Journal of Lanzhou University of Technology ›› 2023, Vol. 49 ›› Issue (5): 10-19.

• Materials Science and Engineering • Previous Articles     Next Articles

Kinetic behavior of lithium storage in ferric phosphide doped sulfide polyacrylonitrile

LIU Wen-wu1,2, XU Zhi-qiang1,2, LEI Yi-xiao1,2, ZHENG Ya-wen1,2, DA Shi-ji1,2, WU You-zhi1,2   

  1. 1. School of Materials Science and Engineering, Lanzhou Univ. of Tech., Lanzhou 730050, China;
    2. State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals, Lanzhou Univ. of Tech., Lanzhou 730050, China
  • Received:2023-04-06 Online:2023-10-28 Published:2023-11-07

Abstract: Fe-phosphide doped sulfide polyacrylonitrile (FeP@SPAN) was synthesized by high-temperature phosphating. The P—S chemical coordination constructed in FeP@SPAN enhances the compatibility between the HOMO level of the nucleophile S2- and the LUMO level of the electrophilic reagent Li+ during the discharge process, reduces the bonding orbital σ level of the reduction product Li2S, and speeds up the kinetic behavior of lithium storage reaction in the positive electrode. The phase structure, electrochemical properties, and effects of FeP@SPAN cathode material on redox kinetics during battery operation were investigated. The results showed that FeP is connected with SPAN through the P—S bond, and the influence of FeP on the morphology of SPAN can be ignored. FeP@SPAN, as the positive electrode of the battery, effectively improves the conductivity of the battery, reduces the impedance of the positive electrode, alleviates the dissolution of polysulfide, and improves the redox kinetics. Compared with the initial SPAN positive electrode, the FeP@SPAN positive battery has an initial capacity of 1 285.8 mAh/g at A current density of 0.2 A/g, and can still maintain the capacity of 615.2 mAh/g after 500 cycles at1 A/g current density with the average capacity attenuation per cycle of 0.079%.

Key words: FeP, Lithium-organic sulfur battery, electrochemical performance

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