Amorphous Metal Polysulfides: Electrode Materials with Unique Insertion/Extraction Reactions

作者：Sakuda Atsushi^*; Ohara Koji; Fukuda Katsutoshi; Nakanishi Koji; Kawaguchi Tomoya; Arai Hajime; Uchimoto Yoshiharu; Ohta Toshiaki; Matsubara Eiichiro; Ogumi Zempachi; Okumura Toyoki; Kobayashi Hironori; Kageyama Hiroyuki; Shikano Masahiro; Sakaebe Hikari; Takeuchi Tomonari^*

来源：Journal of the American Chemical Society, 2017, 139(26): 8796-8799.

DOI：10.1021/jacs.7b03909

A unique charge/discharge mechanism of amorphous TiS4 is reported. Amorphous transition metal polysulfide electrodes exhibit anomalous charge/discharge performance and should have a unique charge/discharge mechanism: neither the typical intercalation/deintercalalion mechanism nor the conversion-type one, but a mixture of the two. Analyzing the mechanism of such electrodes has been a challenge because fewer tools are available to examine the "amorphous" structure. It is revealed that the electrode undergoes two distinct structural changes: (i) the deformation and formation of S-S disulfide bonds and (ii) changes in the coordination number of titanium. These structural changes proceed continuously and concertedly for Li insertion/extraction. The results of this study provide a novel and unique model of amorphous electrode materials with significantly larger capacities.

• 出版日期2017-7-5