Open AccessUnraveling the Conversion Evolution on Solid‐State Na–SeS 2 Battery via In Situ TEM
Author(s) -
Zhang Ziqi,
Wang Zaifa,
Zhang Long,
Liu Di,
Yu Chuang,
Yan Xinlin,
Xie Jia,
Huang Jianyu
Publication year - 2022
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.202200744
Subject(s) - chemical engineering , electrochemistry , materials science , in situ , battery (electricity) , electrolyte , transmission electron microscopy , amorphous solid , energy storage , electrode , nanotechnology , chemistry , crystallography , thermodynamics , organic chemistry , engineering , power (physics) , physics
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–SeS 2 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–Se x S y intermediate phase appears during the direct conversion from SeS 2 to Na 2 S, 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 SeS 2 batteries using a Na 3 SbS 4 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.