117results about How to "Guaranteed cycle stability" patented technology

The invention relates to a production method of a boron nitride coated diaphragm of a lithium-sulfur battery. The diaphragm is produced from a commercial polypropylene diaphragm, two sides of the diaphragm are uniformly covered with hexagonal boron nitride, and the characteristics of hexagonal boron nitride 'white graphite' are used, so lithium ions are allowed to pass, shuttle of polysulfide anions is obstructed, a reaction of a lithium negative electrode with the polysulfide anions is inhibited, formation of lithium dendrites, lithium sulfide precipitate and fixed lithium is prevented, the capacity, the coulombic efficiency and the cycle stability of the lithium-sulfur battery are improved, the growth of the negative electrode metal dendrite in the cycle process is effectively inhibited, and the safety of the battery is improved. The method has the advantages of simple process route and clear purpose, and the produced diaphragm has multiple functions, and can greatly overcome disadvantages of present technologies.

The invention relates to a preparation method of a foam metal matrix oxide electrode used in the lithium-ion battery cathode, relating to a metal electrode used in the lithium-ion battery cathode and a preparation method thereof. The invention aims to solve the problems of the existing lithium-ion battery anode material that the specific capacity is low, the cycle performance is poor and the preparation method is complicated. The foam metal matrix oxide electrode uses one or two of foam metals comprising Cu, Ni and Fe as the matrix. The preparation method of the foam metal matrix oxide electrode comprises the following steps: 1) cleaning with acid solution; 2) soaking with alkaline solution; and 3) generating one or two of the corresponding transition metal oxides, namely CuO, Cu2O, NiO, Ni2O, Fe2O3 and Fe3O4 on the foam metal in situ through low-temperature roasting and other steps to obtain the foam metal / transition metal oxide composite electrode. The preparation method is simple, the electrode has high specific capacity, long cycle life and excellent rate performance; and the electrode is suitable for the lithium-ion battery system of an electric vehicle.

The invention relates to a nitrogen-doped carbon nanotube adopting a hierarchical structure and a preparation method. The material is doped with nitrogen and adopts the obvious hierarchical structure, and the carbon nanotube comprises tinier nitrogen-doped carbon particles. The preparation method comprises steps as follows: aniline is uniformly dispersed in an acid solution through stirring, an aniline suspension is obtained and subjected to ice bath treatment for 20-60 min, and stirring is kept in the ice bath process; an oxidizing agent is dissolved in deionized water through stirring and subjected to ice bath treatment for 5-30 min; stirring is stopped, an oxidizing agent solution is quickly poured into an aniline suspension mixed solution and subjected to ice bath treatment for 8-28 h, centrifugal washing is performed by the aid of deionized water and ethanol until a supernatant is clarified, and a sample is dried in an oven; the dried sample is ground, subjected to heat treatment in air and naturally cooled; a treated composite is calcined at the high temperature in an inert atmosphere and naturally cooled. The nitrogen-doped carbon nanotube has the advantages of high capacity, good rate capability and good circulating performance and can be used as an anode material for a lithium ion battery.

The invention belongs to the field of functional fiber, and particularly relates to thermochromic fiber and a preparation method and application thereof. The thermochromic fiber is of a core-claddingstructure, a core layer of the core-cladding structure is a thermochromic layer, and the cladding layer is a protection layer and positioned outside the core layer. The thermochromic layer is preparedby adopting a thermal softening drawing method. The preparation method includes: obtaining a prefabricated rod of the thermochromic layer, and performing thermal softening drawing on the prefabricated rod to obtain the thermochromic layer fiber, wherein thermal softening drawing is a thermal softening drawing method adopted in an optical fiber preparation process. Compared with existing thermochromic fiber preparation methods, the drawing process is wide in thermochromic material and polymer base material selection range and diverse in structure design; fiber different in section structure can be designed, distribution of different thermochromic materials in the fiber can be controlled accurately, and the preparation method is high in production efficiency and suitable for large-scale production.

The invention discloses a safe high-voltage high-energy-density lithium ion battery and a preparation method thereof. The safe high-voltage high-energy-density lithium ion battery comprises a positiveplate, a negative plate, an electrolyte and a diaphragm; the positive plate comprises an aluminum foil current collector and a positive active material coating, the positive active material is a single crystal nickel cobalt lithium manganate mixture coated with titanium oxide according to a certain ratio, the negative plate comprises a copper foil current collector, a negative active material coating and a ceramic coating, the negative active material coating is coated with the ceramic coating, wherein the positive active material is one or two of single crystal NCM523 and single crystal NCM622 after being subjected to titanium oxide coating treatment, the negative active material is a high-capacity graphite material, the electrolyte is a high-voltage electrolyte, and the voltage range is4.0-6.0V. According to the lithium ion battery prepared by utilizing the material, the battery energy density is improved, and good safety performance is achieved while the battery has excellent cycling performance.

The invention discloses a lithium-supplemented electrode of a negative electrode of a lithium ion battery and a preparation method thereof, wherein the lithium-supplemented electrode with the negativeelectrode material or the electrode sheet being pre-lithium treated is coated with an organic thin film layer on the surface of the pre-lithium electrode, and the organic thin film layer is composedof an electrolyte lithium salt dissolved in an organic solvent. The organic coating liquid is prepared by coating electrolyte lithium salt on the surface of the pre-lithium electrode, forming an organic thin film layer on the surface of the pre-lithium electrode, preventing the pre-lithium layer of the pre-lithium electrode from being oxidized, improving the first efficiency, cycle stability and processing performance of the lithium ion battery, and reducing the influence of the production environment on the lithium supplement electrode.

The invention provides an electrolyte for a high-voltage lithium ion battery, and belongs to the field of a lithium ion battery. The electrolyte comprises a non-aqueous organic solvent, a lithium saltand an additive, wherein the non-aqueous organic solvent is an ester solvent, the mass percent of the non-aqueous organic solvent accounts for 95% or above, the lithium salt is LiPF6, the concentration of the lithium salt is (1.0-1.5)mol / L, the additive is a mixture of a dinitrile compound and a boron-containing compound, and the mass percent of the additive accounts for 1-5%. The electrolyte employing the mixture of the dinitrile compound and borate as an electrolyte additive is applicable to a high-voltage positive electrode material LiNi<0.5>Mn<1.5>O<4> system, it is found that the interface impedance of the lithium ion battery positive electrode material can be improved by such the electrolyte, and moreover, the cycle stability of the lithium ion battery under a normal temperature isimproved.

The invention relates to a method for preparing a modified graphite negative electrode material of a lithium ion power battery. The method particularly comprises the following steps: adding asphalt and resin into a kneading kettle with heating and stirring devices, heating until the asphalt and the resin are melted into liquid, continuously stirring, stopping heating after mixing uniformly and cooling to obtain a composite coating material block; performing coarse crushing on the composite coating material block and performing ultrafine crushing by using an airflow crushing machine or a cryogenic crushing machine to obtain composite coating material ultrafine powder; completely mixing the composite coating material ultrafine powder and graphite to obtain uniform powder; and performing heating, heat preservation and natural cooling on the uniform powder under the protection of inert gas, and sieving after cooling to obtain the modified graphite negative electrode material of the lithium ion power battery. The most outstanding innovation points are that the coating material precursor is subjected to compound treatment and coated by the graphite; the mixing uniformity of various coating material precursors is guaranteed, any solvents are not required, and environmental friendliness is realized; in addition, the process is simple, low in cost and easy in industrialized production.

The invention discloses a preparation method of ZIF complex based novel lithium ion battery cathode materials.The preparation method has the advantages that a novel zeolitic imidazole organic framework compound is synthesized to prepare nitrogen-doped porous carbon materials which are applied to the lithium ion battery cathode materials, so that first specific discharge capacity reaches 1211 mAh / g, charge-discharge current density reaches 100 mA / g, and specific capacity is almost about 620 mAh / g (a theoretical value of commercial graphite cathode specific capacity reaching 372 mAh / g); even if the lithium ion battery cathode materials cycle for 100 times, good cycle performance can be demonstrated, and when current density reaches 1000 mAh / g, specific capacity can also reach 410 mAh / g, so that excellent rate performance can be demonstrated.

The invention discloses a lithium ion battery with high-rate charge-discharge performance. According to the lithium ion battery, high-rate lithium cobalt oxide is taken as an anode, high-rate intermediate carbon microspheres are taken as a cathode, and graphene is taken as a conductive additive. Cathode and anode material systems with the high-rate properties are adopted, the surface density and the compaction density of pole pieces of the anode and the cathode are controlled, high conductivity of the pole pieces is guaranteed, and the high-current charge-discharge performance of the battery is improved. The graphene with the high conductivity is taken as the conductive additive, the defect that the proportion of active materials for the anode and the cathode is reduced due to heavy addition of a conventional conductive additive is overcome, and the volume energy density of the battery is increased. An electrolyte containing a PC (polycarbonate) solvent with a high solidifying point and high electric conductivity is adopted, so that the heat dissipation problem of the battery under the high-current charge and discharge condition is effectively solved, and the cyclic stability of the battery is further guaranteed. The lithium ion battery is simple in process, and the performance of the prepared lithium battery is excellent.

The invention provides a cross-linked modified polyimide single-ion polymer. The cross-linked modified polyimide single-ion polymer has a chemical structure shown as formula (I). Polyimide and a 4-styrene sulfonyl(benzenesulfonyl)imide lithium salt are combined together by utilizing an enol click chemical reaction through ultraviolet curing, anions are better fixed on a polymer, and the transmission distance of lithium ions is shortened, so that the lithium ion transference number and the ionic conductivity of the polymer electrolyte prepared from the material are improved; meanwhile, pentaerythritol tetra(3-mercaptopropionate) (PETMP) can be connected with a plurality of lithium salt molecules, so that more lithium sources are provided; the transference number of electrolyte Li<+> can beincreased due to low lithium ion delocalization energy of lithium disulfimide of the 1, 4-styrene sulfonyl(benzenesulfonyl)imide lithium salt; a plasticizer with good thermal stability is also added to improve the ionic conductivity; and then, the thermal stability and ionic conductivity of the polymer gel electrolyte and the cycling stability of the battery are ensured, and the use safety of thelithium ion battery is ensured.

The invention relates to a preparation method of multi-element cathode material coated by graphene. The active material of the multi-element cathode material comprises an inner layer and an outer layer, wherein the active material has the following chemical formula (1-a) LiNi1-xCoxO2.aLiMn0.3Al0.7O2, wherein a is equal to 0.3-0.35, and the x is equal to 0.25-0.45. The method comprises the following steps: (1) preparing the active material; (2) preparing graphene derivate materials; (3) coating the active material by the graphene derivate materials. The multi-element cathode material prepared by the method disclosed by the invention adopts a two-layer structures with various component matching ratios, the proportion of the nickel in the inner layer is the highest, so that the high capacity of the material is ensured; the outer layer has higher cobalt content, so that the cycling stability of the material is ensured; finally, another layer of graphene derivate material is adopted for coating the active material, so that the activity and the capacity of the material are further improved. Therefore, when the cathode materials are applied to lithium batteries, the specific capacity is higher, and the stability is good.

The invention provides a preparation method for a tin-carbon composite negative material. An outer layer of the tin-carbon composite negative material is a composite cladding layer jointly formed by asphalt, resin and tin powder, and an inner layer is the tin-carbon composite negative material which is composed of graphite and has a core-shell structure. In the tin-carbon composite material prepared according to the method, high specific capacity characteristic of tin is maintained, meanwhile, a modification effect on the graphite is played, the overall cyclic stability of the material is improved, the energy density of the negative material of a lithium ion battery is improved, thus, the negative material has higher specific capacity than the carbon negative material commonly used in the lithium ion battery in the current market, and the increasing energy density requirement of various portable electric devices on the battery is met.

The invention relates to a preparation method for a micron-sized composite LiFePO4 / C cathode material for a lithium ion battery. The method comprises the following steps of uniformly mixing an iron source, a phosphorus source and an organic carbon source, and pre-sintering the mixture to obtain a composite iron phosphate / carbon precursor; uniformly mixing the obtained composite precursor, a lithium source and an inorganic carbon source, performing compression molding, preserving heat for a certain time under 700 to 800 DEG C and certain inert gas pressure in a sintering furnace, and performing crushing to obtain the composite LiFePO4 / C cathode material after temperature reduction. The invention also relates to the micron-sized composite LiFePO4 / C cathode material obtained by the method and with a nano carbon conducting network. The material has the characteristics of high purity, high tap density, high consistency, high processability and high rate discharge performance.

The invention provides a method for preparing ultra-high purity difluoromono-chloroethane, which comprises the following steps: mixing raw materials at a mole ratio of 1.15:1 and feeding the mixture into a photochlorination reactor for reaction, feeding the reactant into a two-stage water absorption HCL tower and a two-stage alkali liquor absorption chlorine gas tower to remove HCL and chlorine; feeding the obtained product into a dry buffer tank; compressing the gas from the dry buffer tank with a single-stage oil-free compressor and feeding the compressed gas into a degassing tower and a rectifying tower for degassing and rectifying to obtain difluoromono-chloroethane with moisture; and then removing the moisture with a molecular sieve drier to obtain a pure difluoromono-chloroethane product. According to the method, the production flow of the difluoromono-chloroethane is shortened, the reaction conversion rate is high, the by-products are few, the rectifying efficiency is high, the raw materials and the energy consumption are reduced, the purity of the product is high and the production of the whole set of device is safe and economic.

The invention discloses a lithium-ion battery with high energy density. The lithium-ion battery comprises a positive electrode piece, a diaphragm, a negative electrode piece, a shell body and electrolyte, wherein the diaphragm is arranged between the positive electrode piece and the negative electrode piece; the positive electrode piece, the diaphragm and the negative electrode piece are arrangedin the shell body after being wound; the shell body is fully filled with the electrolyte; the positive electrode piece comprises a positive electrode current collector and a positive electrode activelayer which is covered on the surface of the positive electrode current collector; the negative electrode piece adopts a copper foil current collector; the electrolyte is prepared from lithium salt, asolvent and an additive; the lithium salt comprises one of LiFSI and LiTFSI; the invention further discloses a preparation method of the lithium-ion battery. The lithium-ion battery disclosed by theinvention has the advantages that the copper foil current collector is used as the negative electrode piece, the high-performance lithium salt is matched and the mass of the negative electrode piece is alleviated, so that the mass of the lithium battery is reduced and the energy density is improved; the cycling life and stability of the lithium battery are ensured and a procedure for preparing thenegative electrode piece is simplified; raw materials are saved and the production cost is reduced.

The invention relates to a preparation method of a foamed nickel self-supporting nickel nanotube super capacitor electrode material, which comprises the following steps: pre-treating foamed nickel; growing zinc oxide nanorods on the surface of the pretreated foamed nickel by adopting a hydrothermal method or an electro-deposition method; electrically depositing an elemental nickel layer on the surface of the zinc oxide nanorods to obtain a zinc oxide@nickel core-shell structure; and finally, calcining and etching the zinc oxide@nickel core-shell structure. The preparation process is convenient, simple, green, environmentally friendly and low in cost. The problem that materials contain too many impurities and the operation is complex in a traditional process is solved. A super capacitor energy storage material containing novel nickel nanotubes is constructed from another direction. In addition, the nickel nanotubes are grown on the surface of the foamed nickel to serve as a self-supporting electrode material with good conductivity and a stable structure, the hollow tubular structure can provide a larger specific surface area, and the charge-discharge cycling stability of a whole capacitor is ensured while the conductivity is improved.

The invention relates to the technical field of battery negative electrode materials, and provides a silica negative electrode material and a lithium ion battery. The silica negative electrode material has a core-shell structure and comprises an inner core, a middle layer coating the surface of the inner core and an outer shell layer coating the surface of the middle layer; the material of the inner core comprises amorphous silicon oxide and silicon microcrystals, and the sizes of the silicon microcrystals are increased in a gradient manner along the direction from the center of the inner core to the surface layer of the inner core; the middle layer is made of silicon carbide; and the outer shell layer comprises a carbon layer. The negative electrode core material with the characteristics can guide huge volume expansion stress generated in a lithium embedding process to be released outwards through silicon microcrystals which are distributed in an amorphous silicon oxide main body material and have gradually changed sizes, so that volume expansion of the silicon-based negative electrode material is inhibited, and irreversible capacity increase caused by volume expansion is reduced; therefore, the cycle life of the silicon-based negative electrode material is effectively prolonged.

The invention discloses a preparation method for lithium battery anode slurry doped with tin powder. By adding nanometer tin powder in the conventional anode slurry preparation process, the capacity playing performance of the material is improved, and the requirements of a lithium ion battery for the high-energy density can be met; in addition, through the steps of thickening agent solution preparing, powder body dispersing, high-viscosity stirring, low-viscosity stirring, viscosity testing, vacuum defoaming and the like, all the components, especially the nanometer tin powder, are fully dispersed in an anode system, agglomeration of the nanometer tin powder is avoided, and the cycling stability is guaranteed. The preparation method has the advantages of being short in preparation time, little in equipment wear, low in production energy consumption, good in dispersion effect and the like. The lithium battery prepared by adopting the anode slurry is low in internal resistance, high in volume energy density and good in cycling performance.

The invention provides a device and a method for preparing ultra-high purity difluoromono-chloroethane. The device comprises a heat exchangeable photochlorination reactor, an HCL-removing tower, a chlorine-removing tower, a dry buffer tank, a single-stage oil-free compressor, a degassing tower, a rectifying tower, a molecular sieve drier and a product tank. The method comprises the following steps: mixing raw materials and feeding the mixture into a photochlorination reactor for reaction, feeding the reactant into a two-stage water absorption HCL tower and a two-stage alkali liquor absorption chlorine gas tower to remove HCL and chlorine; feeding the obtained product into a dry buffer tank; compressing the gas from the dry buffer tank with a single-stage oil-free compressor and feeding the compressed gas into a degassing tower and a rectifying tower for degassing and rectifying to obtain difluoromono-chloroethane with moisture; and then removing the moisture with a molecular sieve drier to obtain a pure difluoromono-chloroethane product. According to the device and the method, the production flow of the difluoromono-chloroethane is shortened, the reaction conversion rate is high, the by-products are few, the rectifying efficiency is high, the raw materials and the energy consumption are reduced, the purity of the product is high and the production of the whole set of device is safe and economic.

The invention discloses a doped modified lithium ion sieve. The doped modified lithium ion sieve adopts a molecular formula as follows: HMxMn2-xO4, wherein M is Co or Ni and x is greater than or equalto 0.020 and smaller than or equal to 0.095; the crystal form of the doped modified lithium ion sieve is a single pure-phase spinel crystal form; the lithium ion sieve is spherical and has the average particle diameter of 2-5 microns. The invention further correspondingly provides a preparation method and the application of the doped modified lithium ion sieve. Through doping modification of nickel or cobalt, the cell structure of the doped modified lithium ion sieve is more stable, so that the problem of easy dissolution of the conventional HMn2O4 lithium ion sieve is solved, and the doped modified lithium ion sieve can be repeatedly recycled for many times; in addition, the doped modified lithium ion sieve has excellent morphology, small average particle size and a relatively large specific surface area, and the specific morphology thereof benefits sufficient contact of lithium-containing liquid, facilitates intercalation and extraction of lithium ions and benefits maintenance of the cycle stability of a material.

The invention relates to a carbon-azine composite water-based negative electrode material and application thereof. The carbon-azine composite water-based negative electrode material utilizes the conductivity, porosity and adsorbability of a nano carbon material and the reaction capability of polycyclic aromatic hydrocarbon-like compounds of the carbon material to carry out functionalized graftingto form a cross-linked network structure, so as to improve the liquid absorbency and ionic conductivity of the carbon material, and compound the heterocyclic azine compound onto carbon granules to form a carbon-azine composite material. The carbon-azine composite material is used as a water-based negative electrode, a sodium manganate or nickel hydroxide electrode is used as a positive electrode,and an electrolyte is a liquid or gel-state material taking sodium salt or sodium hydroxide as a solute and water as a solvent; and the positive electrode and the negative electrode are separated by adiaphragm to form a battery. The negative electrode material has high utilization rate and capacity, is applied to an aqueous rechargeable battery, and has high specific discharge capacity and good cycle performance; and a water-based rechargeable battery composed of the carbon-azine composite water-based negative electrode material and the sodium manganate or nickel hydroxide positive electrodehas the advantages of relatively high specific energy, safety, low cost, environmental protection and long cycle life.

The invention discloses a preparation method of an ultrathin carbon-coated tin dioxide nano composite material, which comprises the following steps: 1. dissolving a carbon source, a tin source and naphthalene in a certain ratio in deionized water, adding a proper amount of hydrochloric acid to regulate the pH value, and carrying out hydrothermal reaction on the mixed solution; and 2, calcining a product obtained by the hydrothermal reaction in a tubular furnace in an argon atmosphere to obtain the ultrathin carbon-coated tin dioxide nano composite material. The ultrathin carbon-coated stannicoxide nano composite material prepared by the invention has good cycling stability, excellent rate capability and high specific discharge capacity as a lithium ion negative electrode material.

The invention discloses a current collector. The surface of the current collector has a solid electrolyte interface phase. The solid electrolyte interface phase is prepared by adopting an electrochemical control method after introducing a sacrificing lithium thin layer, wherein the sacrificing lithium thin layer is formed by metal lithium with a certain thickness by the adoption of an electro-deposition or non-electro-deposition method.

The invention provides a nitrogen-doped carbon-coated manganese sulfide composite negative electrode material and a preparation method and application thereof, and belongs to the technical field of negative electrode materials, and the preparation method comprises the following steps: ball-milling micron manganese sulfide, mixing the micron manganese sulfide with a nitrogen-containing polymer and a solvent, drying, and roasting to obtain the nitrogen-doped carbon-coated manganese sulfide composite negative electrode material. Nanometer manganese sulfide can be obtained by adopting micron manganese sulfide through one-step ball milling, then the nanometer manganese sulfide and a nitrogen-containing polymer solution are mixed, dried and then subjected to high-temperature roasting, the nitrogen-containing polymer is pyrolyzed to form a nitrogen-doped carbon matrix material in the high-temperature roasting process, the ion diffusion path is shortened through nanometer manganese sulfide particles, the nitrogen-doped carbon substrate material improves the electronic conductivity and the structural stability of the negative electrode material, and the negative electrode material is of a micro-nano structure, so that the specific surface area of the material is reduced, and the first efficiency and the tap density are improved, thereby ensuring the electrochemical performance of the material, especially the cycling stability under high magnification; the preparation process is simple, and no other harmful by-products are generated.

The invention provides an iron-manganese-based positive electrode material, and a preparation method and an application thereof. The preparation method comprises the steps that S1, an inorganic compound of lithium and a FexMny (OH) 2 precursor are subjected to oxidation sintering, an intermediate product is obtained, x is larger than 0 and smaller than 1.0, y is larger than 0 and smaller than 1.0, x + y = 1, and the ratio of the molar weight of Li in the inorganic compound of lithium to the total molar weight of Fe and Mn in the FexMny (OH) 2 precursor ranges from 0.1: 1 to 0.5: 1; and S2, second sintering is performed on the intermediate product in a nitrogen or first inert gas atmosphere condition to obtain the iron-manganese-based positive electrode material. The iron-manganese-based positive electrode material obtained by the preparation method disclosed by the invention is relatively low in lithium element content and relatively stable in structure so that the original structure of the iron-manganese-based positive electrode material is not influenced in the embedding and separating processes of lithium ions between a positive electrode and an electrolyte, and the cycling stability of the lithium ion battery is further ensured.

The invention discloses a succinonitrile-based electrolyte coupled with an organic lithium salt and fluoroethylene carbonate, and relates to the technical field of lithium-ion batteries. The specificscheme is as follows: the succinonitrile-based electrolyte coupled with an organic lithium salt and fluoroethylene carbonate comprises succinonitrile, an organic lithium salt and fluoroethylene carbonate, wherein the molar ratio of the succinonitrile to the organic lithium salt is 100: 1-1:1, the organic lithium salt is a combination of a sulfonyl imide lithium salt and lithium oxalyldifluoroborate, the molar ratio of the sulfonyl imide lithium salt to the lithium oxalyldifluoroborate is 100: 1-1: 1, and the fluoroethylene carbonate accounts for 5-50% of the total volume of the succinonitrile-based electrolyte. The invention further discloses a preparation method of the succinonitrile-based electrolyte and application of the succinonitrile-based electrolyte to a lithium metal battery, theelectrolyte can form an organic-inorganic composite SEI film on the surface of metal lithium, side reaction of succinonitrile and metal lithium is avoided, and the interface stability and electrochemical performance of the battery are remarkably improved.

The invention discloses a preparation method of a high-performance lithium ion battery polyacrylonitrile carbon fiber negative electrode material. The preparation method comprises the following steps of: dissolving polyacrylonitrile in a DMF solvent, and fully stirring to obtain a spinning solution; spinning the spinning solution to obtain stable nanofiber filaments, and continuously spinning to obtain polyacrylonitrile protofilaments; placing the polyacrylonitrile protofilaments in a porcelain boat, performing heating and pre-oxidizingin a tubular furnace under an oxygen atmosphere, and cooling to room temperature to obtain pre-oxidized fibers; carbonizing the pre-oxidized fibers in the tubular furnace in a nitrogen atmosphere, and naturally cooling the carbonized pre-oxidized fibers to room temperature to obtain polyacrylonitrile carbon fibers; fully grinding the carbonized polyacrylonitrile carbon fibers in an agate mortar, and drying an obtained substance to obtain the superfine electrostatically-spun polyacrylonitrile carbon fiber material. The lithium ion battery polyacrylonitrile carbon fiber negative electrode material has the advantages of high performance, high capacity, high cycling stability, high charging specific capacity and long cycle life.

The invention discloses a method of preparing TiO2-modified P / C composite anode material and belongs to the field of electrochemical and new-energy materials. In the method, red phosphorus, anthraciteand nano-TiO2 are uniformly blended and then the mixture is mechanically ball-milled in a high-energy ball mill tank filled with inert gas, thus obtaining the TiO2-modified P / C composite anode material. Due to low cost of the anthracite, the method is suitable for low-cost large-scale production. The composite material is used as an anode of a sodium-ion battery and shows high reversible specificcapacity and great cycle stability. The method, as the anode of the sodium-ion battery, has certain application prospect.

The invention provides a polyimide single-ion polymer, a preparation method thereof and a solid polymer electrolyte membrane. The chemical structure of the polyimide single-ion polymer is shown as a formula (I). The good thermal stability of polyimide is utilized; in addition, each repeating unit of the obtained polyimide skeleton contains two trifluoromethyl groups (-CF3), so that the polymer hasgood solubility; 3-chloropropane sulfonyl lithium (trifluoromethanesulfonyl) imide lithium salt is fixed on the polymer through a grafting reaction; low lithium ion dissociation domain energy existing in a lithium bis(sulfonyl) imide part can promote dissociation and transmission of lithium ions in grafted 3-chloropropanesulfonyl lithium (trifluoromethanesulfonyl) imide lithium salt, high lithiumion conductivity of the polymer electrolyte is ensured, more lithium sources are provided, the migration number of Li<+> of the electrolyte membrane is increased; therefore, the thermal stability andelectrochemical stability of the polymer electrolyte membrane and the cycling stability of a battery are ensured, and the use safety of a lithium ion battery is ensured.