A preparation method of a three-dimensional current-collecting structure for lithium battery electrode materials

Abstract

The invention provides a preparation method of a three-dimensional current collecting structure for lithium battery electrode materials, belonging to the technical field of new energy materials. In the present invention, metal active particles are first adsorbed on the surface of the electrode material to form a seed layer, and then added to the prepared conductive particle solution, and nano-scale metal crystal particles are deposited and grown on the surface of the seed layer to form a three-dimensional structure electrode material, and then optimized by nano-crystal particles After forming, a three-dimensional current collecting structure for lithium battery electrode materials is obtained. The method of the invention makes the nano-scale metal crystal particles evenly and discretely attached to the surface of the electrode material, avoiding the possible agglomeration problem caused by direct mechanical mixing of conductive additives; the invention forms a three-dimensional current collecting structure inside the electrode material, so that the electrode material has more High electronic conductivity and Li+ mobility achieve low interfacial contact resistance and high conductivity, which is conducive to the application and promotion of lithium-ion batteries.

Description

technical field [0001] The invention belongs to the technical field of new energy materials, and in particular relates to a preparation method of a three-dimensional current collecting structure for lithium battery electrode materials. Background technique [0002] In recent years, as people pay more and more attention to the energy crisis and environmental issues, new energy technologies have sparked a global research boom, among which the development of new energy vehicles and new energy storage batteries and energy storage technologies has attracted much attention. Lithium-ion batteries, which have the advantages of high energy density, high working voltage, low self-discharge rate, no memory effect, and no pollution, stand out in the field of new energy technology and are recognized as the electric vehicle with the most potential for commercial development in the 21st century. Power Battery. [0003] Lithium-ion batteries are also vividly called "rocking chair batteries...

AI Technical Summary

Problems solved by technology

Most of the existing technologies directly mix electrode materials with conductive metal powder mechanically through physical contact, but the coated metal particles have a large particle size and are easy to agglomerate; or grow metal particles by chemical methods, but it is easy to cause metal doping However, the formation of invalid coating requires precious metals as raw materials, and the cost is relatively high.

[0006] In order to coat the phosphate-based positive electrode material with a surface conductive agent by adding metal conductive particles, the existing patent CN1649188A discloses a metal Ni, Cu coated LiFePO 4 The preparation method of powder, it comprises the LiFePO that prepares to have uniform particle size 4 powder, to prepare an electroless plating solution containing Ni and Cu, which will be treated with SnCl 2 , PdCl 2 Treated LiFePO 4 Put the powder into the electroless plating solution for coating to prepare metal-coated LiFePO 4 Powder, this method needs to be sensitized and activated for LiFePO 4 The powder is pre-treated, the process is complex and the precious metal palladium is used as an activator, which increases the cost; the existing patent CN103560229A discloses a method for preparing a high-conductivity lithium-ion battery lithium vanadium phosphate positive electrode material, which includes soluble phosphate, vanadium The salt is dissolved in deionized water and slowly dropped into Fehling's reagent, and then into formaldehyde solution to form a powdery precursor, which is put into a tube furnace protected by an inert or reducing gas for pretreatment and sintering to obtain a pretreatment Process the powder and sinter again to finally obtain the modified positive electrode material. This method generates Cu particles in the precursor mixed material, which easily leads to partial Cu doping in the subsequent material sintering and synthesis process.

In order to reduce the contact area between the graphite negative electrode and the electrolyte, suppress the peeling and destruction of its layered structure, increase the first-time efficiency of the negative electrode material, and improve the cycle performance of the battery, the existing patent CN104112852A discloses a preparation method of a lithium ion battery negative electrode material , it uses the metal melting method to coat a layer of metal element on the surface of the graphite negative electrode, and realizes molecular-level metal coating on the surface of the graphite negative electrode. The metal element particles prepared by this method are large and have poor uniformity

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