CN114142093A - Ternary high-voltage lithium ion battery electrolyte additive, electrolyte containing additive and lithium ion battery - Google Patents
Ternary high-voltage lithium ion battery electrolyte additive, electrolyte containing additive and lithium ion battery Download PDFInfo
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- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
- H01M10/0564—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of organic materials only
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- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
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Abstract
The invention discloses a high-voltage electrolyte additive for a lithium ion battery, a high-voltage electrolyte containing the additive and the lithium ion battery. The additive is a benzene polynitrile compound with a structure shown in a structural formula I:
wherein R is1、R2Each independently selected from hydrogen, cyano, halogen, C1~C6With hydrocarbon radicals, some or all of the hydrogens being replaced by halogens1~C6A hydrocarbon group of1~C6Alkoxy, part or all of the hydrogen of (A) are replaced by halogenSubstituted C1~C6One or more of the alkoxy groups of (a). The electrolyte additive can effectively promote the polymerization of the surface of the anode of the lithium ion battery to form a stable CEI film, inhibit the interface reaction of the anode and the electrolyte, and reduce the oxidative decomposition of the electrolyte in a high-voltage environment, thereby effectively improving the cycle performance and the service life of the lithium ion battery under normal voltage and high voltage. Meanwhile, the electrolyte has simple preparation process and wide application prospect, and is suitable for industrial production.
Description
Technical Field
The invention belongs to the technical field of lithium ion batteries, and particularly relates to an electrolyte additive capable of improving the cycle performance and the service life of a lithium ion battery at 3-4.6V, an electrolyte containing the additive and the lithium ion battery.
Background
The lithium ion battery has the characteristics of high working voltage, large energy density, long cycle life and the like, and is widely applied to the fields of 3C digital products, electric automobiles, aerospace and the like. In recent years, with the development of electronic products towards intellectualization, long endurance and multiple functions, the market puts higher demands on the energy density of lithium ion batteries.
At present, two types of power batteries in the field of new energy automobiles are mainly used, one type is a lithium iron phosphate battery, and the other type is a ternary material battery. Compared with lithium iron phosphate materials, ternary materials have higher conductivity and theoretical and actual gram-capacity, and therefore are receiving more and more attention from the market. In order to improve the energy density of the ternary material battery, besides the improvement of the existing ternary cathode material and battery preparation process, the increase of the charge cut-off voltage of the battery is a common measure, and the high energy density of the battery is realized by increasing the charge depth of the cathode active material.
However, with the increase of the voltage of the lithium ion battery, the conventional electrolyte is easily oxidized and decomposed by the anode active material under high voltage to generate a large amount of gas, and meanwhile, the products of the oxidative decomposition of the electrolyte are continuously deposited on the surface of the anode, so that the internal resistance and the thickness of a passivation layer of the battery are continuously increased, and the cycle performance of the battery is deteriorated; in addition, the positive active material is unstable under high voltage, and under the action of the electrolyte, transition metal ions are reduced and dissolved out, and reduced into a metal simple substance on the surface of the negative electrode after passing through the SEI film, so that the impedance of the negative electrode is continuously increased, and the service life of the battery under high voltage is seriously shortened.
The problem of the matching property of the electrolyte seriously hinders the development of the high-voltage lithium ion battery; therefore, it is urgently needed to develop an electrolyte suitable for a high voltage of more than 4.4V so as to ensure that the performance of the lithium ion battery anode material system is well exerted.
Nowadays, adding electrolyte additives to conventional electrolytes is the most effective and convenient method for improving electrolyte performance of buried ion batteries. Nitriles are organic compounds containing cyano groups in molecular structures, and can enhance the resistance of the electrolyte to anode oxidation, so that the cycle life of the electrolyte under high voltage is prolonged. Most of nitrile additives currently studied are straight-chain polynitriles, such as Adiponitrile (AN) disclosed in Chinese patent CN 105633469B and Succinonitrile (SN) disclosed in patent CN 105098246B. Chinese patent publication No. CN 107785610A proposes the use of benzonitrile compound as an additive to prepare a lithium ion battery, but the addition of benzonitrile compound only improves the high/low temperature performance of the lithium ion battery, and does not mention the improvement of the high voltage resistance of the battery. Chinese patent publication No. CN 108390097A discloses a lithium ion battery prepared by using benzonitrile as an additive, and the high voltage stability of the lithium ion battery at a voltage of 4.5V is improved. Since the high voltage resistance of the battery is improved by the nitrile additives in relation to the number of-C ≡ N functional groups in the molecule, the higher the number of-C ≡ N functional groups in a single molecule, the more the complex with the transition metal ion can be achieved at a proper addition amount. This makes it possible to achieve the effect of the other mononitriles in a relatively large amount with a relatively small amount of polynitriles. Obviously, in the chinese patent with publication No. CN 108390097A, the number of cyano groups in benzonitrile is small, the dosage of the additive is large (the mass percentage is up to 10-20%), an excessively thick positive electrode interface film is formed, the conductivity of the lithium ion battery is reduced, and the cycle performance of the lithium ion battery is affected; in addition, the addition of the additive in an excessively large amount sharply increases the manufacturing cost of the electrolyte. Therefore, the invention aims to develop a benzonitrile additive with more-C.ident.N functional groups in a single molecule and a nonaqueous lithium ion battery electrolyte based on the additive; the addition amount is less (0.3-1% by mass) and the cost is lower, so that the cycling stability of the lithium ion battery under the voltage of more than 4.5V is further improved, and the lithium ion battery has a practical application prospect.
Disclosure of Invention
One of the objects of the present invention is: the additive for the lithium ion battery electrolyte can effectively inhibit the oxidative decomposition of the electrolyte and the dissolution of the transition metal of the positive electrode, has good film forming characteristics at the positive electrode and the negative electrode, and can effectively improve the cycle performance of the lithium ion battery under high voltage.
The second purpose of the invention is: the electrolyte additive for the lithium ion battery contains the electrolyte additive, effectively inhibits the oxidative decomposition of the electrolyte and the dissolution of the transition metal of the anode, and improves the cycle performance of the lithium ion battery under high voltage.
The third purpose of the invention is that: the lithium ion battery containing the electrolyte is provided, so that the cycle performance under high voltage is obviously improved.
In order to achieve the above object, the present invention is a non-aqueous electrolyte for a high voltage lithium ion battery comprising a non-aqueous organic solvent, an electrolyte lithium salt and an additive, wherein the additive comprises a conventional additive and an additive represented by the structural formula i:
wherein R is1、R2Is any one of the following cases:
hydrogen atoms, part of the hydrogen or all of the hydrogen is replaced by halogen, cyano, benzyl;
a straight chain hydrocarbon group having 1 to 6 carbon atoms;
c with some or all of the hydrogens replaced by halogens1 ~ C6A hydrocarbon group of (a);
an alkoxy group having 1 to 6 carbon atoms;
c with some or all of the hydrogens replaced by halogens1 ~ C6An alkoxy group of (a).
Specifically, structural formula I includes, but is not limited to, any of the following structural formulae:
preferably, the content of the electrolyte additive accounts for 0.3-1% of the total mass of the electrolyte.
The invention also provides a high-voltage electrolyte containing the electrolyte additive, wherein the high voltage is 4.4-4.6V, and the high-voltage electrolyte additive is added into the conventional electrolyte to prepare the high-voltage electrolyte; the conventional electrolyte includes a non-aqueous organic solvent, an electrolytic lithium salt, and a conventional electrolyte additive.
In the present invention, the conventional additives include any one or more of fluoroethylene carbonate (FEC), ether Trinitrile (TCEP), Succinonitrile (SN), Adiponitrile (ADN), 1,3, 6-Hexanetricarbonitrile (HTN), p-fluorobenzonitrile, p-methylbenzonitrile, 1,3, 5-pentanetrimethylnitrile, 2-methylmaleic anhydride (citraconic anhydride), tributyl phosphate (TPP), ethylene glycol bis (propionitrile) ether (done).
In the present invention, the non-aqueous organic solvent comprises one or more of Ethylene Carbonate (EC), Propylene Carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), Ethyl Methyl Carbonate (EMC), dimethylformamide, diethylformamide, dimethyl sulfite, vinylene carbonate, methyl propyl carbonate, tetrahydrofuran, propylene oxide, ethyl acetate, methyl butyrate, ethyl butyrate, methyl propionate, ethyl propionate, and propyl acetate.
Preferably, the content of the non-aqueous organic solvent accounts for 80-90% of the total mass of the electrolyte, more preferably, the non-aqueous organic solvent is a combination of Ethylene Carbonate (EC) and diethyl carbonate (DEC), and the mass ratio of the ethylene carbonate to the diethyl carbonate is (20-30): 50-60), for example, 20:60 are mixed.
In the present invention, the electrolyte lithium salt includes lithium hexafluorophosphate (LiPF)6) Lithium hexafluoroarsenate (LiAsF)6) Lithium perchlorate (LiClO)4) Lithium tetrafluoroborate (LiBF)4) Lithium bis (oxalato) borate (LiBOB), lithium bis (oxalato) borate (LiDFOB), lithium methyl sulfonate (LiCH)3SO3) Lithium trifluoromethanesulfonate (LiCF)3SO3) One or more of them.
Preferably, the content of the electrolyte lithium salt accounts for 10-15% of the total mass of the electrolyte, more preferably, the electrolyte lithium salt accounts for 13.5% of the mass fraction of lithium hexafluorophosphate (LiPF) with the concentration of 1M6）。
On the other hand, in order to achieve the purpose of the invention, the invention also provides a high-voltage lithium ion battery which comprises a battery cell formed by laminating or winding a positive plate, a diaphragm and a negative plate and the high-voltage resistant lithium ion battery nonaqueous electrolyte.
Preferably, the positive electrode active material of the positive electrode sheet is LiNi1-x-y-zCoxMnyAlzO2, wherein: x is more than or equal to 0 and less than or equal to 1, y is more than or equal to 0 and less than or equal to 1, z is more than or equal to 0 and less than or equal to 1, and x + y + z is more than or equal to 0 and less than or equal to 1; the negative electrode material active substance of the negative electrode plate is natural graphite, artificial graphite or SiOwThe silicon-carbon composite material is compounded with graphite, wherein w is more than 1 and less than 2.
Further preferably, the preparation method of the positive plate comprises the following steps: LiNi as positive electrode active material0.6Co0.1Mn0.3O2Or LiNi0.7Co0.1Mn0.2O2The conductive agent acetylene black and the binder polyvinylidene fluoride (PVDF) are mixed according to the mass ratio of 96: 2: 2, fully stirring and uniformly mixing in an N-methyl pyrrolidone solvent system, coating on an aluminum foil, drying and cold pressing to obtain a positive plate; the preparation method of the negative active material comprises the following steps: the negative active material artificial graphite, the conductive agent acetylene black, the binder Styrene Butadiene Rubber (SBR) and the thickener sodium carboxymethyl cellulose (CMC) are mixed according to the massAnd (3) comparing 96: 2: 1: 1, fully stirring and uniformly mixing in a deionized water solvent system, coating on a copper foil, drying, and cold pressing to obtain the negative plate.
In the invention, the charge cut-off voltage of the high-voltage lithium ion battery is greater than or equal to 4.4V.
The fluoroethylene carbonate (FEC) which is a conventional additive selected in the electrolyte can be decomposed on the surface of a negative electrode to form a layer of uniform and compact protective film, so that the active contact of an electrode material and the electrolyte is reduced, the microstructure of the electrode material is stabilized, and the cycle performance and the high-temperature performance of the high-voltage lithium ion battery are improved; meanwhile, the formed solid electrolyte membrane has low impedance, and is beneficial to improving the internal dynamic characteristics of the lithium ion battery.
In addition, the additive shown in the structural formula I is added, cyano-group in the benzonitrile can generate a complex reaction with transition metal ions on the surface of the active substance of the positive electrode, and benzene is polymerized on the positive electrode to form a layer of uniform and compact protective film, so that Li of the positive electrode is reduced+The phenomenon of uneven embedding is avoided, the corrosion of HF on NCM particles is inhibited, and the dissolution of transition metal elements at high temperature is reduced; meanwhile, the additive can be reduced on the surface of the cathode material (the reduction potential is 1.63V vs Li)+Li) to form a compact and stable SEI film, and reduce the oxidative decomposition of the electrolyte on the surface of the cathode material.
Therefore, the additive shown in the structural formula I is added into the conventional electrolyte additive, so that a film can be formed on the surface of the anode material, cracks in particles of the anode material are inhibited from being generated in the circulation process, the dissolution of transition metal elements at high temperature is reduced, an SEI film can be formed on the surface of the cathode material, the reduction reaction of a solvent at a cathode interface is inhibited, and the cycle performance and the service life of the lithium ion battery at high voltage are effectively improved.
Detailed Description
In order to make the purpose and advantages of the invention more clear; the technical content of the present invention will be further described below with reference to specific embodiments. It is to be understood that the following description is only intended to illustrate the present invention; the invention may be embodied in many other forms and is not limited to the embodiments described herein.
Example 1:
1. preparing an electrolyte: ethylene Carbonate (EC), dimethyl carbonate (DEC), and fluoroethylene carbonate (FEC) were mixed at a mass ratio of EC: DEC: FEC = 20:60:10, and 1M lithium hexafluorophosphate (LiPF) was added after mixing6) After the lithium salt is completely dissolved, a compound I with the mass fraction of 0.3 percent is added.
2. Preparing a positive plate: LiNi as positive electrode active material0.6Co0.1Mn0.3O2The conductive agent acetylene black and the binder polyvinylidene fluoride (PVDF) are mixed according to the mass ratio of 96: 2: 2, fully stirring and uniformly mixing in an N-methyl pyrrolidone solvent system, coating on an aluminum foil, drying, and cold pressing to obtain the positive plate.
3. Preparing a negative plate: preparing negative active material artificial graphite, conductive agent acetylene black, binder Styrene Butadiene Rubber (SBR), and thickener carboxymethylcellulose sodium (CMC) according to a mass ratio of 96: 2: 1: 1, fully stirring and uniformly mixing in a deionized water solvent system, coating on a copper foil, drying, and cold pressing to obtain the negative plate.
4. Preparing a lithium ion battery: and sequentially laminating the positive plate, the isolating membrane and the negative plate prepared by the process, winding the positive plate, the isolating membrane and the negative plate along the same direction to obtain a bare cell, placing the bare cell in an external package, standing the bare cell at 75 ℃ for 10 hours, injecting the prepared electrolyte and packaging. Standing for 24 hours, charging to 4.45V by using a constant current of 0.lC, and then charging to 0.05C by using a constant voltage of 4.45V; then discharging to 3.0V at 0.2C, and repeating the charging and discharging for 2 times; and finally, charging the battery to 3.8V at 0.2C to finish the battery manufacturing, thereby obtaining the high-voltage lithium ion battery.
Examples 2 to 9 and comparative examples 1 to 5
The electrolyte solution preparation methods of examples 2 to 9 and comparative examples 1 to 5 were carried out in accordance with the preparation method of example 1, and the electrolyte solution composition of examples 2 to 9 and comparative examples 1 to 5 are shown in table one. Meanwhile, the electrolytes prepared in examples 2 to 9 and comparative examples 1 to 5 were used to prepare a lithium ion battery according to the method for preparing the battery in example 1, and the performance of the lithium ion battery was tested, and the test method and the results are shown in table two.
Table one: the electrolyte compositions of examples 1-9 and comparative examples 1-5
Battery performance testing
The lithium ion batteries assembled with the illustrated electrolytes of examples 1-9 and comparative examples 1-5 were subjected to the following performance tests, respectively.
1. And (3) testing the cycle performance of the battery: the lithium ion batteries of the examples and comparative examples after capacity grading were constant-current charged at 0.5C to 4.6V at room temperature of 25 ± 2 ℃, then constant-voltage charged to an off-current of 0.01C, and left to stand for five minutes. Constant current discharge was carried out to 3.0V at 0.5C, and the first cycle discharge capacity was recorded. After the lithium ion battery is charged and discharged for 200 times in a circulating way, calculating the first charging and discharging efficiency and the capacity retention rate of the lithium ion battery under the high-voltage condition after 200 times of circulation according to the following formulas:
capacity retention ratio (%) at 200 cycles = (200 th cycle discharge capacity/1 st cycle discharge capacity) × 100%
2. High-temperature storage performance test: the lithium ion battery was charged and discharged at a rate of 0.5C/0.5C under a normal temperature (25 ℃), and the discharge capacity was represented as C0) Then, the lithium ion battery is charged to 4.6V at a constant current of 0.5C; the battery is placed in a heat preservation box at 80 ℃ for 8 hours, and after being taken out, the battery is cooled to normal temperature and is discharged to 3.0V at 0.5C (the discharge capacity is marked as C)1) (ii) a Finally, the lithium ion battery is charged and discharged at normal temperature at 0.5C/0.5C (the discharge capacity is marked as C)2) Calculating the capacity retention rate and the capacity recovery rate of the lithium ion battery under the high-temperature condition by using the following formulas:
capacity retention rate = (C)1/C0）×100%
Capacity recovery rate = (C)2/C0）×100%
Table two: results of cell performance test for examples 1 to 9 and comparative examples 1 to 5
As can be seen from the comparison of the results of the cell performance tests of examples 1-9 and comparative examples 2-5 in Table II: the additive with the structure shown in the structural formula I can obviously improve the high-voltage cycle performance and the capacity retention rate after high-temperature storage of the lithium ion battery. The first charge and discharge efficiency of examples 1 to 9 was low, indicating that the additive formed a protective film on the surface of the positive electrode material (part of active lithium in the electrolyte was consumed in this process) to inhibit the corrosion of HF to the active material particles, and to reduce the elution of transition metal elements at high voltage.
As can be seen from the comparison of the results of the cell performance tests of example 3 and comparative examples 2-5 in Table II: the battery cycle capacity is higher than that of the comparative examples 2-4 in normal temperature or high temperature environment no matter what conventional solvent system is added. Illustrating the use of the additive and its electrolyte; compared with the conventional additives used at present, the lithium ion battery has better cycle performance and high-temperature discharge performance both at normal temperature and high temperature.
As can be seen from the comparison of comparative example 2 with the results of the cell performance tests of examples 1-3 in Table 2: the addition amount of the additive is 0.3-1.0%, and the addition amounts in other ranges can not reach the high-voltage performance in the invention; when the addition amount of the additive is too small, the passivation layer formed on the surface of the positive electrode material by the substances is not stable enough; when the addition amount exceeds the addition amount of the additive, the passivation layer is too thick, the impedance is increased, and the electrochemical performance of the high-voltage lithium ion battery is deteriorated.
As can be seen from the comparison of the results of the cell performance tests of comparative examples 1-2 and example 3 in Table 2: the invention uses the common effect of the conventional negative film-forming additive FEC and the structural additive shown in the compound I; namely, a film is formed on the surface of the anode material, so that the generation of surface cracks of anode material particles in the circulation process is inhibited, and the dissolution of transition metal elements is reduced; and an SEI film can be formed on the surface of the negative electrode to inhibit the solvent from being reduced on the negative electrode, so that the cycle performance and the high-temperature storage performance of the high-voltage lithium ion battery are synergistically improved.
From the results of the comparison of the cell performances of comparative examples 2 to 3, it can be seen that: when FEC is added, the normal temperature performance of the battery is obviously improved, but the high temperature cycle performance is reduced. This is because the SEI film formed by FEC on the surface of the negative electrode is thin and dense; is stable under normal temperature cycle but not stable enough under high temperature, and can react with Mn ions and Ni ions dissolved out from the positive electrode. The benzenepolynitrile compound in the additive of comparative example 1 according to the present invention has a significant improvement in cycle performance and storage performance at high temperature.
The invention adopts a new lithium ion battery electrolyte additive which contains more cyano groups and generates complex reaction with different transition metal elements in the anode active substance respectively to polymerize benzene on the surface of the anode to form a stable interface film, and the chemical stability of the benzene ring compound can reduce the surface activity of the anode and further improve the stability of the anode/electrolyte interface. Thereby inhibiting the oxidative decomposition and cyclic gas generation of the electrolyte under the high-temperature and high-voltage environment. The tests show that the lithium ion battery adopting the electrolyte containing the additive can normally work in a high voltage range of 4.6V, and effectively meets the increasing voltage requirement of the lithium ion battery.
The above description is only specific to some embodiments of the present invention, and does not limit the scope of the invention of the present patent in any way; any alterations, modifications and improvements within the spirit and scope of the invention will occur to those skilled in the art from a consideration of the specification and the appended claims.
Claims (9)
1. The high-voltage electrolyte additive for the lithium ion battery is characterized in that: the electrolyte additive is benzene polynitrile C8H4N2Or one of its derivatives, having the following structural formula:
wherein R is1、R2Each independently selected from hydrogen, halogen, cyano, C1 ~ C6With hydrocarbon radicals, part or all of the hydrogen atoms being replaced by halogensSubstituted C1 ~ C6A hydrocarbon group of1 ~ C6Alkoxy, part or all of the hydrogens of (A) are replaced by halogen1 ~ C6Any one or more of the alkoxy groups of (a).
2. A high-voltage electrolyte of a lithium ion battery containing an electrolyte additive is characterized in that the high voltage is 4.4V-4.6V: adding the high voltage electrolyte additive of claim 1 to a conventional electrolyte; the conventional electrolyte comprises a non-aqueous organic solvent, a lithium salt and a conventional electrolyte additive; wherein, the content of the non-aqueous organic solvent accounts for 80-90% of the total mass of the electrolyte, and the content of the high-voltage electrolyte additive accounts for 0.3-1% of the total mass of the electrolyte.
3. The electrolyte of claim 2, wherein: the high voltage electrolyte additive of claim 1, wherein the additive is present in an amount of 0.3% to 1% by weight of the total electrolyte.
4. The electrolyte of claim 2, wherein: the non-aqueous organic solvent is mainly any one or a mixture of several of Ethylene Carbonate (EC), Propylene Carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), Ethyl Methyl Carbonate (EMC), dimethylformamide, diethylformamide, dimethyl sulfite, vinylene carbonate, methyl propyl carbonate, tetrahydrofuran, propylene oxide, ethyl acetate, methyl butyrate, ethyl butyrate, methyl propionate, ethyl propionate and propyl acetate.
5. The electrolyte of claim 2, wherein: the lithium salt is lithium hexafluorophosphate (LiPF)6) Lithium hexafluoroarsenate (LiAsF)6) Lithium perchlorate (LiClO)4) Lithium tetrafluoroborate (LiBF)4) Lithium bis (oxalato) borate (LiBOB), lithium bis (oxalato) borate (LiDFOB), lithium methyl sulfonate (LiCH)3SO3) Lithium trifluoromethanesulfonate (LiCF)3SO3) Any one or a mixture of several of themAn agent; the lithium salt accounts for 10-15% of the total mass of the lithium ion battery electrolyte.
6. The high voltage lithium ion battery electrolyte of claim 2, wherein: the lithium salt is lithium hexafluorophosphate with the concentration of 1M.
7. The electrolyte of claim 2, wherein: the conventional additive of the electrolyte is one or a mixture of several of fluoroethylene carbonate (FEC), ether Trinitrile (TCEP), Succinonitrile (SN), Adiponitrile (ADN), 1,3, 6-Hexanetricarbonitrile (HTN), p-fluorobenzonitrile, p-methylbenzonitrile, 1,3, 5-pentanetrimethyl nitrile, 2-methyl maleic anhydride (citraconic anhydride), tributyl phosphate (TPP) and ethylene glycol bis (propionitrile) ether (DENE).
8. A high voltage lithium ion battery, characterized by: the high-voltage lithium ion battery comprises a battery core formed by laminating or winding a positive plate, an isolating membrane and a negative plate, and the high-voltage electrolyte containing the additive is used as the electrolyte in any one of claims 1 to 7, wherein the charge cut-off voltage of the lithium ion battery is 4.4-4.6V.
9. The high voltage lithium ion battery of claim 8, wherein: the positive active material of the positive plate is LiNi1-x-y-zCoxMnyAlzO2, wherein: x is more than or equal to 0 and less than or equal to 1, y is more than or equal to 0 and less than or equal to 1, z is more than or equal to 0 and less than or equal to 1, and x + y + z is more than or equal to 0 and less than or equal to 1; the negative electrode material active substance of the negative electrode plate is natural graphite, artificial graphite or SiOwThe silicon-carbon composite material is compounded with graphite, wherein w is more than 1 and less than 2.
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| CN117239230A (en) * | 2022-10-12 | 2023-12-15 | 哈尔滨工业大学 | Lithium ion battery electrolyte additive, lithium ion battery electrolyte and preparation method of lithium ion battery electrolyte additive |
| CN117239230B (en) * | 2022-10-12 | 2024-06-04 | 哈尔滨工业大学 | Lithium ion battery electrolyte additive, lithium ion battery electrolyte and preparation method of lithium ion battery electrolyte additive |
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| CN117239230A (en) * | 2022-10-12 | 2023-12-15 | 哈尔滨工业大学 | Lithium ion battery electrolyte additive, lithium ion battery electrolyte and preparation method of lithium ion battery electrolyte additive |
| CN117239230B (en) * | 2022-10-12 | 2024-06-04 | 哈尔滨工业大学 | Lithium ion battery electrolyte additive, lithium ion battery electrolyte and preparation method of lithium ion battery electrolyte additive |
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