Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7745199 | Solid State Ionics | 2016 | 5 Pages |
Abstract
For an attempt to incorporate phosphorous ions into the Fe-containing Li2S, we have prepared Li2S-FePS3 composite positive electrode materials using the combination process of the thermal heating and the mechanical milling. The XRD results showed that the Li2S-FePS3 composite samples consisted of low-crystalline Li2S and small amounts of FeP as impurity. The electrochemical tests demonstrated that the Li2S-rich composite sample cells (Li2S:FePS3 = 4:1 mol) showed relatively high initial discharge capacity (ca. 780 mAh·gâ 1) without any pre-cycling treatments. This makes a clear contrast to the Fe-containing Li2S (Li2S-FeSx composite) sample cells, which showed the initial discharge capacity of ca. 330 mAh·gâ 1 and it was enlarged to ca. 730 mAh·gâ 1 after the stepwise pre-cycling treatment. Ex-situ XRD and XAFS measurements showed the reversible changes of the peaks ascribed to Li2S and the local structures around S atoms during cycling. The incorporation of phosphorous ions into the Fe-containing Li2S was effective for improving the structural reversibility against Li extraction/insertion reactions, resulting in the improved electrochemical performance of the cells.
Related Topics
Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
Tomonari Takeuchi, Hiroyuki Kageyama, Masahiro Ogawa, Kei Mitsuhara, Koji Nakanishi, Toshiaki Ohta, Atsushi Sakuda, Hironori Kobayashi, Hikari Sakaebe, Zempachi Ogumi,