5results about How to "Improve initial Coulombic efficiency" patented technology

This invention relates to the field of battery technology, specifically to a composite negative electrode current collector, its preparation method, and its application. The composite negative electrode current collector of this invention includes a polymer material layer, a lithium replenishment layer, and a conductive metal layer. The lithium replenishment layer is located on at least one surface of the polymer material layer, and the conductive metal layer is located on the surface of the lithium replenishment layer away from the polymer material layer. The lithium replenishment layer includes a composite lithium material comprising a lithium metal core and a lithium compound coating layer covering the surface of the lithium metal core. The conductive metal layer has multiple through-hole structures. The composite negative electrode current collector of this invention, through the coordination of its various layer structures, is beneficial for improving the storage performance of the negative electrode, reducing battery impedance, shortening the electrolyte wetting time, enhancing lithium replenishment capacity, preventing the formation of lithium dendrites, and improving battery safety performance.

The invention belongs to the technical field of sodium ion battery negative electrode materials, and discloses a soy sauce residue-based hard carbon negative electrode material, a preparation method and an application of the soy sauce residue-based hard carbon negative electrode material in a sodium ion battery. The method comprises the steps of pre-oxidation, inorganic acid washing, organic solvent cleaning and high-temperature carbonization, the core technology idea of pre-oxidation driven synergistic purification is initiated, the core technology idea is organically combined with the subsequent high-temperature carbonization process, the pretreatment bottleneck of industrialization of preparation of hard carbon from soy sauce residues is overcome, and the method is suitable for industrial production. The high-grease soy sauce residues are efficiently and economically purified through pre-oxidation, and a primary barrier is cleared for preparing hard carbon by utilizing the soy sauce residues on a large scale; the precise reconstruction of the microstructure of the hard carbon material is synchronously realized, and the obtained hard carbon material has high reversible specific capacity and good initial coulombic efficiency; a high-performance product can be obtained at a relatively low carbonization temperature due to the pure precursor, so that the energy consumption and the production cost are reduced. The invention provides a scheme for preparing the sodium ion battery hard carbon negative electrode with low cost and high performance.

The present application provides a carbon material, a preparation method therefor and the use thereof, a negative electrode plate, a secondary battery, and a power consuming device. The carbon material comprises a porous carbon substrate and an amorphous carbon layer provided on at least part of a surface of the porous carbon substrate. When the carbon material is used as a negative electrode active material, it can make full use of the abundant porous structures in the porous carbon substrate for lithium / sodium precipitation or lithium / sodium intercalation and avoid the side reactions due to the contact between the abundant active sites on the surface of the porous carbon substrate and an electrolyte solution, such that the initial coulombic efficiency and the actual capacity of a secondary battery can be improved.

This invention relates to the field of sodium-ion battery technology, specifically to a modified hard carbon material and its preparation method, a negative electrode sheet, and a sodium-ion battery. The modified hard carbon material is obtained by mixing and grinding a hard carbon precursor with naphthalene at a mass ratio of 5-9:1-5, followed by a two-stage heat treatment. This invention utilizes the gas-phase infiltration and high-temperature carbonization of naphthalene at specific temperatures. In the first stage, naphthalene is converted into gaseous molecules. Its small kinetic diameter allows it to penetrate deep into the micropores of the hard carbon precursor and be adsorbed under capillary action and pressure difference. In the second stage, naphthalene undergoes pyrolysis, transforming in situ into an amorphous soft carbon layer. This achieves uniform and deep filling of carbon within the micropores of the hard carbon, effectively reducing the average pore size. This not only promotes the pre-desolvation of solvated sodium ions but also helps to obtain an ultrathin and stable NaF-rich solid electrolyte interface film, improving the rate performance of the material. Furthermore, this process is simple, efficient, and low-cost, which is beneficial for large-scale production.

The invention discloses an amorphous iron-based silicon-phosphorus composite negative electrode material and a preparation method and application thereof, the raw materials of the iron-based silicon-phosphorus composite negative electrode material comprise an iron element, a silicon element, a phosphorus element and a carbon material, the molar ratio of the silicon element to the phosphorus element is 2: 1-1: 2, the molar ratio of the silicon element to the iron element is 8: 1-1: 2, and the mass ratio of an iron / silicon / phosphorus mixture to the carbon material is 5: 5-8: 2; the iron-based silicon phosphorus composite negative electrode material is prepared by a one-step or multi-step mechanical ball milling method. In the iron-based silicon phosphorus composite negative electrode material, the introduction of the iron elementary substance induces the microstructure to be disordered and reduces the lithium ion diffusion energy barrier, and meanwhile, the iron elementary substance and the lithium phosphide formed in situ respectively provide abundant electron and ion transmission paths and cooperatively buffer the huge volume deformation of the silicon negative electrode in the lithiation / delithiation process; furthermore, the electrochemical reversibility, the cycling stability and the rate capability of the material in the lithium storage process are effectively improved.