Solid-state lithium-sulfur battery enabled by Thio-LiSICON/Ploymer composite electrlyte and sulfuized polyacrylonitrile cathode

Li M, Frerichs JE, Kolek M, Sun W, Zhou D, Huang CJ, Hwang BJ, Hansen MR, Winter M, Bieker P

Zusammenfassung

Solid-state lithium-sulfur battery (SSLSB) is attractive due to its potential for providing high energy density. However, the cell chemistry of SSLSB still faces challenges such as sluggish electrochemical kinetics and prominent "chemomechanical" failure. Herein, a high-performance SSLSB is demon-strated by using the thio-LiSICON/polymer composite electrolyte in combina-tion with sulfurized polyacrylonitrile (S/PAN) cathode. Thio-LiSICON/polymer composite electrolyte, which processes high ionic conductivity and wet-tability, is fabricated to enhance the interfacial contact and the performance of lithium metal anodes. S/PAN is utilized due to its unique electrochemical characteristics: electrochemical and structural studies combined with nuclear magnetic resonance spectroscopy and electron paramagnetic resonance char-acterizations reveal the charge/discharge mechanism of S/PAN, which is the radical-mediated redox reaction within the sulfur grafted conjugated polymer framework. This characteristic of S/PAN can support alleviating the volume change in the cathode and maintaining fast redox kinetics. The assembled SSLSB full cell exhibits excellent rate performance with 1183 mAh g-1 at 0.2 C and 719 mAh g-1 at 0.5 C, respectively, and can accomplish 50 cycles at 0.1 C with the capacity retention of 588 mAh g-1. The superior performance of the SSLSB cell rationalizes the construction concept and leads to considerations for the innovative design of SSLSB.