A kind of preparation method and product of bio-silicon oxide

Abstract

The invention discloses a preparation method of biological silicon monoxide, which comprises the following steps: 1. cleaning rice husk to remove heavy metals, carbonizing, and decarbonizing to obtaina biological silicon dioxide coarse material; 2, crushing the biological silicon dioxide coarse material, soaking the crushed biological silicon dioxide coarse material in hydrochloric acid with theconcentration of 30-40%, soaking the soaked biological silicon dioxide coarse material in pure water for a plurality of times, and carrying out vacuum drying to obtain biological silicon dioxide; and3, deoxidizing the biological silicon dioxide by taking a mixed gas of methane and high-purity hydrogen as a reducing medium to obtain the biological silicon monoxide. The invention also discloses a product thereof. According to the invention, the problem that the existing silicon material is peeled off from the copper foil is solved, high-temperature heating caused by internal short circuit of the lithium battery is prevented, and the combustion phenomenon of the battery in a working state is avoided. The interior of the biological silicon monoxide is in a porous state, and a large number oflithium ions are absorbed, so that the gram volume ratio and the first charge-discharge efficiency of the lithium battery are improved.

Description

technical field [0001] The invention relates to the field of silicon oxide preparation, in particular to a method for preparing biological silicon oxide and a product thereof. Background technique [0002] In the application field of lithium batteries, adding silicon particles to negative electrode materials can greatly increase the capacity ratio, but silicon particles extracted from existing inorganic materials will expand by about 300% during charging and discharging of lithium batteries, resulting in powdering of silicon electrode materials And peel off from the surface of the current collector, so that the electrical contact between the active material and the current collector is lost, and a new solid electrolyte layer SEI is continuously generated. At the same time, the poor conductivity of the active material of the SEI makes the impedance of the electrode gradually decrease during the charging and discharging process. increased, which led to the deterioration of the...

AI Technical Summary

Problems solved by technology

[0002] In the field of lithium battery applications, adding silicon particles to the negative electrode material can greatly increase the capacity ratio, but the silicon particles extracted from existing inorganic materials will expand by about 300% during charging and discharging of lithium batteries, resulting in pulverization of silicon electrode materials And peel off from the surface of the current collector, so that the electrical contact between the active material and the current collector is lost, and a new solid phase electrolyte layer SEI is continuously generated. At the same time, the poor conductivity of the active material of SEI makes the impedance of the electrode gradually decrease during the charging and discharging process. increase, which leads to the deterioration of the performance of the lithium battery, resulting in a short charge and discharge cycle of the lithium battery

[0003] Therefore, in order to solve this problem in the prior art, mineral-derived silicon oxide is used as an additive. The expansion of silicon oxide during charging and discharging of lithium batteries is about half of that of pure silicon, which can relatively prolong the charging of lithium batteries. The discharge cycle, but there is still peeling, and the problem has not been completely solved

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