Preparation method of carbon-coated nano-boron-lithium composite material for lithium-sulfur battery negative electrode

Abstract

The invention relates to a lithium ion battery technology, and aims to provide a preparation method of a carbon-coated nanometer boron-lithium composite material for a lithium-sulfur battery cathode. The preparation method comprises the steps of adding glucose, urea and lithium metaborate into deionized water, and carrying out supersonic vibration for mixing and dissolving; spray drying a solution, and curing for 6 hours at the temperature of 106 DEG C to form a precursor; warming to 500 DEG C under the protection of a nitrogen environment, carbonizing for 2 hours at constant temperature, and heating for 2 to 10 hours at the temperature of 900 to 1300 DEG C to obtain the carbon-coated nanometer boron-lithium composite material. According to a lithium-sulfur battery formed by adopting the carbon-coated nanometer boron-lithium composite material as a cathode material provided by the invention, a battery cell can be produced in dried air, so that the safety, the reliability and the production efficiency in producing the lithium-sulfur battery are greatly improved, and the equipment cost and the production cost are reduced. The charging / discharging cycling stability of a boron-lithium electrode can be greatly improved, and the high-rate charge-discharge cycle life of a lithium-sulfur ion battery is prolonged.

Description

technical field [0001] The invention relates to a lithium-ion battery technology, more specifically, the invention relates to a preparation method of a carbon-coated nano-boron-lithium composite material used for a negative electrode of a lithium-sulfur battery. Background technique [0002] Lithium-ion batteries have the advantages of light weight, large capacity, and no memory effect, so they have been widely used. Many digital devices now use lithium-ion batteries as power sources. The energy density of lithium-ion batteries is very high, its capacity is 1.5 to 2 times that of nickel-metal hydride batteries of the same weight, and its advantages such as low self-discharge rate and no toxic substances are important reasons for its wide application. In 1990, Nagoura and others in Japan developed a negative electrode using petroleum coke and LiCoO 2 Lithium-ion battery as the positive electrode: LiC 6 |LiClO 4 -PC+EC|LiCoO 2 . same year. The two major battery companie...

AI Technical Summary

Problems solved by technology

At present, the biggest problem of lithium-sulfur batteries is that lithium polysulfide dissolved in the electrolyte is formed during charging and discharging, and the dissolved lithium polysulfide reacts with lithium metal in the negative electrode, causing capacity loss, which leads to a rapid decline in the capacity of lithium-sulfur batteries, showing extreme poor cycle life

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