60results about How to "Limit volume expansion" patented technology

The invention discloses a SiOC ceramic material used for preparing the cathode of a lithium ion battery, a preparation method thereof and a lithium ion battery prepared from the ceramic material. The SiOC ceramic material comprises silicon, oxygen and carbon, and the mol ratio of silicon to oxygen to carbon is 1: alpha: beta, wherein, alpha is 0.4 to 0.2, beta is 0.4 to 5.0, and alpha plus beta is 0.8 to 7.0. The preparation method comprises the following steps: preparing organosilicon polymers with a molecular formula of a(R1R2SiO)x(R3R4SiO2)y(R5R6SiO3)zb, wherein, a and b are terminated functional groups, R1, R2, R3, R4, R5 and R6 are functional groups, at least one of which is hydrogen groups or alkenyl groups, x is 0.3 to 1, y is 0 to 0.7, z is 0 to 0.5, and x plus y plus z is 1; preparing organic small molecular compounds which comprise active groups that can react with hydrogen groups, silanol groups or alkenyl groups; mixing the organosilicon polymers with the organic small molecular compounds, preparing the two into a copolymer through crossing and curing, and carrying out pyrolysis so as to obtain the SiOC ceramic material. The lithium ion battery provided in the invention has the characteristics of high capacity, good cycle performance and high reversible capacity.

The invention relates to a preparation method of a silicon-based negative electrode material based on a polyamic acid-based electrode binder, belongs to the technical field of secondary batteries, andsolves the technical problem that a binder is used for preparing a silicon negative electrode of a secondary battery. The preparation method comprises the following steps: first, adding the organic silicon modified polyamic acid copolymer binder, a silicon-containing active material and a conductive auxiliary agent into a solvent according to a mass ratio of 5-20: 60-80: 5-20, and uniformly stirring at room temperature for 30 min -12 h to prepare pasty slurry; then, coating a current collector with the prepared slurry; and finally, drying the current collector coated with the slurry at the drying temperature of 60-80 DEG C, and after drying is completed, manufacturingthe silicon-based negative electrode through stamping forming. The preparation method is low in cost and easy to operate, can effectively maintain the structural stability of the active material, and has relatively high cyclic specific capacity and cyclic stability.