Preparation method of lithium-sulfur battery electrode material

Abstract

The invention discloses a preparation method of a lithium-sulfur battery electrode material, which comprises the following steps: adding hexadecyltrimethylammonium bromide into absolute methanol, carrying out ultrasonic treatment, adding carbon nanotubes and cobalt nitrate hexahydrate, and carrying out ultrasonic treatment to obtain a solution A; adding 2-methylimidazole into an absolute methanolsolution, carrying out ultrasonic treatment to obtain a transparent solution B, adding the solution A into the solution B, conducting stirring, centrifuging, filtering, and drying to obtain a productI; adding the product I into an absolute ethyl alcohol solution, carrying out ultrasonic stirring, then adding nickel nitrate hexahydrate, carrying out ultrasonic treatment, and then conducting stirring, filtering and drying to obtain a product II; putting the product II into a tubular furnace, and conducting calcining for 2.5-3 hours in a nitrogen atmosphere to obtain a product NiCo(O) / CNTs; andadding NiCo(O) / CNTs into a high-pressure reaction kettle with a polytetrafluoroethylene lining, then adding sublimed sulfur, carrying out high-temperature reaction, and conducting cooling to obtain the material Ni-Co(O) / CNTs / S. The electrode material Ni-Co(O) / CNTs / S provided by the invention has excellent rate capability, and has small discharge capacity loss after 200 cycles.

Description

technical field [0001] The invention belongs to the technical field of lithium-sulfur battery electrode materials, and in particular relates to a preparation method of lithium-sulfur battery electrode materials. Background technique [0002] As a new type of electrochemical energy storage device, lithium-sulfur batteries have brought new impetus to the development of current battery technology. The theoretical energy density of lithium-sulfur batteries is 2600Wh / kg, and the theoretical specific capacity density is 1675mAh / g, which has a very good development prospect. Sulfur, the active material of lithium-sulfur batteries, has the characteristics of light weight, abundant energy storage, non-toxic, non-polluting, and environmentally friendly. As an electrode material, it is unmatched by other batteries. It is undeniable that there are still many obstacles to the application of lithium-sulfur batteries, such as poor cycle stability, low utilization of active materials, depo...

AI Technical Summary

Problems solved by technology

It is undeniable that there are still many obstacles to the application of lithium-sulfur batteries, such as poor cycle stability, low utilization of active materials, deposition of irreversible product LiS, and low Coulombic efficiency, which greatly hinder the development of lithium-sulfur batteries.

[0003] The insulation of elemental sulfur and the insulation and solubility of the intermediate product polysulfide lead to a decrease in the utilization of active materials; during the charge and discharge process, the electrode has volume expansion and generates internal stress, which leads to the destruction of the electrode structure and poor cycle stability of the battery; the charge and discharge process The LiS (4≤x≤8) generated in the system will gather on the surface of the electrode, and the passivation layer formed on the surface inhibits the transmission of lithium ions in the system, resulting in a decrease in the conductivity of the conductive network, which seriously damages the electrode / electrolyte. The interface state increases the electrode polarization; the intermediate product LiS produced during the charge and discharge process x (4≤x≤8) deposited on the electrode surface and dissolved in the electrolyte, long-chain polymers and short-chain polymers shuttle between the positive and negative electrodes to form a shuttle effect, resulting in active material loss and battery Coulombic efficiency and cycle performance Deterioration leads to faster battery performance decay

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