Preparation and application of positive electrode-interlayer integrated membrane electrode material for lithium-sulfur battery

Abstract

The invention discloses preparation and application of a positive electrode-interlayer integrated membrane electrode material for a lithium-sulfur battery. According to the integrated membrane material provided by the invention, a polyacrylonitrile / carbon nanotube composite membrane solution is subjected to solvent phase conversion and carbonization to form a carbon membrane, and then the surfaceof the carbon membrane is coated with an organic membrane solution to prepare the integrated membrane electrode material of which the surface of a porous carbon membrane is covered with an organic membrane. The integrated membrane material has double functions of a positive electrode and an interlayer, and is beneficial to ion transfer. The organic membrane has a battery diaphragm function, and the carbon membrane can be used as a lithium-sulfur battery positive electrode by loading sulfur; nano-particles can be added into the carbon film to adsorb polysulfide, so that the shuttle effect of the lithium-sulfur battery is relieved, and the cycling stability, the rate capability and the coulombic efficiency of the battery are improved. The lithium-sulfur battery prepared from the integrated membrane electrode material has excellent energy storage performance, the specific capacity is 890mA hg<-1> after circulation for 100 circles under 0.2 C current density, the capacity loss rate of eachcircle is 0.21%, and the coulombic efficiency is close to 100%.

Description

technical field [0001] The invention relates to the field of positive electrode materials and interlayers of lithium-sulfur batteries, in particular to a preparation method and application of a polyacrylonitrile / carbon nanotube composite material as a positive electrode-interlayer integrated membrane material of lithium-sulfur batteries. Background technique [0002] With the rapid development of the global economy and the increasing demand for energy, the large-scale exploitation and application of fossil fuels will not only lead to the rapid depletion of the earth's resources, but also produce a large number of environmental pollutants. The electrical energy output by renewable clean energy such as solar energy and wind energy is discontinuous and unstable, so that such clean energy cannot be fully utilized. The development of high-capacity energy storage devices to store discontinuous and unstable electric energy for reuse is an effective way to solve this problem. In ad...

AI Technical Summary

Problems solved by technology

The shuttle effect of polysulfides will cause the loss of electrolyte, the loss of active materials, and accelerate the growth of lithium dendrites in the negative electrode, which will cause the battery to self-discharge, reduce the Coulombic efficiency, shorten the cycle life, and reduce the safety performance.

For the modification of lithium-sulfur battery cathode materials, adding an intermediate spacer is an effective method to alleviate the shuttle effect of lithium-sulfur batteries. Current research focuses on the improvement and optimization of a single factor, and the effect is limited.

However, the simultaneous use of multiple improvement methods will increase the complexity of the battery structure and increase the difficulty of operation

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