1108results about How to "High specific capacity" patented technology

An electrochemical cell comprising an anode, electrolyte or an electrolyte/separator combination, and a nano-structured cathode, wherein the cathode comprises: (a) an integrated nano-structure of electrically conductive nanometer-scaled filaments that are interconnected to form a porous network of electron-conducting paths comprising pores with a size smaller than 100 nm (preferably smaller than 10 nm), wherein the filaments have a transverse dimension less than 500 nm (preferably less than 100 nm); and (b) powder or salt of lithium-containing sulfide (lithium polysulfide) disposed in the pores, or a thin coating of lithium-containing sulfide deposited on a nano-scaled filament surface wherein the lithium-containing sulfide is in contact with, dispersed in, or dissolved in electrolyte liquid and the lithium-containing sulfide-to-filament weight ratio is between 1/10 and 10/1 which is measured when the cell is in a fully discharged state. The cell exhibits an exceptionally high specific energy and a long cycle life.

This invention provides a nano-structured anode composition for a lithium metal cell. The composition comprises: (a) an integrated structure of electrically conductive nanometer-scaled filaments that are interconnected to form a porous network of electron-conducting paths comprising interconnected pores, wherein the nano-filaments have a transverse dimension less than 500 nm; and (b) micron- or nanometer-scaled particles of lithium, a lithium alloy, or a lithium-containing compound wherein at least one of the particles is surface-passivated or stabilized and the weight fraction of these particles is between 1% and 99% based on the total weight of these particles and the integrated structure together. Also provided is a lithium metal cell or battery, or lithium-air cell or battery, comprising such an anode. The battery exhibits an exceptionally high specific capacity, an excellent reversible capacity, and a long cycle life.

The invention provides a method for cladding surfaces of an active material of an anode and/or the anode and methods for manufacturing the anode and a battery. In the cladding method, an atomic layer deposition technology is adopted to deposit surface modification substances on the surfaces of the active material of the anode and/or the anode of a lithium battery. According to the invention, the cycle performance and the specific capacity of the lithium-ion battery can be improved obviously and electrode materials are more stable.

The invention discloses a grapheme/silicon composite material for a lithium ion battery cathode material and a preparation method thereof, belonging to the fields of electrochemistry and new energy materials. The method comprises the following steps of: using graphite as a raw material; oxidizing the graphite into oxidized graphite by adopting oxidants of concentrated sulfuric acid and potassium permanganate; then, ultrasonically stripping the oxidized graphite to prepare oxidized graphene; mixing oxidized graphene in different proportions with nano silicon powder; ultrasonically dispersing, filtering or directly drying into a cake/film; and roasting under a reduction atmosphere to prepare self-support graphene/silicon composite film materials in different proportions. Proved by electrochemistry tests, the graphene/silicon composite film material prepared by the method has higher specific capacity and cycle stability, simple preparation method and easy mass production and consequently is an ideal high-energy lithium ion battery cathode material.

A preparation method of a high power capacity lithium ion battery cathode material uses natural spherical graphite to serve as raw materials, uses concentrated sulfuric acid to serve as an inserting layer agent, uses potassium permanganate to serve as an oxidizing agent, conducts expansion treatment at high temperature to obtain micro-expanded graphite, then enables the micro-expanded graphite in different proportions to be mixed with nanometer ganister sand, conducts ultrasonic dispersion, suction filtration and dying to obtain the micro-expanded graphite with the nanometer ganister sand inserted in layers, enables the micro-expanded graphite to be mixed and coated with carbon source carbon source according to certain proportion, and finally conducts carburizing sintering under inert gas shielding to prepare completely coated silicon carbon composite cathode material with sufficient obligated obligate inside. Electrochemistry shows that the silicon carbon composite material prepared by the preparation method has high specific capacity and cycling stability and is the ideal high power capacity lithium ion battery cathode material.

The invention discloses an oxidized grapheme/polyaniline super capacitor composite electrode material and the preparation method and the application thereof. The preparation method comprise the following steps: firstly, adding oxidized graphite to water for ultrasonic dispersion so as to form an oxidized grapheme solution with uniformly dispersed single pieces; at room temperature, dropping aniline to the obtained oxidized grapheme solution for continuous ultrasonic dispersion to from a mixed solution; at a low temperature condition, adding hydrogen peroxide, ferric trichloride and a hydrochloric acid solution dropwise to the mixed solution, and stirring the solution for polymerization; and after the reaction is finished, centrifugating, washing and roasting the obtained mixed solution in vacuum to obtain the oxidized grapheme/polyaniline super capacitor composite electrode material which is used as the electrode material of an electricity storage system of a super capacitor and a battery. The oxidized grapheme/polyaniline super capacitor composite electrode material with good electrochemistry performance is obtained by the method, and the specific capacity of the oxidized grapheme and the polyaniline is greatly improved. In addition, the addition of the oxidized grapheme improves the charge and discharge service life of the polyaniline.

The invention relates to a spinel nickel manganese acid lithium and layered lithium-rich manganese-based composite cathode material with a core-shell structure and a preparation method thereof, which belongs to the technical field of material synthesis. The prepared lithium ion composite cathode material takes a layered lithium-rich manganese-based Li[Lia(NixCoyMnz)]O2 as a core material, takes spinel nickel manganese acid lithium LiNi0.5Mn1.5O4 as a shell material; a coprecipitation method is employed to obtain a core-shell precursor, the core-shell precursor and the lithium source are uniformly mixed and calcined to obtain the spinel nickel manganese acid lithium and layered lithium-rich manganese-based composite cathode material with the core-shell structure. According to the invention, the layered lithium-rich manganese-based is taken as the core material, and the spinel nickel manganese acid lithium is taken as the shell material; under the prerequisite that material gram capacity is kept, material structural stability is increased, material cycle, multiplying power and safety performances are improved, function composite and complementation of the core material and the shell layer material can be realized, and the problem that high capacity and high security can not be achieved simultaneously is solved. The composite cathode material has the advantages of simple process and obviously increased performance.

The invention relates to the field of negative electrode materials of lithium ion batteries, and specifically to a nanometer lithium titanate/graphene composite negative electrode material and a preparation process thereof. According to the invention, micron-sized lithium titanate prepared by the solid phase method is subjected to ultrafine ball milling to obtain nanometer powder, and the nanometer lithium titanate powder and graphene are uniformly compounded and subjected to heat treatment so as to obtain a high performance lithium ion battery negative electrode material; the invention is characterized in that uniform distribution of graphene in the nanometer lithium titanate powder is realized through in situ compounding; the weight of graphene in the composite negative electrode material accounts for 0.5 to 20%, and the weight of lithium titanate accounts for 80 to 99.5%. The lithium ion battery negative electrode material has good electrochemical performance, 1C capacity greater than 165 mAh/g, 30C capacity greater than 120 mAh/g and 50C capacity greater than 90 mAh/g. Nanometer lithium titanate in the lithium ion battery negative electrode material prepared in the invention has high phase purity; the preparation process of the material is simple and is easy for industrial production.

The present application discloses a metal lithium-framework carbon composite material preparation method, which comprises: uniformly mixing metal lithium having a molten state and a porous carbon material carrier, and cooling to obtain the metal lithium-framework carbon composite material. The invention further discloses a metal lithium-framework carbon composite material, a secondary battery negative electrode, a secondary battery and a metal-framework carbon composite material. According to the present invention, with the prepared metal lithium-framework carbon composite material, the dendritic crystal formation can be inhibited, the whole property of the battery can be improved, and the high specific capacity and the good cycle performance are provided.

The invention relates to a synthesis and surface modification method of a lithium rich anode material Li1+xM1-xO2 (M is one or more of Ni, Co and Mn, and X is more than or equal to 0 and less than or equal to 1/3) for a lithium ion battery. The method comprises the following steps of: synthesizing a precursor by using a carbonate precipitation method, mixing the precursor and a lithium salt, and calcining for 2 to 20 hours at the temperature of between 800 and 1,100 EG C to obtain a lithium rich material, wherein the prepared lithium rich material has controllable particle size and higher reversible capacity; and dissolving persulfate or sulfate in an amount which is 5 to 80 mass percent of the lithium rich material into deionized water, adding the lithium rich material, stirring for 2 to 100 hours at the temperature of between 25 and 80 DEG C, heating the materials to the temperature of between 100 and 500 DEG C in a muffle furnace, calcining the materials for 2 to 20 hours, fully filtering the obtained materials, and washing off impurities to obtain the surface modified anode material Li1+x-yM1-xO2. The synthesized lithium rich material has controllable particle size; the first charge/discharge efficiency of the lithium rich material and the discharge specific capacity and the cyclical stability under high magnification can be improved; and the method is simple, low in cost, convenient for operation and suitable for industrialized production.

The invention relates to the technical field of lithium-ion cathode material, in particular to silicon cathode material coated with graphene and a preparation method of the silicon cathode material coated with the grapheme. The preparation method comprises the following steps: A, preparing oxidized graphene suspension liquid; B, preparing nanometer silicon particle suspension liquid; and C, preparing silicon cathode material coated with grapheme. The preparation method adopts the electrostatic self-assembly synthetic technology and is wide in source of raw material, low in price, simple in synthetic method, easy for control of process conditions, strong in operability and good in repeatability. The silicon cathode material coated with grapheme is high in specific capacity and good in cycle performance and rate capability, wherein the specific discharge capacity for the first time under the electric current density of 0.01-1.2V, 200mA/g can reach 2746mAh/g, and the specific discharge capacity after 100 times of cycles can maintain 803.8mAh/g.

The invention discloses a carbon coated sulfur-based anode composite material in the field of lithium sulfur batteries. The composite material comprises a sulfur-based anode material and amorphous carbon, wherein the amorphous carbon is uniformly and compactly coated on the surface of the sulfur-based anode material, the particle diameter of the sulfur-based anode material is 10 nanometers to 10 microns, and the thickness of the amorphous carbon layer is 1 to 5 nanometers. The invention also discloses an anode, which comprises a current corrector and an anode material supported on the current corrector, wherein the anode material comprises an anode active substance, anode adhesive and a conductive component; and the anode active substance is the carbon coated sulfur-based anode material. The anode is adopted for preparing a corresponding lithium sulfur battery; the amorphous carbon is coated on the surface of the sulfur-based anode active material so as to remarkably improve the electric conductivity of the anode material, and the lithium sulfur battery adopting the anode has high specific capacity and good cycle performance; and the preparation process is simple and suitable for large-scale industrialized production.

The invention discloses a preparation method of a high density nickel cobalt lithium manganate positive electrode material, LiNixCoyMnzO2. The preparation method comprises the following steps: firstly, mixing a nickel salt solution, a cobalt salt solution and a manganese salt solution according to a certain mol ratio, adding the mixed solution, a complexing agent solution and a precipitant solution together to a stirring reaction kettle with a base solution, fully reacting, carrying out solid-liquid separation, and washing and drying to obtain a globular nickel cobalt manganese oxyhydroxide precursor; calcining the precursor at the temperature of 350-900 DEG C for 2-20 hours to obtain a globular nickel cobalt manganese oxide precursor, and smashing the globular nickel cobalt manganese oxide precursor at high speed to obtain a mono-crystalline nickel cobalt manganese oxide precursor; mixing a lithium source and the mono-crystalline precursor according to a certain mol ratio, calcining at the temperature of 700-980 DEG C for 2-20 hours, and smashing and classing to obtain the mono-crystalline nickel cobalt lithium manganate positive electrode material. The preparation method provided by the invention has the advantages that the compacted density of the prepared nickel cobalt lithium manganate material is large, the specific capacity is high, the rate property and consistency are good, the preparation method is simple, and the preparation process is easy to control and operate.

The invention discloses a novel lithium iron phosphate material which is adulterated /covered with conductive agents and a preparation method thereof. The lithium iron phosphate material of the invention comprises lithium source compounds, iron source compounds, phosphate radical source compounds and the conductive agents of lithium iron phosphates. The technology of the invention is simple; the material is clean and pollution-free; the cost of the material is low. The invention is suitable for industrialized mass production. Specific capacity of the obtained lithium iron phosphate material is high (more than 140 mAh/g); cyclical stability is good (more than 300 times); high rate charging and discharging performance of the lithium iron phosphate material is particularly prominent (5C capacity can still reach 80 mAh/g); conductivity and stacking density are high; diffusivity of protons is improved; contact between active materials and an electrode is increased; internal resistance of the electrode and a battery is reduced; discharging and cyclical stabilities of the electrode are obviously improved. The invention is widely applied to novel high performance lithium ion batteries.

The invention discloses a method for preparing a nitrogen-doped carbonaceous material by modifying polymer, which can be used for preparing the nitrogen-doped carbonaceous material with the nitrogen doping amount of 5 to 26 at%. The method disclosed by the invention is characterized by comprising the following steps of: selecting a nitrogen-containing organic compound as a nitrogen precursor and utilizing the nitrogen-containing organic compound to perform polymerization reaction on a carbonaceous material to form a compound of the nitrogen-containing polymer and carbonaceous material; and then carrying out heat treatment on the polymer/carbonaceous material compound in the inert atmosphere to carbonize nitrogen-containing polymer in the compound so as to implement the nitrogen doping on the carbonaceous material and prepare the nitrogen-doped carbonaceous material. According to the invention, when the carbonaceous material is subjected to effective nitrogen doping, the original intrinsic structure of the carbonaceous material can be ensured; moreover, the nitrogen-doped carbonaceous material with the nitrogen content of 5 to 26 at% can be prepared; the specific capacity of using a carbon material as an electrode material of a supercapacitor is obviously improved; and the method has the characteristics of simple technical process and wide applicability.

The invention relates to a lithium ion battery conducting material and a preparation method and application thereof. A graphene lithium ion battery conducting material is prepared by adopting a graphite oxide rapid heat expansion method and has high aspect ratio, which is beneficial to shortening the migration distance of lithium ions and improving the wetting quality of an electrolyte, thereby, the rate performance of an electrode is improved; the graphene lithium ion battery conducting material also has high conductivity and can ensure that an electrode active substance has higher utilization ratio and excellent cyclical stability. Compared with a common acetylene black conductive agent under the same using amount, the specific capacity of a lithium ion battery cathode constructed by the conducting material is improved by 25-40 percent, and the coulomb efficiency is improved by 10-15 percent. In addition, the method has low cost, simple process, high security and low energy consumption and is suitable for large-scale production.

The invention discloses a method for preparing polyaniline coating Li-ion battery anode material LiFePO4. The method is coating polyaniline on the in-situ surface of the powder of Li-ion battery anode material LiFePO4. The method has the following favorable effects: the discharging voltage platform of the polyaniline coating anode material LiFePO4obtained is stable, the battery has higher specific capacity up to one hundred and forty point three mAh/g, the granularity is distributed evenly, the grains are in good appearance and high in discharging capacity and long in cycling life, etc.

The invention provides a method for preparing lithium iron phosphate/nanometer carbon composite anode material, which is characterized by comprising the steps as follows: 1) a precursor is pretreated, raw materials are weighed according to the components and weight percentage as follows: 0.2%-15% of catalyst, 5%-15% of lithium salt, 40%-60% of iron salt and 25%-45% of phosphate; the catalyst is one or several kinds of metal Fe, Co and Ni; the raw materials are added with dispersant and then are ball-milled in a ball grinder to prepare the precursor; 2) a carbon nano tube or carbon fiber grows; and 3) lithium iron phosphate or adulterant lithium iron phosphate is prepared. The invention solves the problem that the carbon nano tube is difficult to be dispersed in high-viscosity high-solid lithium iron phosphate slurry, and the invention provides the method for growing the carbon nano tube or the carbon fiber synchronously during the process of preparing the lithium iron phosphate and improves the specific capacity and the cycle life of the lithium iron phosphate under the condition of charging and discharging.

The invention discloses a porous carbon electrode material based on chitosan and a derivative of chitosan as well as a preparation method and application of the porous carbon electrode material. According to a hard template carbonization method, by taking a hollow silicon oxide ball as a template and taking chitosan and a derivative of chitosan as carbon source precursors, liquid-phase impregnation, high-temperature carbonization, template removing and the like are carried out so as to obtain the porous carbon electrode material suitable for a lithium ion battery and a supercapacitor. The prepared porous carbon electrode material simultaneously has the characteristics of a nitrogen-doped structure and a macroporous-mesoporous-microporous graded pore structure, wherein the nitrogen-doped content can be controlled by using different types of chitosans; the graded pore structure can be controlled by changing the size of the particle diameter and the wall thickness of each silicon oxide ball and regulating the mass of the chitosan solution. Compared with the commercialized graphite, the porous carbon electrode material prepared according to the method disclosed by the invention has the advantages that the specific capacity is obviously increased and the rate performance of the obtained porous carbon electrode material is maintained well. The porous carbon electrode material is simple in preparation process, has no strict requirement to equipment and is suitable for industrial production.

The invention discloses a silicon/graphene composite material, and a preparation method and an application of the same. The preparation method comprises the following steps of: ultrasonically mixing silicon source and graphite oxide to be uniform in water, performing freeze drying to obtain freeze-dried powder, and then, placing the powder in non-oxidizing atmosphere for performing a reduction reaction, after the reduction reaction, obtaining the silicon/graphene composite material. The method can form the composite material by two steps, and templates are not needed, so that the method has high practicability, the obtained silicon/graphene composite material collects the advantages of a graphite-based composite material and a porous material, and the problems of low specific capacity, poor circulation property and discharge capability and low coulombic efficiency caused by taking a silicon-based material as the cathode material of a lithium ion battery are resolved.

The invention discloses a high-voltage lithium cobalt oxide cathode material for a lithium-ion battery and a preparation method of the high-voltage lithium cobalt oxide cathode material. The high-voltage lithium cobalt oxide cathode material is prepared from a doped lithium cobalt oxide matrix and a coating on the surface of the doped lithium cobalt oxide matrix, wherein a general formula of the doped lithium cobalt oxide matrix is Li<x>Co<1-y>M<y>O<2-z>N<z>; the general formula of the coating is LiNi<x'>Co<y'>Al<z'>O<2>; and the preparation method comprises the following steps: firstly, obtaining the lithium cobalt oxide matrix Li<x>Co<1-y>M<y>O<2-z>N<z> through once sintering; secondly, preparing a lithium cobalt oxide cathode material precursor coated with Ni<x'>Co<y'>Al<z'>(OH)<2> on the surface by liquid-phase co-precipitation reaction; and finally obtaining the high-voltage lithium cobalt oxide cathode material through twice sintering. The high-voltage lithium cobalt oxide cathode material prepared by the method is good in processability and high in compaction density, has relatively high specific capacity and good cycle performance in a high-voltage state, and can be stably circulated at high voltage of 3.0V to 4.5V.

The invention discloses an iron lithium manganese phosphate composite positive electrode material used in a lithium ion battery, and a preparation method thereof. The method provided by the invention is mainly aimed at improving the performance of a lithium ion battery positive electrode material. The method comprises specific steps that: a lithium source is mixed with an iron source, a manganesesource, a phosphorous source, a reducing agent, and doped elements; the mixture is subject to a reaction, such that a compound of an iron lithium manganese phosphate precursor, a lithium source, manganese phosphate, ferric phosphate, phosphate and doped elements is prepared; the compound is mixed with a lithium source and a reducing agent carbon source; and the mixture is sintered under a protective atmosphere, such that the iron lithium manganese phosphate composite positive electrode material is obtained. The method provided by the invention is advantaged in simple technology, low material cost, low production cost, short production period, and low energy consumption. The method can be applied in large-scale productions. The product prepared with the method is advantaged in high bulk density, good conductivity and high specific capacity.

The invention discloses a spherical silicon-oxygen-carbon negative electrode composite material, which is of a three-layer structure comprising an inner layer, an intermediate layer and an outer layer, wherein the inner layer is an SiOx/graphite substrate; the intermediate layer is an amorphous carbon coating layer; the outer layer is a carbon nanotube coating layer; the mass of the inner layer SiOx/graphite substrate accounts for 80%-90% of total mass of the spherical silicon-oxygen-carbon negative electrode composite material; the mass of the intermediate layer amorphous carbon accounts for 5%-10% of total mass of the spherical silicon-oxygen-carbon negative electrode composite material; and the outer layer carbon nanotube accounts for 5%-10% of total mass of the spherical silicon-oxygen-carbon negative electrode composite material. The grain diameter of the adopted SiOx substrate is smaller than 5 microns; the grain diameter is relatively small; intercalation and deintercalation of active substances are facilitated; higher specific capacity can be obtained; meanwhile, a dispersing agent is added when an SiOx sample is ground; and condition that the SiOx with a relatively small grain diameter is agglomerated in quantity to affect the performance is prevented.

The invention discloses a three-dimensional porous quasi-graphene loaded molybdenum disulfide composite and a preparation method thereof. The composite is prepared by uniformly loading large-area ultrathin molybdenum disulfide nanosheets onto the surface of three-dimensional porous quasi-graphene network. The preparation method comprises the following steps: with NaCl as a dispersant and template, fully dissolving and mixing NaCl, a molybdenum source and a sulfur source and carrying out freeze drying and porphyrization so as to obtain a mixture; putting the mixture in a tubular furnace and carrying out calcining under the protection of argon so as to obtain a calcined product A; and washing the calcined product A and drying the washed calcined product A so as to obtain the three-dimensional porous quasi-graphene loaded molybdenum disulfide composite. The invention has the following advantages: preparation process is safe and harmless, operation is simple, and yield is high; and the prepared three-dimensional porous quasi-graphene loaded molybdenum disulfide composite has good reversible capacity, cycle stability and rate capability as a cathode material of a lithium ion battery.

The invention discloses a process of coprecipitation-combustion synthesis of nickel cobalt manganese lithium carbonate. (1) Utilizing acetate or nitrate of nickel, cobalt, and manganese as transition metal source and ammonia as complexing agent and utilizing H2C2O4, (NH4)3C2O4, (NH4)2CO3 or NH4HCO3 as precipitator, compound carbonate contained Ni-Co-Mn or oxalate precursors is synthesized by coprecipitation method. (2) Directly drying the compound carbonate containing Ni-Co-Mn or the suspension liquid of the oxalate and adding lithium nitrate or lithium acetate or a small quantity of water or ethanol to adjust into rheological phase. (3) Laying the materials in rheological phase in an electric stove to perform burning synthesis reaction, wherein the electric stove heats the materials in rheological phase at temperature of 400-600DEG C and then keeps constant temperature. (4) Temper drawing the reaction product with temperature of 600-1200DEG C, and anode active materials of lithium ion battery LiNixCoyMn1-x-yO2 is obtained. The invention has the advantages of simple technique, easy operation, saving water and energy and environment-friendliness, further, the synthetic material is provided with the shape of sphere or near-sphere, high specific capacity and fine cycle performance.

The invention relates to a water-based zinc-manganese single flow battery; a positive electrode active material is an oxide of manganese, a metal composite oxide, a metal oxide or a carbon material, a negative electrode is a zinc electrode, an electrolyte solution is a nearly neutral aqueous solution containing a zinc salt and a manganese salt, positive electrode active ions and negative electrode active ions can coexist in one electrolyte solution, and an ion exchange membrane is not required for separating the positive electrode and the negative electrode; in processes of charging and discharging, the electrolyte solution constantly flows between an electrolyte solution storage tank and an electric pile through a pipeline under pushing of a liquid pump. During charging, zinc ions are deposited onto a negative electrode current collector from the electrolyte solution, the zinc ions and manganese ions are co-embedded into the positive electrode active substance at the same time, and the manganese ions are subjected to oxidation deposition; during discharging, the negative electrode deposited zinc is dissolved into the electrolyte solution, and the positive electrode manganese oxide is partially reduced and dissolved and is extricated to the electrolyte solution with the zinc ions simultaneously. The battery has the outstanding characteristics of simple manufacture, relatively high specific energy and specific power, low cost, long cycle life, environmental friendly and the like, and is widely applied in electric power, transportation, electronics and other fields.

The invention provides a lithium manganate composite positive electrode material, a preparing method thereof and a lithium-ion battery. The composite positive electrode material is of a core-shell structure. The inner layer of the composite positive electrode material is an in-situ composite of lithium manganate and nickel-rich concentration gradient type nickel cobalt manganese/lithium aluminate LiMn2O4-LiNi1-x-yCox(Al/Mn)yO2, wherein x is more than 0 and less than or equal to 0.25, and y is more than 0 and less than or equal to 0.15; the outer shell of the composite positive electrode material is a metal oxide coated layer. According to the lithium manganate composite positive electrode material and the preparing method thereof, the in-situ composite of lithium manganate and nickel-rich concentration gradient type nickel cobalt manganese/lithium aluminate is obtained after in-site sintering of a manganese source, a nickel-rich concentration gradient type nickel cobalt manganese/lithium aluminate precursor, and a lithium source, then shell-layer metal oxide is cladded by using spray drying, and finally the composite positive electrode material is obtained by combining a microwave sintering process. The composite positive electrode material provided by the invention has relatively high specific capacity, and excellent high temperature cycling and storage performances.

The invention discloses a polyimide-based composite electrode material and a preparation method thereof. The electrode material comprises polyimide and a carbon-based material, wherein the polyimide is distributed in the carbon-based material in a nanosheet or nano-particle form. The provided material is used for preparing a lithium ion battery whose positive electrode has high specific capacity, and the material has good stability and flexibility and is suitable for manufacturing a flexible electrode; and the method is simple and suitable for preparing electrode materials on a large scale.

The invention discloses a preparation method of a metal sulfide and carbon composite material and application of the metal sulfide and carbon composite material in a sodium ion battery. Sulfide mainly comprises FeS, CuS, NiS, CdS, SnS2, SnS, Sb2S3, Bi2S3 and the like. The composite material is prepared from metal sulfide and C through a compounding method. Sulfide accounts for 40 to 80 percent of the weight of the material. According to the preparation method of the metal sulfide and carbon composite material, different methods are adopted to introduce a sulfur source and an electrospinning method is adopted to prepare the metal sulfide and carbon composite material; and the introduction of the sulfur source is realized respectively through in-situ introduction and post-treatment method. The metal sulfide and carbon composite material prepared through the preparation method is used as a sodium ion battery anode material, has the advantages of high specific capacity and high circulating stability and is low in manufacturing cost and suitable for large-scale development and application of the sodium ion battery.

The invention provides a preparation method for forming an electrode sheet on a flexible MXene self-supporting membrane through electroplating micro-nanometer metal particles. The invention belongs tothe preparation field of battery negative electrode materials. The technical scheme adopted by the invention is as follows: (1) etching stripping MAX with lithium fluoride and hydrochloric acid, centrifuging, washing, shaking and recentrifuging to obtain MXene suspension. (2) Flexible MXene self-supporting membrane was obtained by vacuum filtration. (3) Plating a layer of micro/nanometer metal particles on MXene film in electroplating bath at constant current or voltage. The flexible MXene self-supporting membrane prepared by the invention has good mechanical properties, It can not only simplify the process, save the cost and meet the needs of industrialization, but also can be used as negative electrode material to obtain batteries with high specific capacity, good cycling stability andbetter conductivity.