Method for preparing lithium-sulfur battery composite positive electrode material by electrostatic spinning method and application of lithium-sulfur battery composite positive electrode material

Abstract

The invention discloses a method for preparing a lithium-sulfur battery composite positive electrode material by an electrostatic spinning method and application of the lithium-sulfur battery composite positive electrode material. The method comprises the steps of 1) synthesizing a PAN / PS / acetylacetone manganese nanofiber used as a precursor by an electrostatic spinning technology; and 2) obtaining a MnO nanoparticle composite nitrogen-doped porous carbon nanofiber composite material by the pre-oxidization and subsequent high-temperature carbonization process according to the characteristics of high-temperature decomposition of PS. The composite material is simple in preparation process and low in cost, is easy to process and can be used for production on a large scale. The nitrogen-dopedcarbon fiber framework of the material has a stable three-dimensional space structure, the conduction of lithium ion and electron is facilitated, and the conductivity of the sulfur composite positiveelectrode is improved; and meanwhile, MnO particles are grown in the nitrogen-doped porous carbon fibers in an in-situ way by the electrostatic spinning method, enough storage space is provided for elemental sulfur, lithium polysulfide can be effectively absorbed, and the shuttle effect of the lithium-sulfur battery is prevented.

Description

technical field [0001] The invention relates to the field of electrochemical energy storage, in particular to a method and application of an electrospinning method for preparing a lithium-sulfur battery composite cathode material. Background technique [0002] Among all kinds of new secondary batteries, lithium-sulfur batteries have high theoretical specific capacity (1675mA h g -1 ), high specific energy density (2600Wh kg -1 ) and high volume specific energy density (2199W h L -1 ) advantages, it is considered to have great application prospects in high energy density energy storage systems (such as electric vehicles). In addition to appealing advantages, lithium-sulfur batteries are considered to be the development direction of the next-generation high-energy-density secondary battery system due to their abundant reserves, environmental friendliness, and low price, and have attracted extensive attention from new energy researchers. At the same time, lithium-sulfur batt...

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Problems solved by technology

At the same time, lithium-sulfur batteries are also facing some problems: simple substance S and the poor conductivity of the final discharge product lead to low utilization of active materials and low specific capacity; II) the intermediate discharge product Li 2 S x (4

Combining the sulfur cathode with a highly conductive material to improve conductivity and combining the sulfur cathode with a polar oxide to inhibit the dissolution of polysulfides can solve the problems of the lithium-sulfur battery itself and improve the electrochemical performance of the lithium-sulfur battery. However, how to improve the conductivity of the sulfur cathode and at the same time suppress the dissolution of polysulfides is still a difficult problem.

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