Preparation And Performance Of Cathode Material For Lithium Sulfur Battery Based On Porous Carbon

Lithium-sulfur batteries are regarded as strong candidates for next-generation secondary batteries due to the extremely high energy density(1672 mAh/g),environmental friendliness,and large reserves.However,there are still problems such as insufficient response,severe shuttle effect,and poor cycle performance.Research on new and highly efficient cathode materials can effectively solve these problems and improve the performance of lithium-sulfur batteries.Based on the current research progress of lithium-sulfur batteries,we believe that the composite material composed of transition metals and their compounds and porous carbon can better improve the performance of lithium-sulfur batteries.On the one hand,transition metals and their compounds can effectively suppress the shuttle effect and improve the cycle performance.On the other hand,porous carbon can enhance the conductivity of the battery and promote the complete reaction of the positive and negative electrodes.In addition,porous carbon has a certain adsorption capacity for polysulfides.The main research works of this article are as follows:(1)A carbon-based composite material CoFe@NC/PPC was prepared and used for the performance research of cathode materials for lithium-sulfur batteries.Using pomelo peel and Prussian blue analogue as raw materials.Firstly,the Prussian blue analogue was loaded on the treated pomelo peel,and then the biomass-derived carbon material CoFe @ NC / PPC was prepared by high-temperature calcination.And through a series of characterization methods to explore the material's micro-morphology,structure and composition.Finally,a button battery was made and the battery was tested for electrical performance such as cycle and rate.The result showed good cycle stability.The initial specific capacity at low current(0.1 C,1 C=1672 mAh/g)can reach 1049.3 mAh/g;at high current(1 C),the initial specific capacity is 915.6 mAh/g,which remains at 447.4/g after 500 charge and discharge,and the Coulomb efficiency remains at 97.3%.(2)A carbon-based composite material MoSe2 / NC was prepared and used for the performance research of cathode materials for lithium selenium batteries Peptone was used as carbon source and sodium chloride as the corrosive agent,carbon-based composite material MoSe2 / NC was prepared by freeze drying and high temperature calcination.After loading the material with selenium,it was used in lithium selenium battery and showed good charge and discharge performance.The initial capacity under 0.2 C current can reach 412.1 mAh/g;the initial capacity under 1 C current is close to 309.9 mAh/g.It remains at 274 mAh/g after 200 cycles,and the Coulomb efficiency remains over 95%.The paper has 33 figures,4 tables,and 104 references.