Preparation method of zinc oxide silicon-coated anode material

Abstract

The invention relates to the technical field of lithium ion battery anode materials, especially to a preparation method of a zinc oxide silicon-coated anode material. The method comprises the following steps of in order: 1) performing ball milling processing of conductive agent graphene, a binder and silicon nanoparticles, adding deionized water, and uniformly stirring the mixture to obtain slurry; 2) coating the slurry to the surface of a current collector and then performing drying; 3) performing zinc powder activation and then performing melting processing to obtain a zinc in a molten state; and 4) after the graphene and silicon nano-particle coating porous aluminum foil negative electrode materials are uniformly coated with the zinc in the molten state, performing calcination process to obtain the zinc oxide silicon-coated anode material. The preparation process is simple and practicable, simple to operate and low in required cost, and the prepared and obtained zinc oxide silicon-coated anode material can effectively avoid the problem that the expansion and contraction of silicon in the charge-discharge reaction process, can inhibit the secondary reaction of the anode materials, can improve the stability of electrode cycle and the cycle efficiency and can have a high electrical conductivity.

Description

technical field [0001] The invention relates to the technical field of negative electrode materials for lithium ion batteries, in particular to a preparation method of zinc oxide-coated silicon negative electrode materials. Background technique [0002] Since Japan developed the first lithium-ion battery in 1990, due to its high specific capacity, high working voltage, long cycle life, and no memory effect, lithium-ion batteries have penetrated into all aspects of people's lives, and communication equipment is inseparable. Opening it, transportation equipment also shows its use, especially with the miniaturization and flexible development of electronic products, the research and development of lithium-ion batteries has attracted much attention. [0003] In order to improve the energy density of lithium-ion batteries, people are eager to find new materials with higher specific capacity to replace the traditional materials of lithium-ion batteries. Silicon is the negative elec...

AI Technical Summary

Problems solved by technology

[0003] In order to improve the energy density of lithium-ion batteries, people are eager to find new materials with higher specific capacity to replace the traditional materials of lithium-ion batteries. Silicon is the negative electrode material of lithium-ion batteries with the highest specific capacity (4200mAh / g) discovered so far. , is a negative electrode material with high potential, which can not only increase the capacity of the battery, but also reduce the load of the negative electrode material in the battery accordingly, thereby improving the energy and power density of the battery. Not only that, silicon is widely distributed in nature, Just lower than oxygen, the source is extremely abundant and the cost is low, but there are still some bottlenecks in silicon as the negative electrode material of lithium batteries. First, silicon will have the problem of volume expansion and contraction in the charge and discharge reaction, and its expansion can reach 300%. Silicon Due to volume expansion, stress is generated inside the material and the structure of the material is damaged, which leads to the fragmentation and pulverization of the material, which makes the compactness of the electrode coating material worse, and in severe cases, it will fall off. After falling off, it will be separated from the current collector. The charge-discharge reaction is difficult to continue, so the cycle stability and battery capacity of the battery are deeply affected

Images