A kind of mixed transition metal borate negative electrode material and preparation method thereof

Abstract

The invention discloses a mixed transition metal borate negative electrode material and a preparation method thereof. Mixed transition metal borate comprises two transition metal elements, namely ironand vanadium, and has a chemical formula of FeVBO4 or FeVBO4 / C, wherein the FeVBO4 belongs to a monoclinal system; and cell parameters are as follows: a is equal to 9.4-9.9angstrom, b is equal to 3.0-3.5angstrom, c is 9.1-9.6angstrom, beta is equal to 90-93 degrees and Z is equal to 4. The preparation method comprises the following steps of taking a vanadium salt or vanadium oxide, an iron salt or iron oxide, boric acid or boron oxide or borate and citric acid or glucose or other organic carbon materials as raw materials; mixing by using a sol-gel method; carrying out presintering and curing;and finally sintering to obtain the mixed transition metal borate negative electrode material. The mixed transition metal borate is used as a negative electrode material for a lithium-ion battery, the discharge voltage plateau to lithium is about 0.6V (vs. Li), formation of lithium dendrites can be effectively avoided and the safety performance of the lithium-ion battery is improved.

Description

technical field [0001] The invention belongs to the field of lithium ion battery electrode materials, and in particular relates to a mixed transition metal borate negative electrode material and a preparation method thereof. Background technique [0002] With the development of smart mobile devices, electric vehicles, and clean energy, the demand for advanced energy storage batteries with high specific energy, good safety, and long cycle life is becoming increasingly urgent. Although new battery systems such as lithium-air batteries, lithium-sulfur batteries, aluminum-ion batteries, and magnesium-ion batteries have made great progress in the experimental stage, commercialization still faces many insurmountable problems. Today, lithium-ion batteries are still the mainstream product and the best choice in the energy storage battery market, and have been successfully and widely applied to various portable electronic products (such as smartphones, tablet computers, notebook comp...

AI Technical Summary

Problems solved by technology

[0003] Carbon materials such as hard carbon graphite are a common type of anode materials for lithium-ion batteries, but their theoretical and actual specific capacity is low (~300 mAh / g), and their compaction density is small, resulting in low overall energy density of the anode.

In addition, the lithium intercalation voltage of graphite-based anode materials is very low (<0.1V), and it is prone to lithium precipitation to form dendrites, which may pierce the separator and cause internal short circuit; at the same time, its solid-electrolyte interface film (SEI) has poor thermal stability. , when the battery overheats, it will further decompose and generate heat

Although the transition metal oxide-type negative electrode material has a high specific capacity, its redox potential to lithium metal is high (>1V), which greatly reduces the output voltage of the full battery.

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