13001results about How to "Improve electrochemical performance" patented technology

A multicell assembly is constituted by alternately stacking two types of pre-assembled elements: a bipolar electrode holding subassembly and a membrane holding subassembly. The alternate stack of elements is piled over a bottom end element and the stack is terminated by placing over the last membrane holding element a top end electrode element. Each bipolar plate electrode holding element and each ion exchange membrane separator holding element includes a substantially similar rectangular frame piece, made of an electrically nonconductive and chemically resistant material, typically of molded plastic material, having on its upper (assembly) face grooves for receiving O-ring type gasket means, and having through holes and recesses in coordinated locations disposed along two opposite sides of the rectangular frame forming, upon completion of the assembling, ducts for the separate circulation of the negative electrolyte and of the positive electrolyte through all the negative electrolyte flow chambers and all positive electrolyte flow chambers, respectively, in cascade.

The invention provides a multi-element composite nano-material for a super capacitor, and a preparation method of the nano-material. The nano-material comprises a carbon material, metal oxide and conducting polymer, and components of the nano-material can be two or more than two materials. By the aid of the characteristics such as fine electrical conductivity, long cycle life and high specific surface area of the carbon material, high pseudo-capacitance of the metal oxide and low internal resistance, low cost and high operating voltage of the conducting polymer, different types of electrode materials generate synergistic effects, advantages are mutually combined, shortcomings are mutually weakened, the energy storage characteristics of an electric double-layer capacitor and a pseudo-capacitor are simultaneously made full use of, a composite electrode material with high power density, fine circulating stability and higher energy density is prepared, and the multi-element composite nano-material is excellent in comprehensive performance when used for an electrode of the super capacitor, has the advantages of simple preparation process, short cycle, low cost and the like, and is suitable for large-scale industrial production.

The invention discloses a method for recovering and preparing lithium iron phosphate from waste lithium iron phosphate batteries. The method comprises: 1) dismantling the recovered waste lithium iron phosphate batteries, stripping battery cases, immersing the batteries, separating the electrode plates from the powder material of positive and negative terminals through a method of alternation of ultrasonic and mechanical stirring, taking out the electrode plates and diaphragms, and obtaining mixed liquor; 2) performing a preliminary ball milling to the mixed liquor, and drying the uniformly mixed slurry obtained by the preliminary ball milling; 3) calcining the dried material in oxidizing atmosphere to obtain a recovered material, adding iron source, phosphorous source and optionally new lithium iron phosphate, then adding carbon source, high energy ball milling the obtained material, drying the material to obtain a pre-burning material of the recovered material; 4) microwave sintering or solid state sintering the pre-burning material of the recovered material in protective atmosphere to obtain the product of lithium iron phosphate. The preparation method has the advantages of environmental protection, no pollution, simpleness and practicality, high production utilization rate, simple

The present application is directed to hard carbon materials. The hard carbon materials find utility in any number of electrical devices, for example, in lithium ion batteries. Methods for making the disclosed carbon materials are also disclosed.

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.

Provided is a positive electrode film of a lithium battery, comprising: (i) a positive electrode material of a lithium intercalated transition metallic oxide; (ii) a lithium ion replenisher; and (iii) a conductive agent and an adhesive. The lithium ion replenisher in the positive electrode film decomposes during initial charging and then releases lithium ions, so as to make up for a loss of lithium ions forming an SEI film on a negative electrode surface, thereby improving the reversible charging and discharging capacity of the lithium ion battery. In the prepared positive electrode film, the lithium ion replenisher can be mixed in the positive electrode material or the conductive agent in advance, and can be coated on the surface of the positive electrode of the lithium ion battery as well.

The invention relates to a method for preparing nitrogen-doped active carbon from a nitrogen-enriched biomass raw material, and belongs to the technical field of preparation of carbon materials. In the method, an active carbon material with relatively high nitrogen doping amount and a large specific surface area is prepared from the biomass raw material with rich nitrogen through carbonization and activation in an inert atmosphere. The method has the advantages as follows: the raw material is environment-friendly and renewable; the preparation process is simple; in-situ nitrogen doping can be achieved; the nitrogen doping amount and a pore structure can be controlled at the same time; a new way is provided for high-added value utilization of the nitrogen-enriched biomass raw material. The prepared nitrogen-doped active carbon can be used as an efficient electrode material, an absorbent material and a catalyst carrier and applied to the field of energy and environmental protection.

The present invention belongs to electrochemical technical field, specifically a high specific energy charging full-solid lithium air battery. The battery structure is: firstly an air diffusion layer, then an air electrode, composed of a meso-porous carbon/manganese oxide composite material, an oxygen-reduction catalyst and a macromolecule lithium electrolyte, next a multilayer aqueous vapour cover, not only serving as a electrolyte layer of the battery, but also blocking water an oxidation entering of the air, finally a metal lithium. The whole battery is sealed in the multiplayer metal/plastic, a portable sealing is on the top of the air diffusion layer which is opened when the battery is used, closed when the battery is not used. The invention adopts lithium air battery made by the meso-porous carbon / manganese oxide composite material and the room temperature ionic liquid electrolyte, the capacity achieves 800mAh/g, cycling more than 50 times. In the lithium air battery, the metal lithium has effective protection, making the Li/O2 reaction only in the electrochemical reaction, the lithium air battery not only has battery electrochemical capability, but also has excellent safety ability.

The invention belongs to the synthesis field of porous silicon materials, and particularly relates to a method for preparing porous silicon by magnesiothermic reduction. The method comprises the following steps: carrying out magnesiothermic reduction reaction based on silicon oxide SiOx (x = 0.5-2) as a raw material to generate a mixture of silicon and magnesium oxide; and then selectively dissolving away magnesium oxide with an acid so as to ultimately obtain a self-supported porous silicon material. Compared with the previous conventional electrochemical anodic etching methods, the method provided by the invention has the advantages that the use of expensive monocrystal silicon wafers is avoided, but simple, easily available and low-cost silicon oxide is used as the raw material, thereby not only reducing the cost but also increasing the yield; and the method has the advantages of simple preparation process, environmental friendliness, high preparation efficiency and good repeatability, is more suitable for industrial production, and is expected to be widely applied in the fields of lithium ion secondary batteries, optical materials, biomedical devices, gas-sensitive devices, etc.

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 provides a method for continuously synthesizing a precursor of a lithium ion battery positive material, relating to an improvement of a synthesis method of a nickle cobalt manganese termary positive material nickle cobalt lithium manganate of the lithium ion battery positive material. The method is characterized in that the synthesis process is as follows: merging a complexing agent ammonia, an aqueous solution of metal nickle cobalt manganese ions and a precipitator sodium hydroxide solution and then continuously adding the substances into a reaction kettle for a synthesis reaction under the strong stirring condition in the presence of protective gas; and aging, filtering and washing the effluent from the reaction kettle, and then drying to obtain the lithium ion battery positive material precursor spherical nickle cobalt manganese termary hydroxide. The method has the advantages that the preparation process is continuous, the particle size of the prepared nickle cobalt manganese compound hydroxide powder is controlled in a range of 5-20 microns, and the prepared nickle cobalt manganese compound hydroxide powder is even in distribution and excellent in electrochemistry property. The method has the advantages of high production efficiency, low production cost and significant economic and social benefits, and the energy is saved.