420 results about "Vinylene carbonate" patented technology

The invention relates to a battery monomer, a battery device and a power utilization device, the battery monomer comprises an electrode assembly and an electrolyte, and the electrode assembly comprises a positive pole piece and a negative pole piece; the positive pole piece comprises a positive pole current collecting part and a positive pole film layer; the positive pole film layer comprises lithium-containing phosphate with an olivine structure; the negative pole piece comprises a negative pole current collecting part and a negative pole film layer, and the negative pole film layer comprises a carbon-based material; the electrolyte comprises a carboxylic ester solvent, a first additive and fluorine-containing lithium sulfimide, and the mass content of the carboxylic ester solvent is 8%-60%; the total mass content of the first additive is 2.5%-10%, the first additive comprises 1, 3-propane sultone with the mass content larger than or equal to 0, an ethylene carbonate derivative with the mass content larger than or equal to 0 and vinylene carbonate with the mass content larger than 0, and the ethylene carbonate derivative comprises a compound shown in the formula A; the mass content of the fluorine-containing lithium sulfimide is 4%-8%. According to the invention, the rapid charging performance and the cycle performance of the battery monomer can be improved. # imgabs0 # formula A

The invention relates to a battery monomer, a battery device and a power utilization device, the battery monomer comprises an electrode assembly and an electrolyte, and the electrode assembly comprises a positive pole piece and a negative pole piece; the positive pole piece comprises lithium-containing phosphate with an olivine structure; the negative pole piece comprises graphite particles; the electrolyte comprises a carboxylic ester solvent and a first additive, the thickness of the single-side negative electrode film layer is 50 microns to 75 microns, and the volume average particle size of the graphite particles is 8.5 microns to 13.5 microns; based on the mass of the electrolyte, the mass content of the carboxylic ester solvent is 8%-60%, the total mass content of the first additive is 3%-10%, the first additive comprises 1, 3-propane sultone with the mass content larger than or equal to 0, an ethylene carbonate derivative with the mass content larger than or equal to 0 and vinylene carbonate with the mass content larger than or equal to 3%, and the ethylene carbonate derivative comprises a compound shown in the formula A. According to the invention, the rapid charging performance and the cycle performance of the battery monomer under high energy density can be improved. # imgabs0 # formula A

The invention provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises an electrode assembly, wherein the electrode assembly comprises a positive plate, a negative plate and a non-aqueous electrolyte; the positive plate comprises a positive current collector and a positive film layer, and the negative plate comprises a negative current collector and a negative film layer; the positive electrode film layer comprises a positive electrode active material, and the positive electrode active material comprises a lithium manganese iron phosphate material and a nickel cobalt lithium manganate material; in the nickel cobalt lithium manganate material, the molar ratio of Ni in the sum of the three elements of Ni, Co and Mn is 0.5-0.95; the non-aqueous electrolyte comprises vinylene carbonate, and the mass content of the vinylene carbonate in the non-aqueous electrolyte is 0.5%-2%; the non-aqueous electrolyte comprises at least one of linear carbonic ester and linear carboxylic ester, and the conductivity of the non-aqueous electrolyte is 9-14 mS / cm. The energy density, the cycle performance and the power performance of the battery monomer are improved at the same time.

The invention provides a lithium manganese iron phosphate battery. The battery comprises a positive pole piece, a negative pole piece and a non-aqueous electrolyte, the positive pole piece comprises a positive active material and a positive active coating arranged on at least one surface of the positive active material; the positive electrode active material comprises lithium manganese iron phosphate LiMnxFe1-xPO4 coated with a carbon coating layer, and x is more than or equal to 0.5 and less than or equal to 0.8; the negative pole piece comprises a negative active material and a negative active coating arranged on at least one surface of the negative active material; the battery satisfies the following relational expressions: 4.5 < = (a / 20 + d) / (b + c) < = 12.8; a is a coated diaphragm resistor of the positive pole piece; b is the compaction density of the positive pole piece; c is the mass percentage content of vinylene carbonate in the positive electrode slurry; and d is the mass percentage content of the lithium bis (fluorosulfonyl) imide in the non-aqueous electrolyte. By optimizing the composition of the lithium ion battery, the low-temperature discharge performance of the battery is improved, and meanwhile, the high-temperature cycle performance is considered.

The invention provides a lithium ion battery. The lithium ion battery comprises a positive pole piece and an electrolyte, the positive pole piece comprises a positive active material lithium iron phosphate; the electrolyte comprises an additive a and an additive b, the additive a comprises vinylene carbonate; the additive b comprises a compound with a structure as shown in a formula (I) and a compound with a structure as shown in a formula (II). Two additives are used in cooperation, VC is partially replaced, the addition amount of VC is reduced, and compared with SEI formed by VC reduction, SEI structures formed by the compound with the structure shown in the formula (I) and the compound with the structure shown in the formula (II) are more compact, the effect of inhibiting interface side reactions is stronger, and the effect of improving high-temperature circulation is better compared with VC. # imgabs0 #

The invention provides a battery monomer, a battery device and a power utilization device. The battery monomer comprises an electrode assembly, wherein the electrode assembly comprises a positive plate, a negative plate and a non-aqueous electrolyte; the positive pole piece comprises a positive current collector and a positive film layer, and the negative pole piece comprises a negative current collector and a negative film layer; wherein the positive electrode film layer comprises a positive electrode active material, and the positive electrode active material comprises a lithium iron phosphate material and a nickel cobalt lithium manganate material; in the positive electrode active material, the molar ratio of the Ni element to the sum of the three elements of Ni, Co and Mn is 0.5-0.95; the non-aqueous electrolyte comprises vinylene carbonate, and the mass content of the vinylene carbonate in the non-aqueous electrolyte is 0.5%-2%; the non-aqueous electrolyte comprises at least one of linear carbonic ester and linear carboxylic ester, and the conductivity of the non-aqueous electrolyte is 9-14 mS / cm. The energy density, the cycle performance and the power performance of the battery monomer are improved at the same time.

The invention provides a non-aqueous electrolyte, a lithium ion battery, a battery module, a battery pack and a power utilization device, the non-aqueous electrolyte comprises a lithium salt, an organic solvent and an electrolyte additive, and the electrolyte additive comprises 1, 3-propane sultone, fluoroethylene carbonate, vinylene carbonate, lithium tetrafluoroborate and a compound I shown in the formula I. The non-aqueous electrolyte is applied to the lithium ion battery, and the cycle life of the lithium ion battery is prolonged.

The invention relates to a battery monomer, a battery device and a power utilization device, the battery monomer comprises an electrode assembly and an electrolyte, the electrode assembly comprises a positive pole piece, the positive pole piece comprises a positive active material layer, and the positive active material layer comprises lithium-containing phosphate of an olivine structure; the electrolyte comprises, by mass, 8-30% of a carboxylic ester solvent, a lithium salt and an unsaturated ester additive, the lithium salt comprises lithium hexafluorophosphate and fluorine-containing lithium sulfimide, the mass content of the fluorine-containing lithium sulfimide in the lithium salt is 18-45%, the mass content of the unsaturated ester additive in the electrolyte is 0.05-5%, and the mass content of the unsaturated ester additive in the electrolyte is 0.05-5%. The unsaturated ester additive comprises one or more of vinylene carbonate, vinylethylene carbonate, allyl ethyl carbonate and a fluoro-carbonate additive; the amount of electrolyte in the battery cell is 2.8 g / Ah to 3.2 g / Ah. According to the invention, rapid charging and use reliability of the single battery can be considered.

The invention discloses an electrolyte, an electrochemical device comprising the electrolyte and a vehicle. The electrolyte comprises a solvent, a first additive and a second additive, the solvent comprises chain carboxylic ester, and the first additive comprises a sulfonate compound or / and a sulfate compound; the second additive comprises vinylene carbonate or / and fluoroethylene carbonate. According to the electrolyte disclosed by the invention, the chain carboxylic ester solvent, the first additive containing the sulfonate compound or / and the sulfate compound and the second additive containing the vinylene carbonate or / and the fluoroethylene carbonate are matched for use; the rapid charging capability and the high-temperature cycle performance of a lithium iron phosphate system battery with high safety performance can be improved, and the application of lithium iron phosphate in a power battery is further widened.

The invention relates to a lithium battery low-temperature electrolyte and a lithium ion battery, and belongs to the technical field of lithium batteries. Comprising the following steps: reducing the mass concentration (llt of conventional lithium salt by introducing a cosolvent; 13.5%), a synergistic positive / negative electrode film-forming additive, a low-impedance lithium salt additive and a functional additive. According to the invention, common low-melting-point and low-viscosity carboxylic ester is selected as a cosolvent, and the concentration of the lithium salt is reduced, so that the viscosity of the electrolyte at a low temperature is reduced, and the ionic conductivity is improved; a stable low-impedance positive / negative electrode interface film is constructed by cooperating with conventional positive / negative electrode film-forming additives such as vinylene carbonate and fluoroethylene carbonate, and the solvation structure of the electrolyte is regulated and controlled by introducing lithium salt additive anions, so that the desolvation process of lithium ions at low temperature is promoted, the low-temperature performance of the lithium battery is improved, and the service life of the lithium battery is prolonged. And the long cycle life of the electrolyte at normal temperature can also be ensured.

The invention provides a secondary battery, a battery device and a power utilization device, a negative pole piece in the secondary battery comprises a negative pole current collector and a negative pole film layer, the negative pole film layer is arranged on at least one side of the negative pole current collector, the negative pole film layer comprises a negative pole active material, the negative pole active material comprises graphite, and the powder compaction density of the negative pole active material under 20000N is 1.5-1.85 g / cm < 3 >; the electrolyte comprises an organic solvent and an organic additive, the organic solvent comprises a first solvent, the first solvent comprises cyclic carbonate, and the mass content of the first solvent is 17-34% based on the total mass of the electrolyte; the organic additives comprise a first additive and a second additive, the first additive comprises vinylene carbonate, the second additive comprises an ethylene carbonate derivative, based on the total mass of the electrolyte, the mass content of the first additive is 1.5%-8%, and the mass content of the second additive is 0.5%-4%.

The invention relates to a preparation technology of a gel polymer lithium ion battery cell electrolyte, and belongs to the field of battery preparation technologies, the preparation technology comprises the following steps: mixing methacrylate monomers and silane monomers according to a mass ratio of 3: 1-5: 1, adding 1-3% of an initiator, and carrying out prepolymerization at 60-80 DEG C for 1-3 h to prepare a prepolymer solution; mixing with a non-aqueous solvent containing lithium hexafluorophosphate according to a mass ratio of (1: 4)-(1: 6) to form a precursor mixed solution, and controlling the injection rate to be 1.5-2.5 g / Ah to a gap between a battery cell pole piece and a diaphragm; after standing for 2-4 hours at the vacuum degree of less than or equal to-0.08 MPa, curing for 3-6 hours at the temperature of 60-70 DEG C to form a gel polymer electrolyte; the wettability is improved through pole piece surface hydrophilic treatment, 1-5% of vinylene carbonate is added to optimize an SEI film, the prepolymerization temperature fluctuation is controlled to be smaller than or equal to + / -2 DEG C through microwave-assisted heating, the pressure of 0.2-0.5 MPa is applied after injection to promote uniform permeation, a polyvinylidene fluoride coating of 5-10 microns is coated after curing to enhance protection, and the interface performance is ensured through an alternating-current impedance test.

Secondary battery, including a positive electrode sheet comprising a positive electrode current collector and a positive electrode film layer, wherein the positive electrode film layer is arranged on at least one side of the positive electrode current collector and the positive electrode film layer comprises a positive electrode active material; a negative electrode sheet, wherein the negative electrode sheet comprises a negative electrode current collector and a negative electrode film layer, wherein the negative electrode film layer is arranged on at least one side of the negative electrode current collector and the negative electrode film layer comprises a negative electrode active material, wherein the negative electrode active material comprises graphite and the powder compaction density of the negative electrode active material at 20,000 N is 1.5 g / cm³ 3 up to 1.85 g / cm³ 3 is; and an electrolyte comprising an organic solvent and an organic additive, wherein the organic solvent comprises a first solvent, the first solvent comprising cyclic carbonate, and the mass fraction of the first solvent, based on the total mass of the electrolyte, is 17% to 34%; wherein the organic additive comprises a first and a second additive, the first additive comprising vinylene carbonate and the second additive comprising an ethylene carbonate derivative, and the mass fraction of the first additive is 1.5% to 8% and the mass fraction of the second additive is 0.5% to 4%, each based on the total mass of the electrolyte.

The invention discloses a lithium ion battery. The lithium ion battery comprises a positive pole piece and an electrolyte, the positive pole piece comprises a carbon-coated positive active material, the electrolyte comprises an additive, and the additive comprises vinylene carbonate; the lithium ion battery meets the relational expression that 0.15 < = C * theta / S < = 0.48, C is the mass percentage content of carbon coated by the carbon-coated positive electrode active material, and the unit is%; theta is the mass percentage content of vinylene carbonate, and the unit is%; s is the specific surface area of the carbon-coated positive electrode active material, and the unit is m < 2 > / g. When the lithium ion battery meets the relational expression, the cycle performance of the lithium ion battery can be effectively improved.

A negative pole piece in the secondary battery comprises a negative current collector and a negative film layer, the negative film layer is arranged on at least one side of the negative current collector, the negative film layer comprises a negative active material, the negative active material comprises first graphite, and the Dv50 particle size of the first graphite is 2.2-7.7 [mu] m; the electrolyte comprises an organic solvent and an organic additive, the organic solvent comprises a first solvent, the first solvent comprises cyclic carbonate, and the mass content of the first solvent is 25%-40% based on the total mass of the organic solvent; the organic additives comprise a first additive and a second additive, the first additive comprises vinylene carbonate, the second additive comprises an ethylene carbonate derivative, based on the total mass of the electrolyte, the mass percent of the first additive in the electrolyte is 2%-10%, and the mass percent of the second additive in the electrolyte is 0.3%-6%.

The invention provides a battery monomer, a battery device and a power utilization device. In the battery monomer, a positive electrode active material comprises lithium-containing phosphate with an olivine structure; the average particle size Dv50 of the negative electrode active material is 8-15 [mu] m, and the negative electrode active material comprises graphite; the electrolyte comprises a carbonic ester additive, the carbonic ester additive comprises fluoroethylene carbonate (FEC) and vinylene carbonate (VC), and based on the total mass of the electrolyte, the mass ratio of the carbonic ester additive is 0.5%-7%.

The invention discloses a battery monomer, a battery device and a power utilization device. A positive active material of a positive pole piece of the battery monomer comprises lithium-containing phosphate with an olivine structure, and the single-side coating weight of a positive film layer is 180mg / 1540.25 mm < 2 > to 380mg / 1540.25 mm < 2 >; the negative pole piece comprises a negative pole film layer, the negative pole film layer comprises a negative pole active material, the negative pole active material comprises a silicon-based material, and based on the mass of the negative pole active material, the mass content of the silicon element is 0.3%-10.0%; the electrolyte comprises a first additive, the first additive comprises at least one of vinylene carbonate and an ethylene carbonate derivative, the mass content of the first additive is 1%-12% based on the total mass of the electrolyte, and the compaction density of the positive electrode film layer is 2.50 g / cm < 3 >-2.80 g / cm < 3 > when the battery monomer is in a 100% state of charge.

The embodiment of the invention provides an electrolyte, a battery and electric equipment, the electrolyte comprises a lithium salt, an organic solvent and a polymer matrix, and monomers of the polymer matrix comprise vinylene carbonate and isocyanate ethyl acrylate. In the electrolyte provided by the embodiment of the invention, the monomers of the polymer matrix comprise vinylene carbonate and isocyanate ethyl acrylate, and the low HOMO energy level of isocyanate ethyl acrylate can weaken the electron loss ability of the polymer matrix and improve the oxidation stability of the electrolyte, so that the relatively poor electrochemical stability is improved; and a copolymerization structure of vinylene carbonate and isocyanate ethyl acrylate reduces the crystallinity of a polymer matrix and provides a smoother path for Li < + > transmission, so that the ionic conductivity of the electrolyte is improved. Therefore, the electrolyte provided by the invention can effectively improve the problems of low room-temperature ionic conductivity and relatively poor electrochemical stability of the existing gel electrolyte, and has a good application prospect.

The invention relates to a battery monomer, a battery device and a power utilization device. The battery monomer comprises a positive pole piece and a negative pole piece, the positive pole piece comprises lithium-containing phosphate; the negative pole piece comprises graphite particles; the electrolyte comprises a carboxylic ester solvent, a linear carbonic ester solvent and an additive, the mass content of the carboxylic ester solvent is 10%-30%, and the mass content of the linear carbonic ester solvent is 10%-50%; the mass content of the additive is 3%-9%, the additive comprises 1, 3-propane sultone with the mass content larger than or equal to 0, an ethylene carbonate derivative with the mass content larger than or equal to 0 and vinylene carbonate with the mass content larger than 0, and the ethylene carbonate derivative comprises a compound shown in the formula A; q1, Q2, Q3 and Q4 each independently comprise any one of a hydrogen atom, a halogen atom, a C1 to C5 alkyl group or a C1 to C5 halogenated alkyl group, and Q1, Q2, Q3 and Q4 are not hydrogen atoms at the same time. # imgabs0 # formula A is shown in the specification.

The invention relates to a continuous production process and device of vinylene carbonate, chloroethylene carbonate, tertiary amine and a solvent are continuously fed in a reactor for dechlorination reaction, and temperature is controlled by a tubular heat exchanger; the reaction liquid continuously overflows from a side overflow port to enter a middle receiving tank, a vinylene carbonate crude product is obtained after desolvation, the vinylene carbonate crude product enters a melt crystallizer for melt crystallization after being purified by a low-component removal tower, a high-component removal tower and a rectifying tower, and a vinylene carbonate product with the purity of 99.99% or above is obtained; a reaction by-product tertiary amine hydrochloride settles to the lower part of the reactor, is discharged from the bottom of the reactor after being subjected to countercurrent washing by inputting a solvent through a salt leaching cavity, enters a neutralization kettle, is neutralized by liquid caustic soda and then is subjected to liquid separation, an organic phase enters a recovery system to be dehydrated, and then sequentially passes through a solvent recovery tower to recover the solvent and a tertiary amine recovery tower to recover tertiary amine; and the solvent and the tertiary amine can be recycled. The continuous production of the vinylene carbonate is realized, the consumption of raw materials is reduced, and the yield and the production efficiency are improved.

The invention relates to the technical field of battery diaphragm preparation, in particular to a lithium ion battery diaphragm and a preparation method thereof.The lithium ion battery diaphragm comprises a diaphragm base material and modified slurry coating the surface of the diaphragm base material; a preparation method of the modified slurry comprises the following steps: adding the modified conductive polymer, the modified graphene and the vinylidene fluoride polymer into N-methyl pyrrolidone, uniformly stirring, adding vinylene carbonate, and fully stirring to obtain the modified slurry. The preparation method of the lithium ion battery diaphragm comprises the following steps: coating the modified slurry on the surface of the diaphragm base material, and flattening and curing to obtain the lithium ion battery diaphragm. The lithium ion battery diaphragm prepared in the invention has good thermal stability, can keep a stable structure in a normal working temperature range of a battery, has excellent air permeability, good diaphragm electrolyte wettability, reduced resistance, improved ionic conductivity, good capacity retention rate after long-term use, and is more durable.

The invention provides an electrolyte and a lithium ion battery. The electrolyte comprises a solvent, additives and lithium salt, the lithium salt comprises lithium bis (fluorosulfonyl) imide, the additives comprise a first additive and a second additive, the first additive is selected from a compound shown in the formula I, and the second additive is selected from vinylene carbonate. The first additive and the second additive have a synergistic effect, so that the high-temperature storage performance and the thermal stability of the lithium ion battery are improved. # imgabs0 #

The invention discloses a lithium manganese iron phosphate secondary battery and device, and relates to the technical field of lithium manganese iron phosphate batteries. The lithium manganese iron phosphate secondary battery comprises an electrolyte and a positive pole piece, wherein the positive pole piece comprises a lithium manganese iron phosphate positive pole material; the electrolyte comprises an additive and an organic solvent, the additive comprises vinylene carbonate, and the mass of the vinylene carbonate accounts for 0.8%-1.7% of the total mass of the electrolyte; the organic solvent comprises ethylene carbonate, and the mass of the ethylene carbonate is 10-19% of the total mass of the electrolyte; the mass content of the fluorine element in the electrolyte is 7.5%-12.75%; the mass content of fluoroethylene carbonate in the electrolyte is less than 10 ppm, and the mass content of boron is less than 10 ppm. According to the invention, the contents of vinylene carbonate, ethylene carbonate and total fluorine element in the electrolyte are accurately controlled, and meanwhile, the contents of fluoroethylene carbonate and boron element are strictly limited to be less than a preset threshold value, so that the dissolution of manganese ions is effectively inhibited, and the cycle life of the battery at high voltage and high temperature is remarkably prolonged.

A non-aqueous electrolyte and a quick-charging secondary battery. The non-aqueous electrolyte comprises a primary injection electrolyte and a secondary injection electrolyte. The primary injection electrolyte comprises a mixed lithium salt, a carboxylic acid ester solvent, and a primary additive; the primary additive comprises vinylene carbonate and fluoroethylene carbonate; and on the basis of the mass of the primary injection electrolyte, the mass percentage content of the vinylene carbonate is A%, and the mass percentage content of the fluoroethylene carbonate is B%, wherein the value of A+B ranges from 1 to 6. The secondary injection electrolyte comprises a secondary additive; the secondary additive comprises vinylene carbonate; and on the basis of the mass of the secondary injection electrolyte, the mass percentage content of the vinylene carbonate is C%, wherein the value of (A+B) / C ranges from 0.06 to 0.48. The non-aqueous electrolyte is applicable to quick-charging and wide-temperature secondary battery systems.

The invention provides a lithium secondary battery and a power utilization device. The lithium secondary battery comprises a positive electrode piece, a negative electrode piece and electrolyte, the negative electrode piece comprises a negative electrode current collector and a negative electrode film layer arranged on at least one side of the negative electrode current collector, the negative electrode film layer comprises a negative electrode active material, and the specific surface area a of the negative electrode active material is greater than or equal to 2m < 2 > / g and less than or equal to 5m < 2 > / g; the electrolyte comprises propylene carbonate, a first additive and a compound with a formula I, R is selected from halogen, n is an integer selected from 1-6, and the first additive comprises at least one of ethylene sulfate, vinylene carbonate, fluoroethylene carbonate, 1, 3-propane sultone, 1, 3-propene sultone, tetravinyl silane or methylene methanedisulfonate. The lithium secondary battery provided by the invention has relatively good low-temperature quick charge performance and also has cycle performance.

The present application comprises an electrolyte and a sodium-ion battery. The electrolyte comprises a sodium salt main salt, a sodium salt auxiliary salt, an organic solvent, and an additive. The sodium salt auxiliary salt comprises sodium difluorophosphate and the additive comprises vinylene carbonate, the mass percentage of the sodium salt auxiliary salt in the electrolyte being 0.01%-1%, and the mass percentage of the vinylene carbonate in the electrolyte being 0.5%-3%. The electrolyte provided in the present application enables batteries to exhibit excellent low-temperature cycling performance, rate performance, and initial coulombic efficiency.

The invention discloses a preparation method of vinylene carbonate, which comprises the following step: reacting chloroethylene carbonate under the action of a catalyst to generate vinylene carbonate, wherein the catalyst comprises a modified titanium silicalite molecular sieve and a metal salt loaded on the modified titanium silicalite molecular sieve, the modified titanium silicalite molecular sieve is obtained by calcining the titanium silicalite molecular sieve and then etching the titanium silicalite molecular sieve with tetraalkyl ammonium hydroxide, and metal elements in the metal salt have d orbital electrons; practice shows that the method can directly remove hydrogen chloride from chloroethylene carbonate to generate vinylene carbonate, the reaction temperature is unexpectedly reduced and can be reduced to 200 DEG C or even below 180 DEG C, the energy consumption and the safety performance in the production process are greatly reduced, a solvent is not needed in the reaction process, and the method is suitable for industrial production. And no solid waste is generated.

The invention relates to the field of batteries, and provides an electrolyte additive, an electrolyte and a battery. The electrolyte additive comprises a siloxane compound, vinylene carbonate and fluoroethylene carbonate, the siloxane compound is at least one of compounds as shown in a formula 1, in the formula 1, m represents any integer from 1 to 12, R1, R2 and R3 are the same or different and are independently C1-C8 alkyl groups, C1-C8 alkoxy groups and the like, and one or two of R1, R2 and R3 are C1-C8 alkoxy groups. The electrolyte additive can improve the electrochemical performance of the battery. # imgabs0 #

The invention relates to the technical field of lithium battery electrolyte, in particular to a composite enhanced solid electrolyte membrane and a preparation method thereof. The polymer solid electrolyte is a polycarbonate-based solid electrolyte such as a poly (ethylene carbonate)-based solid electrolyte PVC, a poly (vinylene carbonate)-based solid electrolyte PEC, a poly (propylene carbonate)-based solid electrolyte PPC, a poly (propylene carbonate)-based solid electrolyte PTMC and a polyoxyethylene-based solid electrolyte. The electrolyte is one or more of polysiloxane-based polymer electrolyte and single-lithium-ion conductive polymer electrolyte materials. The composite enhanced solid electrolyte membrane is disclosed. The preparation method comprises the following steps: preparing the three-dimensional nanofiber skeleton through electrostatic spinning, loading the two surfaces of mixed slurry of the polymer electrolyte and the lithium salt on the base membrane in an inert atmosphere, and carrying out vacuum curing molding. The composite membrane has high safety and a wide electrochemical window, the process of the composite membrane is compatible with an existing lithium battery production line, the raw material cost is controllable, and the composite membrane has large-scale commercial application potential.

The invention provides a method for evaluating the cycle risk of a lithium ion battery, and relates to the technical field of batteries. According to the research of the inventor, the content of vinylene carbonate in the electrolyte is strongly related to the cycle performance of the lithium ion battery, and when the content of vinylene carbonate in the electrolyte is 0, a diving phenomenon is extremely easy to occur in continuous cycle of a battery cell, so that the invention provides the method for evaluating the cycle risk of the lithium ion battery. According to the method, the cycle number of the lithium ion battery and the amount of residual vinylene carbonate in electrolyte are fitted, the cycle number which can be supported by the battery is predicted according to a fitting curve, and if the cycle number of the battery exceeds the cycle number which can be supported by the battery, it is predicted that the battery has the diving risk. The method is good in accuracy, and improves the efficiency of evaluating the battery life risk.