Unraveling the Conversion Evolution on Solid‐State Na–SeS2 Battery via In Situ TEM

Advanced Science

Ziqi Zhang¹  Jianyu Huang¹  Long Zhang¹  Di Liu¹  Zaifa Wang¹  Xinlin Yan²  Jia Xie³  Chuang Yu³ 

[1] Clean Nano Energy Center State Key Laboratory of Metastable Materials Science and Technology Yanshan University Qinhuangdao Hebei 066004 China;Institute of Solid State Physics Vienna University of Technology Vienna 1040 Austria;State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan 430074 P. R. China;

关键词: composite cathode;    in situ TEM;    Na–S battery;    Se doping;    solid‐state batteries;   

DOI  :  10.1002/advs.202200744

来源: DOAJ

【 摘 要 】

Abstract All‐solid‐state (ASS) Na–S batteries are promising for a large‐scale energy‐storage system owing to numerous merits. However, the high conversion reaction barrier impedes their practical application. In this work, the basic mechanism on how Se catalyzes the conversion reaction in the Na–S batteries is unraveled. The sodiation/desodiation of Na–SeS2 nanobatteries are systematically evaluated via in situ transmission electron microscopy (in situ TEM) with a microheating device. The real‐time analyses reveal an amorphous Na–SexSy intermediate phase appears during the direct conversion from SeS2 to Na2S, and a reverse reaction succeeds at 100 °C with a prior formation of Se. The absence of polysulfides and a much lower desodiation temperature in contrast to Na–S nanobatteries demonstrate that the Se incorporation significantly lowers the conversion reaction barrier. According to these findings, the ASS SeS2 batteries using a Na3SbS4 solid electrolyte (SE) are assembled using various SE:C ratios in the composite cathodes to investigate the effect of the ion and electron transport on the electrochemical properties, including the effective transport properties, MacMullin number, and the tortuosity factor. The obtained results in turn confirm the findings from the in situ TEM. These findings are applicable to optimize other S‐based active materials and improve their utilization.

【 授权许可】

Unknown