期刊
CHEMISTRY OF MATERIALS
卷 30, 期 15, 页码 5362-5372出版社
AMER CHEMICAL SOC
DOI: 10.1021/acs.chemmater.8b02182
关键词
-
资金
- Hong Kong University of Science and Technology
- Hong Kong Polytechnic University
- Hong Kong Research Grants Council [611213]
- Hong Kong Polytechnic University [1-ZE30]
- DOE Office of Science [DE-AC02-06CH11357]
- French National Research Agency (ANR) as part of the Investissements d'Avenir program [ANR10-EQPX45]
In the quest for high energy density rechargeable batteries, conversion-type cathode materials stand out with their appealing multielectron transfer properties. However, they undergo a series of complex phase transitions upon initial cycling as opposed to conventional intercalation-type materials. Within this category, iron-based mixed-anion solid solutions (FeOxF2-x) have captured the most attention of the battery community, owing to their high theoretical capacity and moderate cyclability. In the meantime, it was recently demonstrated, via a series of electrochemical cycling experiments, the in situ preparation of manganese-based mixed-anion cathode materials based on decomposition of electrolyte salt LiPF6 in the presence of MnO. To take a step forward, we herein report a routine protocol to prepare 220 mAh g(-1)-class composite cathodes. In addition, we provide a comprehensive understanding of the in situ fluorination and locally reversible phase transitions using complementary analytical techniques. The charged phase, with an average Mn oxidation state of ca. +2.8, consists of a highly disordered O-rich cubic-spinel-like core and an F-rich amorphous shell. Upon discharge, lithiation induces further phase transition, forming LiF, MnO, and a lithiated rocksalt-like phase. This work, which we also extended to the iron-based system, offers insights into modification of chemical and electronic properties of electrode materials by in situ fluorination.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据