149results about How to "Reduce expansion" patented technology

The invention discloses a heat-insulating ceramic fiber board and a preparation method thereof. The heat-insulating ceramic fiber board comprises the following raw materials in parts by mass: 96-114 parts of aluminum silicate fiber mixed cotton, 4-6 parts of zirconium oxide fiber, 9-12 parts of alkaline silica sol, 12-15 parts of a water-based resin dispersant, 8-10 parts of aluminum oxide fine powder and 5-8 parts of high-temperature ceramsite sand. Wherein the aluminum silicate fiber mixed cotton is a mixture composed of aluminum silicate fiber raw cotton, aluminum silicate fiber broken cotton and aluminum silicate short fibers. The heat insulation ceramic fiber board is high in strength, long in service life, low in heat conductivity coefficient and good in heat insulation performance.

The invention discloses a nanometer silicon filled microcrystalline graphite negative electrode material and a preparation method and application thereof. The preparation method of the nano-silicon filled microcrystalline graphite negative electrode material comprises the following steps: by taking microcrystalline graphite as a base material, depositing silane between sheet layers of the microcrystalline graphite by adopting a gradient heating method to obtain a nano-silicon filled microcrystalline graphite composite material; and finally, forming the nano-silicon filled microcrystalline graphite negative electrode material with a porous structure on the surface of the nano-silicon filled microcrystalline graphite composite material through carbon source coating carbonization. According to the nano-silicon-filled microcrystalline graphite negative electrode material with the core-shell structure provided by the invention, an inner core is a silicon-graphite composite material formed by nano-silicon-filled microcrystalline graphite, nano-silicon particles are filled in the surfaces and gaps of crystalline grains of the microcrystalline graphite, volume expansion of the nano-silicon in the charging and discharging process is inhibited by a microcrystalline graphite matrix material, and particularly, the volume expansion of the nano-silicon in the charging and discharging process is inhibited by the microcrystalline graphite matrix material. And due to different structural orientations of the microcrystalline graphite, the stress effect can be counteracted, and the volume expansion of the material is further inhibited.

The invention relates to the technical field of electrode materials, in particular to porous carbon, a silicon-carbon negative electrode material, an electrode plate, a lithium ion battery and an electric appliance. The porous carbon has micropores and mesopores, and the percentage of the pore volume of pores with the pore diameter smaller than 3 nm in the total pore volume is higher than 85%; the percentage of the pore volume of pores with the pore diameter less than 0.7 nm in the total pore volume is less than 15%; the pore size distribution of the porous carbon is in a Koelreuteria-type distribution, and the Koelreuteria-type distribution is that Dv / Dw of a pore size distribution curve is greater than 0.05 cm < 3 >. G <-1 >. Nm <-1 > in a pore size interval of 1-3nm. The porous carbon provided by the invention is micro-mesoporous porous carbon, is distributed in a koelreuteria shape, is low in pore resistance, can improve the silicon loading efficiency, ensures the adsorption capacity and also ensures the de-intercalation of lithium ions, and the silicon-carbon negative electrode material prepared from the porous carbon is high in capacity and efficiency and lower in expansion performance.

The invention relates to the technical field of lithium batteries, and discloses a silicon-based composite negative electrode material and a preparation method thereof, a lithium ion battery negative electrode plate and a lithium ion battery. The negative electrode material comprises a matrix, a carbon layer coated on the outer surface of the matrix and a graphene oxide sheet layer coated outside the carbon layer, the substrate is a silicon oxide SiOx, and 0 lt; xlt; 2; the weight ratio of the matrix to the carbon layer to the graphene oxide sheet layer is 1: (0.1-0.2): (0.2-0.3). The silicon oxide SiOx is coated on the substrate by the carbon layer, so that the direct contact between the substrate and an electrolyte can be reduced, the probability of side reaction can be reduced, the formation of a stable SEI interface and a graphene oxide sheet layer is facilitated, and the conductivity and cycling stability of the silicon-based composite negative electrode material can be improved; meanwhile, the lithium ion battery containing the silicon-based composite negative electrode material has a relatively low expansion rate, and the first-cycle coulombic efficiency and the cycle stability of the battery can be effectively improved.

The invention discloses a porous carbon microsphere material, a silicon-carbon composite material and a preparation method and application thereof, and the preparation method of the porous carbon microsphere material comprises the following steps: S1, mixing a polymer, a solvent and conductive carbon black to obtain a precursor solution; s2, preparing the precursor solution into a carbon microsphere precursor material by adopting an electrostatic spraying method; s3, sequentially carrying out pre-oxidation and heat treatment on the carbon microsphere precursor material to obtain a spherical carbon material; s4, performing supercritical hydrothermal activation on the spherical carbon material, and performing post-treatment to obtain a porous carbon microsphere material; the activation temperature is 300 to 600 DEG C; the activation pressure is 15 to 30 MPa; the activation time is 0.5 to 1 hour. The porous carbon microspheres prepared by the invention have a series of adjustable physical and chemical characteristics, highly developed pore structures, high mesoporosity and better mechanical strength, and can enable lithium ion batteries to have the characteristics of low pole piece expansion rate, high first coulombic efficiency, excellent cycling stability and the like when being further applied to the lithium ion batteries.