ₂ , R ₃ , R ₄ are independently chain substituents or are connected to each other to form a ring; When R ₁ , R ₂ , R ₃ , and R ₄ are connected to each other to form a ring, R ₁ and R ₃ , R ₁ and R ₂ , or R ₂ and R ₄ independently form a ring, and the ring is a 4-6-membered ring, The 4-6 membered ring is a cyclic hydrocarbon or a heterocyclic ring, the heterocyclic ring is a heterocyclic ring containing O, S or N, and the cyclic hydrocarbon is a cycloalkane, a cycloalkene or benzene; The chain substituents are selected from halogen, alkyl groups with 1 to 10 carbon atoms, alkoxy groups with 1 to 10 carbon atoms, acyl groups with 1 to 10 carbon atoms, and 2 to 10 carbon atoms One of alkenyl, nitro, thio, sulfonyl and phenyl, the chain substituent is a straight chain substituent or a branched chain substituent; The content of the aromatic compound described in structural formula 1 is 0.5-2% by weight based on the total weight of the electrolyte; The solvent in the non-aqueous electrolytic solution is composed of one or more of the following components: cyclic carbonate, chain carbonate and carboxylate; Wherein the cyclic carbonate is selected from one or more of: ethylene carbonate, propylene carbonate, butylene carbonate; Chain carbonate is selected from: one or more of dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, and propyl methyl carbonate; The carboxylate is selected from one or more of γ-butyrolactone, ethyl acetate, ethyl propionate, methyl propionate, and methyl butyrate; The lithium-ion battery is prepared by the following chemical conversion method: the highest cut-off voltage of charging in the first 10 times of charging is higher than that in normal operation, and the highest cut-off voltage of charging is lower than 4.8V. 2. Lithium-ion battery according to claim 1, is characterized in that, described non-aqueous electrolytic solution also comprises one or more of following additives: vinylene carbonate, vinyl vinyl carbonate, halogenated vinyl carbonate , Cyclic sulfonate, cyclic sulfite, cyclic sulfate. 3. The lithium ion battery according to claim 1, wherein the active material of the anode is graphite. 4. according to the nonaqueous electrolytic solution used in any one lithium ion battery of claim 1 to 3.