2108results about How to "Improve electronic conductivity" patented technology

A lithium metal oxide positive electrode for a non-aqueous lithium cell is disclosed. The cell is prepared in its initial discharged state and has a general formula xLiMO2.(1-x)Li2M′O3 in which 0<x<1, and where M is more than one ion with an average trivalent oxidation state and with at least one ion being Ni, and where M′ is one or more ions with an average tetravalent oxidation state. Complete cells or batteries are disclosed with anode, cathode and electrolyte as are batteries of several cells connected in parallel or series or both.

An active material powder mixture for batteries or a carbonaceous material powder mixture for electrical double-layer capacitors is composed of a battery active material or a carbonaceous material in combination with an electrically conductive powder that adheres to the periphery of the active material or carbonaceous material and has an average particle size of 10 nm to 10 mupm. The battery active material powder mixture may be used to make electrodes for secondary batteries. The carbonaceous material powder mixture may be used to make polarizable electrodes for electrical double-layer capacitors. Secondary cells produced using the active material powder mixture can lower an impedance of an electrode and operate at a high capacity and a high current, have a high rate property, and are thus well-suited for use as lithium secondary cells and lithium ion secondary cells. Electrical double-layer capacitors made using the carbonaceous material powder mixture have a high output voltage and a high capacity because of a low impedance.

The invention relates to a graphene composite lithium ion battery anode material lithium iron phosphate and a preparation method thereof. The composite material of lithium iron phosphate and graphene is connected by interface of chemical bonding. The invention also provides the method for preparing the graphene composite lithium ion battery anode material lithium iron phosphate in an in-situ symbiosis reaction mode, and the obtained anode material has high tap density and good magnifying performance, and is suitable to be used as a anode material of a lithium ion power battery.

A lithium metal oxide positive electrode for a non-aqueous lithium cell is disclosed. The cell is prepared in its initial discharged state and has a general formula xLiMO2.(1−x)Li2M′O3 in which 0<x<1, and where M is one or more ion with an average trivalent oxidation state and with at least one ion being Mn or Ni, and where M′ is one or more ion with an average tetravalent oxidation state. Complete cells or batteries are disclosed with anode, cathode and electrolyte as are batteries of several cells connected in parallel or series or both.

A composite electrode is created by forming a thin conformal coating of mixed metal oxides on a highly porous carbon structure. The highly porous carbon structure performs a role in the synthesis of the mixed oxide coating and in providing a three-dimensional, electronically conductive substrate supporting the thin coating of mixed metal oxides. The metal oxide mixture shall include two or more metal oxides. The composite electrode, a process for producing said composite electrode, an electrochemical capacitor and an electrochemical secondary (rechargeable) battery using said composite electrode are disclosed.

A composite particle for an electrode including an active material particle, carbon nanofibers bonded to the surface of the active material particle, and a catalyst element for promoting the growth of the carbon nanofibers, wherein the active material particle includes an electrochemically active phase. As the catalyst element, for example, Au, Ag, Pt, Ru, Ir, Cu, Fe, Co, Ni, Mo, Mn and the like are used. The composite particle for an electrode may be produced, for example, by means of a method which includes: a step of preparing an active material particle including a catalyst element for promoting the growth of carbon nanofibers at least in the surface layer of the active material particle; and a step of growing carbon nanofibers on the surface of the active material particle in an atmosphere including a raw material gas.

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.

A functionally improved battery is disclosed. The battery includes a flexible thin layer open liquid state electrochemical cell (10) and an electronic chip device (60) integrally formed on or within the electrochemical cell (10). The cell (10) includes a first layer of insoluble negative pole (14), a second layer of insoluble positive pole (16) and a third layer of aqueous electrolyte (12). The third layer (12) is disposed between the first (14) and second (16) layers. The third layer (12) includes a diliquescent material for keeping the cell wet, an electroactive soluble material for ionic conductivity and a watersoluble polymer for viscosity. The viscosity adheres the first (14) and second (16) layer to the third layer (12). The chip (60) serves to improve the functionality of the battery.

The invention discloses a hydrothermal synthesis method of lithium-ion battery anode material of lithium iron phosphate, relating two kinds of metal phosphate. The steps are as follows: lithium source and phosphorus source are dissolved in water or mixed with water, and added into the reaction autoclave, the quaternary cationic surfactants and the alkylphenols polyoxyethylene ethers nonionic surfactant is also added into the reaction autoclave, the air in the dead volume of the autoclave inside is purged by the inert gas, the autoclave is sealed and heated to 40-50 DEG C with stirring, a feed valve and an exhaust valve are opened, pure ferrous salting liquid is added into the autoclave, and then the autoclave is sealed for the reaction of the material at 140 to 180 DEG C for 30 to 480 minutes; the mixture ratio of the invention is set as follows: the molar ratio of Li, Fe and P is 3.0-3.15:1:1.0-1.15, and then the resultant is filtered, washed, dried and carbon-coated, thus the lithium iron phosphate is obtained. The lithium iron phosphate which is produced by the invention has the advantages that: the electrochemical performance is excellent, the particle size distribution of which the D50 is between 1.5 um to 2 um is even, the phase purity is above 99 percent and the electronic conductivity of the material is improved.

The invention belongs to the technical field of a lithium ion battery, and particularly relates to stabilization lithium metal powder. The stabilization lithium metal powder has a core shell structure; and the core layer is formed by lithium metal and is a composition consisting of an electron good conductor and a lithium ion good conductor. Compared with the prior art, the stabilization lithium metal powder provided by the invention has the advantages that: in the process of performing pre-lithiation of the anode-active material by use of the stabilization lithium metal powder, no limitation is imposed on the pressure of the cold pressing process, the 'dead lithium' disabling lithiation reaction is not produced, and the lithiation efficiency of the lithium metal powder is improved; and moreover, since the shell layer left on the electrode surface has good electron and lithium ion conductivity after the pre-lithiation, the electron and ion conductivity of the anode can be effectively improved so as to improve the electrochemical performance of the battery. In addition, the invention also discloses an anode strip performing pre-lithiation by use of the stabilization lithium metal powder, and a lithium ion battery comprising the anode strip.

An electrode material is created by forming a thin coating or small deposits of metal oxide as an intercalation host on a carbon powder. The carbon powder performs a role in the synthesis of the oxide coating, in providing a three-dimensional, electronically conductive substrate supporting the metal oxide, and as an energy storage contribution material through ion adsorption or intercalation. The metal oxide includes one or more metal oxides. The electrode material, a process for producing said electrode material, an electrochemical capacitor and an electrochemical secondary (rechargeable) battery using said electrode material is disclosed.

The invention discloses a carbon-coated ternary positive electrode material and a preparation method thereof. The preparation method comprises the following steps: S1, preparing a ternary positive electrode material precursor by taking nickel salt, cobalt salt and manganese salt as raw materials; S2, preparing a conductive carbon dispersion system, wherein conductive carbon is dispersed in water containing an organic carbon source; S3, adding the ternary positive electrode material precursor and a lithium compound into the conductive carbon dispersion system, and mixing uniformly to obtain a mixture; S4, drying the mixture under a vacuum condition; S5, carrying out high temperature treatment on the dried mixture under a closed condition or in an inert gas protection atmosphere so as to obtain the carbon-coated ternary positive electrode material. The carbon-coated ternary positive electrode material is uniform in coating, simple to operate, low in cost and high in efficiency; the conductive carbon and the ternary positive electrode material are simultaneously coated with network-shaped amorphous carbon which serves as a conductive medium or a channel of the conductive carbon and the ternary positive electrode material, thereby greatly improving the rate performance of the ternary positive electrode material.

The invention relates to a high-performance lithium ion battery. According to the battery, an electrode material is subjected to a nano-composite treatment of grapheme and polyaniline; an anode current collector comprises aluminium foil; a cathode current collector comprises copper foil; a conductive agent comprises superconducting carbon black, conductive graphite or acetylene black; a binding agent comprises styrene butadiene rubber, carboxymethylcellulose sodium, polytetrafluoroethylene, polyvinylidene difluoride or hydroxy propyl methylcellulose; a electrolyte comprises liquid electrolyte or a polymer electrolyte containing a conductive polymer, a nano-material, or a mixture comprising the conductive polymer and the nano-material; a membrane is subjected to a high temperature resistant insulation coating treatment, or directly adopts a high temperature resistant insulating porous polymer matrix. A preparation process for the high-performance lithium ion battery comprises: material preparing, coating, drying, rolling, slicing, coil winding or sheet stacking, assembling, liquid injecting, formation and capacity distributing. The lithium ion battery provided by the present invention has characteristics of excellent charge and discharge performance at the large rate, small capacity fading, good heat stability, good safety performance and long electrode cycle life, and can be widely applicable for the fields of electric bicycles, electric motorcycles, electric cars and the like.

The invention discloses a preparation method of carbon-coated lithium titanate used for a lithium ion battery; the method comprises the following steps: (1) lithium salt and titanium dioxide are weighted according to proportion, a dispersing agent is added, a ball milling method is used for mixing fully and then the obtained mixture is dried in vacuum, thus obtaining a precursor; (2) the obtained precursor is roasted for 8 to 20 hours at the temperature of 750 to 1000 DEG C so as to prepare lithium titanate; (3) carbon source materials are coated on the surface of the prepared lithium titanate by a dipping and steaming method; and (4) the lithium titanate coated with the carbon source materials is placed in a tubular furnace, and is roasted for 0.5 to 5 hours at the temperature of 750 to 1000 DEG C under the protection of inert gas so as to obtain the carbon-coated lithium titanate. The preparation method of the invention forms chemically coated carbon on the surface of the lithium titanate by the pyrolytic reaction of the carbon-coated materials, and the surface contact of the coated carbon and the lithium titanate material is more firm and tight, thus improving the electron conductivity of the materials greatly and enhancing the charge and discharge performance of magnification of the materials.

The invention discloses a manganese / lithium phosphate of lithium iron battery positive pole material and a production method thereof, the technical issue to be solved is to improve electrochemical performances of the positive pole material. The material of the invention includes substrates of manganese / lithium phosphate which are covered by a carbon material covering layer, the lithium covering the manganese / lithium phosphate behind the carbon material covering layer is spherical and has microscopic characteristics of being near spherical, rhombic, tapered, tabular, layered or / and block-shaped as well as of having 0.5-30 mum long and short axles. The production method comprises the following steps of: production of nanometer particles, liquid phase mixed reaction, production of precursor, sintering treatment, covering organic substances. Compared with the prior art, the invention improves the electron conductivity of the manganese / lithium phosphate by covering with carbon liquid phase, the carbon sufficiently covers active materials to efficiently prevent particle aggregation, the invention has the characteristics of about 4V of discharge voltage, high discharge and charge capacitance, excellent circulation stability, high safety, simple process, low cost and little influence on the environment.

Disclosed is an anode material comprising a metal core layer capable of repetitive lithium intercalation / deintercalation; an amorphous carbon layer coated on the surface of the metal core layer, and a crystalline carbon layer coated on the amorphous carbon layer. The anode material not only maintains a high charge / discharge capacity, which is an advantage of a metal-based anode material, but also inhibits changes in the volume of a metal core layer caused by repetitive lithium intercalation / deintercalation in virtue of an amorphous carbon layer and a crystalline carbon layer, thereby improving the cycle life characteristics of cells.

Disclosed is a negative electrode for a nonaqueous secondary battery comprised of a current collector and an active material structure containing an electro-conductive material having low capability of forming a lithium compound on at least one side of the current collector, the active material structure containing 5 to 80% by weight of active material particles containing a material having high capability of forming a lithium compound. The active material structure preferably has an active material layer containing the active material particles and a surface coating layer formed on the active material layer.

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 invention discloses a graded high-nickel ternary anode material, and a preparation method and an application thereof. The graded high-nickel ternary anode material is prepared by the following method: 1) mixing a high-nickel polycrystalline precursor with anhydrous LiOH and a doping additive, performing sintering, mixing the obtained product with a coating additive, and performing sintering toobtain a high-nickel polycrystalline material; 2) mixing a ternary monocrystalline silicon precursor with a lithium source and the doping additive, performing sintering, mixing the obtained product with the coating additive, and performing sintering to obtain a ternary monocrystalline silicon material; and 3) mixing the high-nickel polycrystalline material with the ternary monocrystalline siliconmaterial, or mixing the mixed material with the coating additive, and then performing sintering. The invention further discloses an application of the graded high-nickel ternary anode material in lithium batteries. The graded material prepared by the method provided by the invention has higher compaction and cycle stability than the single polycrystalline material, has higher capacity than the single monocrystalline silicon, and the gas production and service life problems of the battery can be effectively improved after the grading modification.

A negative electrode for a non-aqueous electrolyte secondary battery in the present invention includes an active material including Si, a conductive material, and a binder. The binder is polyimide and polyacrylic acid, and the conductive material is a carbon material.

The invention discloses a silicon dioxide composite anode material for a lithium ion battery, as well as a preparation method and an application of the silicon dioxide composite anode material. The silicon dioxide composite anode material is prepared from the components of silicon dioxide powder and a conductive carbon layer with the surface of the silicon dioxide powder is uniformly and densely coated. With the adoption of the silicon dioxide composite anode material, the original component structure of an SiO material system is kept, so that the lower volume effect is ensured; the silicon dioxide dense carbon layer coating structure is successfully realized by adopting the technologies of mixing kneading, sheet rolling, press forming and the like, and thus the first coulombic efficiency of the silicon dioxide composite anode material is remarkably increased, and can reach a theoretical value being larger than 77 percent, and the cycle performance and the conductive characteristic are also remarkably improved, so that the silicon dioxide composite anode material is suitable for being charged and discharged with the large rate and can be applied to the power market.

The energy density of the entire cell may be improved while retaining high power density by use of an alkali metal transition metal polyanion compound as the cathode and a thin film metal or metalloid anode. The thin film anode may be initially unalloyed or partially unalloyed. During use, the thin film anode may be only partially unalloyed relative to the theoretical maximum. The high volumetric capacity of the metal anode makes it possible to use a dense or porous thin film anode in conjunction with a relatively thin particle-based cathode to thereby improve the energy density of the cell.

The application relates to the field of energy storage materials, and discloses a combined electrode with ultrahigh electron and ionic conductivity and a preparation method thereof. The combined electrode is formed in a manner that a battery active material is uniformly tied in a three-dimensional multi-hole network formed by carbon nano tubes which are connected in a crossing manner, and meshes and the surface of the active material are filled or coated with a solid electrolyte material. According to the combined electrode, the carbon nano tubes, which are communicated with one another, can form an ultrahigh electrical transmission network, on the one hand, a solid electrolyte can provide the ultrahigh lithium-ion transmission capacity while not influencing the connection of the carbon nano tubes and the conductive capacity of the electrode; on the other hand, the three-dimensional network formed by the carbon nano tubes is also fixed by virtue of the solid electrolyte, the formation of a solid electrolyte interface is controlled, and an active material is protected under the high charge-discharge voltage. The combined electrode has the high reversible capacity and the enhanced rate capability, and can meet the requirement of a power automobile or a mixed power automobile.

A lithium secondary battery has high capacity and excellent current characteristics. The lithium battery comprises of a positive electrode, a negative electrode and an electrolyte; the negative electrode comprising Al2O3 particles not relating to the charge-and discharge reactions of the battery. The presence of the ceramics particles in the electrode leads to a decrease in the internal resistance of the battery because of the enhancement of ion conductivity in the electrode, resulting in higher capacity at high rate discharge of the lithium secondary battery.

A polycrystalline LiFePO4 powder with olivine structure is prepared from Fe(Ac)2, FeSO4.7H2O, Ba(Ac)2 and organic acid by the sol-gel method. Its advantages are short period, low burning temp., low energy consumption, high purity and electric conductivity, and high granularity uniformity. It is suitable for making Li-ion battery.

The invention discloses a preparation method of a single-crystal-morphology lithium ion battery ternary positive material. The method comprises the following steps: (1) preparing an inflorescence-shaped ternary positive material precursor particles by clustering lamellar primary particles in a coprecipitation method, wherein the D50 of the precursor particles is 2-5micron, the BET is more than 100m<2> / g, and the valences of nickel, cobalt and manganese are +2; (2) mixing a precursor obtained by adopting the coprecipitation method with auxiliaries to obtain a mixture 1, and performing high-temperature sintering on the mixture 1 at the temperature between 600-950 DEG C so as to obtain a round-likely roundness type oxide; (3) mixing the round-likely roundness type oxide precursor obtained by the high-temperature sintering with a lithium salt so as to obtain a mixture 2, and performing sintering on the mixture 2 at the temperature between 700-1000 DEG C so as to obtain a product; and (4) dispersing the product obtained by sintering in the step (3), and performing heating treatment on the dispersed product at the temperature between 780-1000 DEG C so as to obtain the single-crystal-morphology lithium ion battery ternary positive material. The prepared positive material is made from the uniform single-crystal primary particles with good dispersibility, and the problem that the primary particles are easy to cluster in the high-temperature sintering process in a conventional method can be effectively overcome.

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 preparation method of a nano Ni3S2 material and belongs to the field of novel energy resources and electrochemistry. The preparation method of the nano Ni3S2 material is characterized by synthesizing the nano Ni3S2 material by taking a Ni net with a three-dimensional porous structure by virtue of a solvothermal method. A nano Ni3S2 active substance formed during the solvothermal process is directly loaded on an upper matrix of the Ni net, so that the active substance Ni3S2 is in relatively firm contact with a Ni net of a current collector; gaps of the porous Ni net can effectively buffer the volume change of the Ni3S2 in the processes of removing and embedding lithium, so that the cycle stability of the composite material can be improved; meanwhile, by virtue of a three-dimensional conductive network of the Ni net, the electronic conductivity of the composite material can be improved, so that the rate performance of the material is improved. The preparation method of the nano Ni3S2 material is simple, green, free from pollution, low in cost and suitable for industrial production. The Ni3S2 material prepared by adopting the method is small in particle size and uniform in particle distribution; according to an electrode prepared from the material, a polymer adhesive and a conductive agent do not need to be added in the electrode; the electrode has the high electrochemical performance and can be widely used in the fields of various portable electronic devices, electric automobiles, aeronautics and astronautics, and the like.

Novel proton exchange membrane fuel cells and direct methanol fuel cells with nanostructured components are configured with higher precious metal utilization rate at the electrodes, higher power density, and lower cost. To form a catalyst, platinum or platinum-ruthenium nanoparticles are deposited onto carbon-based materials, for example, single-walled, dual-walled, multi-walled and cup-stacked carbon nanotubes. The deposition process includes an ethylene glycol reduction method. Aligned arrays of these carbon nanomaterials are prepared by filtering the nanomaterials with ethanol. A membrane electrode assembly is formed by sandwiching the catalyst between a proton exchange membrane and a diffusion layer that form a first electrode. The second electrode may be formed using a conventional catalyst. The several layers of the MEA are hot pressed to form an integrated unit. Proton exchange membrane fuel cells and direct methanol fuel cells are developed by stacking the membrane electrode assemblies in a conventional manner.