209results about How to "High reversible specific capacity" patented technology

The invention discloses a preparation method of a silicon and carbon-coated graphene composite cathode material. The technical problem to be solved is to enhance the electronic conductivity of the silicon-based cathode material, buffer the volume effect produced in the process of deintercalation of the lithium in the silicon-based cathode material and enhance the structure stability in the circulation process of the material at the same time. The material is prepared by using a spray drying-thermally decomposing treatment process in the invention. The preparation method comprises the following steps of: evenly dispersing nano silicon and graphite micro powder in a dispersion solution of oxidized graphene, carrying out thermal treatment under an inert protection atmosphere after spray drying, subsequently cooling along a furnace to obtain the silicon and carbon-coated graphene composite cathode material. The extra binder does not need to add in the process of manufacturing balls in the invention and the outer oxidized graphene is thermally reduced in situ to graphene in the thermal treatment process of the composite precursor, so that the process is simple and easy to operate; and the practical degree is high. The prepared composite material has the advantages of great reversible capacity, designable capacity, good cycling performance and high-current discharging performance, high tap density and the like.

The invention discloses a silicon-carbon composite material with nano micropores and a preparation method as well as application thereof. The material comprises nano-silicon (Si) particles and a carbon nanofiber matrix, wherein the nano-silicon particles are dispersed in the carbon nanofiber matrix; and nano pores and micropores communicated with the nano pores are distributed in the carbon nanofiber matrix. The method comprises the steps of dissolving the nano-Si particles and polyacrylonitrile (PAN) in a solvent to prepare a mixed spinning solution, then carrying out electrostatic spinning on the mixed spinning solution, and curing spinning trickles in a coagulating bath to obtain a porous PAN-Si composite nanofiber; and then carrying out oxidation and carbonization treatment in sequence to obtain the silicon-carbon composite material with a nano micropore structure. The silicon-carbon composite material is applied to preparation of lithium ion battery cathode materials. Compared with the prior art, the silicon-carbon composite material ensures the overall electron transport capacity of the material while reserving buffer space for expansion of the nano-Si particles.

The invention discloses a lithium battery formed on the basis of lithium nickel manganese oxide and lithium titanate and a preparation method of the lithium battery. The lithium battery comprises an aluminum-plastic film casing, an anode lug, a cathode lug and a tab film, wherein the aluminum-plastic film casing contains a battery cell and electrolyte; the battery cell comprises an anode piece, a diaphragm and a cathode piece; materials of the anode piece comprise an anode slurry coating consisting of a positive active material, a binding agent, a conductive agent and a solvent and an anode current collector; the positive active material adopts an Al2O3 coating of lithium nickel manganese oxide; the binding agent adopts one or two of polyvinylidene fluoride and polytetrafluoroethylene; the conductive agent adopts one or more of conductive carbon black, conductive graphite and carbon nanotubes; the solvent adopts N-methyl-2-pyrrolidinone; the anode current collector adopts an aluminum foil; the cathode piece adopts an aqueous cathode or an oil-based cathode. According to the designed lithium battery, the purposes of improvement of the reversible specific capacity, the energy density and the rapid charge-discharge capability, the cycle performance and the safety performance of the battery are achieved while the production cost is reduced.

Modified graphite includes granules of graphite core material and amorphous carbon membrane layer. Distance of between micro crystal layers d002 as 0.335-0.340 nm. Specific surface area of modified graphite is 1.3-4.2m2/g and average particle diameter is 8-35 micro. The preparing method includes following steps: dipping granules of graphite core material in solution of polymer coating materials; then through mixing, separating, sieving, solidifying and carbonizing steps. Advantages are: large current, higher reversible specific capacity, longer cycle life. Features are simple, low cost and easy for industrialization production.

The invention discloses a phosphorus/carbon composite negative electrode material of a lithium ion battery and a preparation method thereof, which belong to the technical field of electrode materials of the lithium ion batteries and preparation thereof. In the composite material, the mass ratio of P to C is 8/2-4/6, and the composite material has an amorphous structure containing P-C chemical bonds. A phosphorus source material and a carbon source material are mixed according to the mass ratio of the P to the C of 8/2-4/6; then the mixed material is added into a stainless steel tank; stainless steel balls are added into the mixed material according to the mass ratio of the mixed material and the stainless steel balls of 1:20-1:80; and the ball milling is performed for 5 to 30 hours under the protection of nitrogen to obtain the phosphorus/carbon composite material. The phosphorus/carbon composite material has higher reversible specific capacity and good electrochemical cycle stability; and the material has simple process and convenient operation, and is easy to realize mass industrial production.

The invention relates to the technical field of lithium ion batteries, and in particular relates to an anode active material of the lithium ion battery. The molecular formula of the material is shown as Li(1-alpha)A(alpha)[Li(1/3-beta)MI(beta)Mn(2/3-gamma)MII(gamma)]O2-deltaXz. The lithium ion battery manufactured by the anode material has the reversible specific capacity which is higher than 200mAh/g, good circulation and heat stability performances and perfect multiplying power performance. The anode materials can meet requirements of the lithium ion battery effectively, such as the high energy density, the high-power density and the long service life and high safety.

The invention belongs to the technical field of a new energy material, specifically a preparation method of a vanadium tetrasulfide/graphene composite material used for an electrode of a sodium ion battery. By adopting a hydrothermal synthesis method and by adopting layered graphene as a template, vanadium tetrasulfide is grown on the layered graphene template (or vanadium tetrasulfide particles are coated with graphene) so as to form the vanadium tetrasulfide/graphene composite material; the method is simple in process, low in cost, high in repeatability, and suitable for a commercial application of the electrode material of the sodium ion battery; according to the preparation method, by virtue of a graphene thin film sheet layers, the nanometer vanadium tetrasulfide particles are connected between the sheet layers to form a stable solid electrolyte interface film, thereby effectively improving conductivity of the composite electrode material, and showing high rate capability and cycle stability; and the reversible specific capacity in charging and discharging cycles at the current of 0.2A.g<-1> can reach 580mAh.g<-1>, and high-current charging and discharging capability of as high as 20A.g<-1> can be realized, so that the commercial electrode application of the sodium ion battery can be satisfied.

The invention discloses a preparation method of a carbon nanofiber electrode material based on an MOFs derived metal oxide, and belongs to the technical field of lithium ion battery negative electrodematerials. According to the preparation method, an N-N dimethylformamide solution formed by mixing MOFs particles and polyacrylonitrile fibers is adopted as a spinning precursor. The MOFs are connected to the polyacrylonitrile fibers in series through electrostatic spinning, so that a precursor film can be obtained; the MOFs derived metal oxide and carbon nanofiber composite material is preparedthrough subsequent pre-oxidation and carbonization treatment. The MOFs-derived metal oxide can maintain the unique frame structure of the precursor MOF material to be used as a lithium ion memory; thecarbon nanofibers can promote the rapid transfer of electrons so as to improve the conductivity of the electrode material; the metal organic framework (MOFs) derived material (metal oxide) with a unique structure is embedded into the carbon nanofibers, so that a three-dimensional conductive network structure can be formed; and used as a lithium ion battery negative electrode material, the three-dimensional conductive network structure shows relatively high reversible specific capacity and excellent cycle performance.

The invention relates to a lithium secondary battery cathode material and a preparation method thereof, and belongs to the technology of the lithium secondary battery cathode material. The cathode material is prepared from montmorillonite or organic modified montmorillonite, acetylene black and polyvinylidene fluoride. The preparation process of the cathode material comprises the following steps of: mixing the montmorillonite or the organic modified montmorillonite, the acetylene black and the polyvinylidene fluoride in mass ratio; putting the mixture into a mortar for grinding; adding N-methyl pyrrolidone in the mass ratio of the mixture; continuously grinding the mixture, and coating the mixture onto an aluminum foil; and drying the mixture in a blower drying oven and a vacuum drying oven in sequence to obtain the lithium secondary battery cathode material. The prepared lithium secondary battery cathode material has the advantages of high reversible specific capacity, good dimensional stability in the process of charging and discharging, low price, availability, large scale production and wide application prospect.

The invention discloses a nitrogen-doped porous carbon ball/manganic manganous oxide nanometer composite electrode material and a preparation method thereof. The preparation method comprises that chitosan and its derivative as carbon source and nitrogen source predecessors and porous silica as a hard template are carbonized, then silica is removed so that nitrogen-doped porous carbon balls are obtained, manganic manganous oxide nanometer particles grow on the nitrogen-doped porous carbon balls by a mild solvothermal method, and the nitrogen-doped porous carbon balls with the manganic manganous oxide nanometer particles are subjected to centrifugation washing and drying so that the nitrogen-doped porous carbon ball/manganic manganous oxide nanometer composite electrode material is obtained. The prepared material as a lithium ion battery negative electrode material has a high reversible specific capacity, good cycling stability and excellent multiplying power discharge performances. The preparation method can be operated easily, has mild preparation conditions and no harsh requirement on equipment and is suitable for industrial production. The nitrogen-doped porous carbon ball/manganic manganous oxide nanometer composite electrode material has a wide application prospect in the electrochemistry fields of high performance lithium ion batteries and super capacitors.

The invention discloses a lithium ion battery negative electrode material and a preparation method thereof. The material has a core-shell structure; a core material is silicon grains and a shell material is carbon; a gap etched by an alkaline solution is formed between the core material and the shell material, so that the volume effect of the silicon grains can be inhibited to a certain extent, the diffusion distance of lithium ions can also be reduced and the electrochemical reaction speed is enhanced; therefore, the cycle performance of the silicon-based negative electrode material is improved, the structural stability of the material in a cyclic process is improved and the aims of high capacity and high cycle are realized.

The invention discloses a cathode material for a lithium-ion battery, a preparation method of the cathode material and the battery. The material adopts the structure that a lithium-nickel-cobalt-manganese material used as the core is coated with an aluminum-doped lithium-nickel-cobalt-manganese material, the molecular formula of the lithium-nickel-cobalt-manganese material used as the core is Lim(Ni1-x-yCoxMny)O2, the molecular formula of the aluminum-doped lithium-nickel-cobalt-manganese material for coating is Lim(Ni1-x-y-zCoxMnyAlz)O2, m is larger than or equal to 1 and smaller than or equal to 1.4, x is larger than or equal to 0.05 and smaller than or equal to 0.35, y is larger than or equal to 0.1 and smaller than or equal to 0.4, and z is larger than 0 and smaller than or equal to 0.08. A shell layer of the cathode material is doped with aluminum, so that on one hand, the usage amount of cobalt in the whole cathode material adopting the core-shell structure is reduced, and the cost is reduced; on the other hand, corrosion caused by an electrolyte to the lithium-nickel-cobalt-manganese material used as the core can be reduced due to the aluminum in the shell layer, so that the reversible specific capacity of the lithium-ion battery made of the cathode material can be improved, and the cycle performance of the battery can be improved.

The invention belongs to the technical field of lithium-ion batteries, and particularly relates to a fluorine-doped carbon-coated positive electrode composite material and a preparation method and an application thereof. The method comprises the following steps: with a lithium source, a manganese source and/or an iron source and a phosphorus source as materials, obtaining a positive electrode material LiMn<1-x>Fe<x>PO<4> (x=0-1) by a solvothermal method or a solid phase method; and mixing the obtained positive electrode material with a fluorine-containing material and carrying out high-temperature carbonization under inert gas protection to obtain the fluorine-doped carbon-coated positive electrode composite material. According to the fluorine-doped carbon-coated positive electrode composite material, the electron conduction velocity can be accelerated by fluorine-doped carbon; corrosion of an electrolyte to the material LiMn<1-x>Fe<x>PO<4> (x=0-1) is reduced; and the prepared positive electrode material has high reversible specific capacity, good rate capability, excellent cycle performance and high energy density. The technology is simple; the repeatability is good; and the prepared high-performance positive electrode material is suitable for the field of application of lithium-ion power batteries.

The invention discloses a preparation method of a nano-composite membrane electrode material. The preparation method comprises the following steps: (1) dissolving a precursor of manganese, a precursor of titanium and a precursor of carbon in an organic solvent to prepare a spinning solution; (2) performing electrostatic spinning on the spinning solution to obtain a nano-fiber material; and (3) after performing pre-oxidation treatment on the nano-fiber material, performing carbonization treatment in an inert atmosphere to obtain the required nano-composite membrane electrode material. The MnOx/TiO2/C nano-fiber composite membrane electrode material prepared by the preparation method is excellent in performance, nano particles of MnO2 and TiO2 are distributed on carbon nanofibers with good electric conductivity and porous structure in a mutually interlaced manner, and crystal structures of MnO2 and TiO2 nano particles affect each other and the MnO2 and TiO2 nano particles coordinately distribute on the carbon nanofiber membrane , so that the intercalation and deintercalation efficiency of lithium is improved, and the cycle performance and rate performance of the electrode material are improved; and moreover, the porous structure of the carbon nano-fibers provides a passage for the intercalation and deintercalation of lithium ions, and the electric conductivity is improved.

The invention relates to a V2O5 nanoparticle/graphene (V2O5-GE) lithium ion battery positive pole material and a preparation method thereof, belonging to the field of lithium ion battery positive pole materials. The V2O5-GE positive pole material is synthesized by simple hydrothermal reaction, and is a nano composite positive pole material formed by distributing 20-40nm V2O5 nanoparticles on the surface of two-dimensional transparent graphene sheets. Compared with the V2O5 nanoparticles, due to the introduction of the graphene, the V2O5-GE nano composite material has the advantages of excellent electrochemical properties, higher reversible specific capacity, high loop stability and higher rate capability. The graphene nanosheets perform the function of the conductive reticular structure, and improve the conductivity of the composite material electrode; the flexible reticular structure maintains the stability of the electrode material structure and inhibits the particle agglomeration and volume expansion, thereby improving the electrochemical properties of the V2O5 nanoparticles; and the positive pole material is hopeful to be used as a high-performance lithium ion battery positive pole material.

The invention discloses a membrane electrode based on a spiral carbon nanofiber bundle and a preparation method thereof, belonging to the technical field of lithium ion batteries. The membrane electrode comprises a copper coil current collector and the spiral carbon nanofiber bundle growing on the surface of the copper coil current collector, wherein the spiral carbon nanofiber bundle is formed by spirally winding a plurality of carbon nanofibers, and a graphite layer of the carbon nanofibers is vertical to the axial direction of the carbon nanofibers. The preparation method of the membrane electrode comprises the following steps: loading a nickel-based catalyst on the surface of a copper coil; and then growing the spiral carbon nanofiber bundle on the surface of the copper coil by adopting a chemical vapor deposition method. The membrane electrode and the preparation method provided by the invention have the advantages that the unique structure of the membrane electrode enables the membrane electrode to have higher reversible specific capacity, good electrochemical cycle stability and higher multiplying power performance; and the preparation technology is simple, convenient to operate, and easy to implement large-scale industrial production.

The invention discloses a nickel lithium manganate-based positive electrode material of a lithium ion battery and a preparation method thereof. A material used for a positive plate comprises a positive electrode current collector and a positive electrode slurry coating which is composed of a positive electrode active substance, a binder, a conductive agent and a solvent, wherein the positive electrode active substance is an Al2O3 coating of nickel lithium manganate, the binder is one or more selected from the group consisting of polyvinylidene fluoride and polytetrafluoroethylene, the conductive agent is one or more selected from the group consisting of conductive carbon black, conductive graphite and a carbon nanotube, the solvent is N-methylpyrrolidone, and the positive electrode current collector employs an aluminum foil. The lithium ion battery designed in the invention has reduced cost, and the purposes of improving reversible specific capacity, energy density, rapid charging and discharging capability, cycle performance and safety performance are achieved.

The invention relates to an anode material for a lithium ion battery and a preparation method thereof, and in particular to a preparation method of micro-sodium ion doped high voltage lithium cobalt oxide, and belongs to the field of anode material for the lithium ion battery. The anode material for the lithium ion battery is lithium cobalt oxide doped by more than two metal elements. The chemical general formula of the anode material is Li(1-y)NayCo(1-x)MxO2, wherein y is greater than or equal to 0.0001 but less than or equal to 0.01, x is greater than 0 but less than or equal to 0.5, and M represents one or more of Al, Mg, Zr, Mn, Ni, Ti, Cr, Nb, Y, Cu, Sn, Sc, Ga, In, Ce and La. By doping the metal M, the cyclic stability of the lithium cobalt oxide material is improved; by doping the micro-sodium ions, the specific capacity of the material is improved on the basis of improvement of the cyclic stability of the lithium cobalt oxide material.

The invention provides an O3 type sodium ion battery cathode material and a preparation method thereof. The preparation method comprises the following steps: firstly preparing metal salt of nickel, manganese, iron, and aluminum into a precursor solution; performing spraying pyrolysis on the precursor solution to obtain powder product; and finally uniformly mixing the powder material and the sodiumsalt to perform tabletting and high-temperature sintering to obtain the O3 type sodium ion battery cathode material. The preparation method is simple in operation, high in production efficiency, large in capacity, and strong in adaptability. The manufactured cathode material is a sheet structure, the sheet diameter is 1-5 microns, the thickness is 0.5-0.1 micron, the morphology and particle sizeis uniform, the reversible specific capacity under high voltage is high, the cycling stability is good; the charging/discharging specific capacity is measured in the 2.0-4.2V voltage interval, the first discharging specific capacity is more than 148mAh.g-1, and the coulombic efficiency is more than 92%.

The invention provides a high-capacity potassium ion battery negative electrode material and a preparation method and application thereof. A potassium ion battery prepared from a nano SnS2/graphene composite electrode material can obtain the high reversible specific capacity of 714 mAh/g, and has excellent rate capability and cycle performance. Under the condition that the current density is 500 mA/g, the battery can still give play to the reversible capacity of 483 mA/g; under the condition of 50 circles of circulation at the current density of 250 mA/g, the reversible capacity of 464 mAh/g can still be kept, and the bottleneck problem of low capacity of a conventional potassium ion battery is effectively solved.

The invention discloses a preparation method of a silicon-carbon negative electrode of a lithium ion battery. The preparation method comprises the following steps: weighing a proper amount of nano silicon powder, a dispersing agent and an organic carbon source, and dispersing the nano silicon powder, the dispersing agent and the organic carbon source in absolute ethyl alcohol to obtain mixed solution; adding graphene and Ketjen black into absolute ethyl alcohol to obtain mixed solution after dispersing; dispersing the two types of mixed solution to obtain precursor mixed solution; fully dryingthe obtained precursor solution to obtain powder particles, and carrying out high-temperature carbonization on the powder particles to obtain a silicon-carbon composite material; and uniformly mixingthe obtained silicon-carbon composite material with other carbon materials according to a certain ratio to obtain the silicon-carbon negative electrode material of the lithium ion battery. Accordingto the invention, the nano silicon particles are uniformly coated by graphene and Ketjen black, thereby avoiding the side reaction between the silicon negative electrode and the electrolyte, improvingthe cycle efficiency of the lithium battery, and solving the problem that the discharge capacity and the cycle capacity of the battery are reduced due to the side reaction between nano silicon particles and the electrolyte caused by direct mixing of graphene by the negative electrode material of the existing lithium battery.

The method consists of procedures of solid phase synthesis and burning in high temperature including following steps. (1) According to lithium: cobalt, manganese, nickel=1-1.1 : 1 (atomic ratio), and cobalt : manganese : nickel=1:1:1, polyacrylamide and neodymia are added into even mixed sources of cobalt, manganese, nickel. The above admixture is mixed round evenly till it becoming colloid. (2) Baking drys the said colloid for 30 hr. under 150 deg.C, and ball milling is carried out till powder is passed through sieve. (3) With being preburned for 10 hr. at 300-450 deg.C, the said powder is cooled to room temperature. (4) Product is obtained after fine ball milling the preburned powder, passing through sieve, burning and sifting the powder by 300 screen mesh again. Comparing with prior art, the invented method adds polyacrylamide and neodymia as well as preburning step so as to possess features of high specific capacity, good cycle performance and pollution-free.