Iron and nickel-doped activated carbon-sulfur material and preparation method and application thereof

Abstract

The invention discloses an iron and nickel-doped activated carbon-sulfur material. The iron and nickel-doped activated carbon-sulfur material is obtained by activating an inorganic nickel salt, an inorganic iron salt, activated carbon and sulfur as raw materials through a hydrothermal method, a liquid-phase in-situ composite method and a melting method. The preparation method comprises the following steps of (1) preparing iron and nickel-doped activated carbon powder through the hydrothermal method; (2) preparing an unactivated iron and nickel-doped activated carbon-sulfur material through theliquid-phase in-situ composite method; and (3) activating the iron and nickel-doped activated carbon-sulfur material. The iron and nickel-doped activated carbon-sulfur material is used as a positiveelectrode of a lithium-sulfur battery; when the current density is 167.5mA / cm<2>, the initial specific discharge capacity is 1,000-1100mAh / g; and after 100 cycles, the specific capacity is reduced to500-550mAh / g. The iron and nickel-doped activated carbon-sulfur material has the advantages that (1) the sulfur content is greatly improved; (2) dissolution of one part of polysulfide is successfullyinhibited; and (3) component distribution is uniform, negative electrode corrosion and internal resistance increase of the battery caused by the shuttle effect are effectively inhibited, and the effects of providing the specific discharge capacity, reducing the battery capacity attenuation rate and improving the cycle performance are achieved.

Description

technical field [0001] The invention belongs to the technical field of batteries, and in particular relates to an iron-nickel doped activated carbon-sulfur material and a preparation method and application thereof. Background technique [0002] With the development of society, human's demand for energy is gradually increasing. However, with the continuous and accelerated exploitation of fossil fuel resources such as coal, oil, and natural gas for nearly 200 years, the resources have gradually become exhausted. Therefore, energy issues and environmental issues have become global concerns and urgently need to be resolved. The development of secondary batteries with high energy, high density, high safety, green environmental protection and low cost is of great significance in the field of new energy. Lithium-sulfur battery is a kind of secondary battery system with higher energy density. It uses elemental sulfur or sulfur-containing materials as the positive electrode active ...

AI Technical Summary

Problems solved by technology

The material has the following problems: (1) the sulfur load of the positive electrode material is low; (2): and when the sulfur load is greater than 50%, the specific capacity is very low

The disadvantages of this material are (1): the cost of metal alkoxide in the sol-gel method is relatively high; (2): the self-propagating high-temperature synthesis method has the disadvantages that the reaction process is not easy to control, etc.

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