4results about How to "Improve lithium storage performance" patented technology

This invention provides an aluminum foil anode material for lithium-ion batteries and its preparation method. The method applies metallic aluminum to a monolithic material system. Based on a chemical displacement reaction, a rolling-heat treatment method is used to dope the target metal element into the aluminum foil composite material, achieving alloy composition design of the aluminum foil. Furthermore, carbon elements can be incorporated into the interlayer of the aluminum foil to improve the lithium storage performance of the aluminum foil anode. The preparation method of this invention is simple and feasible, with a simple process flow and low cost. It can modify a large quantity of aluminum foil in a short time, and the reaction raw materials can react completely, with useless reaction products volatilizing spontaneously. In addition, the modified aluminum foil material can be directly used as a lithium-ion battery anode material, effectively improving the lithium storage performance of the aluminum foil anode material.

This invention relates to a porous carbon material with a hierarchical distribution, its preparation method, and its application. The pores of the porous carbon material include: a first micropore (less than 10%), a second micropore (5%–15%), a first mesopore (15%–25%), a second mesopore (50%–70%), a third mesopore (1%–10%), and a fourth mesopore (less than 1%). The first micropore has a pore size of less than 1 nm; the second micropore has a pore size of greater than or equal to 1 nm but less than 2 nm; the first mesopore has a pore size of greater than or equal to 2 nm but less than 4 nm; the second mesopore has a pore size of greater than or equal to 4 nm but less than 7 nm; the third mesopore has a pore size of greater than or equal to 7 nm but less than 10 nm; and the fourth mesopore has a pore size of greater than or equal to 10 nm but less than or equal to 50 nm. The silicon-carbon composite material prepared using this porous carbon material has a high amount of nano-silicon deposition and good uniformity. Applying the silicon-carbon composite material to lithium-ion batteries can improve the battery's initial efficiency and specific capacity.

The invention discloses a binder-free transition metal sulfide composite nitrogen-doped graphene negative electrode material and a preparation method thereof, and belongs to the technical field of secondary battery negative electrode materials. According to the technical scheme, the preparation method comprises the following steps: 1) dissolving zinc nitrate, cobalt nitrate and nitrogen-doped graphene in a mixed solution of ethanol and water, uniformly mixing, adding ammonium fluoride and urea, and continuously stirring; 2) adding foamed nickel and the uniformly mixed solution into a high-pressure reaction kettle for hydrothermal treatment, cooling, washing and drying to obtain a Zn-Co-precursor; (3) calcining the Zn-Co-precursor in an inert atmosphere, and (4) adding the Zn-Co-precursor into a high-pressure reaction kettle containing a sulfur source for hydrothermal vulcanization treatment, washing and drying to obtain the ZnCo2S4-coated NGr / NF negative electrode material.The graphene negative electrode material can improve the overall performance and stability of a secondary battery.

The invention discloses a PVP (Polyvinyl Pyrrolidone) coated carbohydrate-based hard carbon negative electrode material as well as a preparation method and application thereof. The preparation method comprises the following steps: dissolving carbohydrate in water to prepare a first solution, heating the first solution for gelatinization treatment, and freeze-drying to obtain carbohydrate powder; carrying out first heat treatment on the carbohydrate powder to obtain a pre-carbonized carbon material; adding the pre-carbonized carbon material into an acid solution for reaction, and drying a reaction product to obtain carbon powder; mixing carbon powder and a doping agent, and grinding to obtain a nitrogen-sulfur co-doped precursor; adding the nitrogen-sulfur co-doped precursor into a polyvinylpyrrolidone solution to react, and then drying to obtain a coated precursor; and carrying out heat treatment on the coated precursor to obtain the polyvinylpyrrolidone coated carbohydrate-based hard carbon negative electrode material. According to the invention, the pore structure integrity and functional coating effectiveness of the carbon material are synergistically realized, the lithium storage capacity, the first coulombic efficiency and the cycle life of the lithium ion battery are improved, and the application requirements of the high-performance electrode material of the lithium ion battery are met.