9677 results about "Cyclic stability" patented technology

A process for producing solid nanocomposite particles for lithium metal or lithium ion battery electrode applications is provided. In one preferred embodiment, the process comprises: (A) Preparing an electrode active material in a form of fine particles, rods, wires, fibers, or tubes with a dimension smaller than 1 μm; (B) Preparing separated or isolated nano graphene platelets with a thickness less than 50 nm; (C) Dispersing the nano graphene platelets and the electrode active material in a precursor fluid medium to form a suspension wherein the fluid medium contains a precursor matrix material dispersed or dissolved therein; and (D) Converting the suspension to the solid nanocomposite particles, wherein the precursor matrix material is converted into a protective matrix material reinforced by the nano graphene platelets and the electrode active material is substantially dispersed in the protective matrix material. For a lithium ion battery anode application, the matrix material is preferably amorphous carbon, polymeric carbon, or meso-phase carbon. Such solid nanocomposite particles provide a high anode capacity and good cycling stability. For a cathode application, the resulting lithium metal or lithium ion battery exhibits an exceptionally high cycle life.

The present invention relates to graphite alkene iron lithium phosphate positive active material, a preparing method thereof, and a lithium ion twice battery based on the graphite alkene modified iron lithium phosphate positive active material. Graphite alkene and iron lithium phosphate are dispersed into water solution to be mixed evenly by stirring and ultra audible sound, then, are dried to obtain iron lithium phosphate material compounded by the graphite alkene and the iron lithium phosphate to be annealed by high temperature, and finally, the graphite alkene modified iron lithium phosphate positive active material is obtained. Compared with traditional carbon coated and conductive polymeric adulteration modified lithium batteries, the lithium ion twice battery based on the graphite alkene modified iron lithium phosphate positive active material has the advantages of high battery capacity, good charging-discharging circulating performance, long life and high circulating stability, and has great utility value.

The disclosed composite carbon material of negative pole in lithium ion cell is composite graphite including spherical graphite and covering layer, which is pyrolytic carbon of organic matter. Inserted transition metal elements are contained between layers of graphite crystal. Preparation method is as following: crushing graphite, shaping and sphericized, purifying treatment, washing, dewatering and drying, dipped in salt solution doped by transition metal in multivalence, mixed with organic matter, covering treatment, and carbonizing treatment or graphitization treatment. Comparing with prior art, the disclosed material of negative pole possesses advantages of fine capability of embedding lithium and taking off lithium, high cyclical stability, reversible specific capacity larger than 350mAh / g, coulomb efficiency higher than 94% at first cycle, conservation rate for capacity larger than 80% in 500 times of circulation.