Atomistic Conversion Reaction Mechanism of WO3 in Secondary Ion Batteries of Li, Na, and Ca
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- 作者：Yang He ; Meng Gu ; Haiyan Xiao ; Langli Luo ; Yuyan Shao ; Fei Gao ; Yingge Du ; Scott X. Mao and Chongmin Wang
- 刊名：Angewandte Chemie International Edition
- 出版年：2016
- 出版时间：May 17, 2016
- 年：2016
- 卷：55
- 期：21
- 页码：6244-6247
- 全文大小：2658K
- ISSN：1521-3773
文摘
Intercalation and conversion are two fundamental chemical processes for battery materials in response to ion insertion. The interplay between these two chemical processes has never been directly seen and understood at atomic scale. Here, using in situ HRTEM, we captured the atomistic conversion reaction processes during Li, Na, Ca insertion into a WO3 single crystal model electrode. An intercalation step prior to conversion is explicitly revealed at atomic scale for the first time for Li, Na, Ca. Nanoscale diffraction and ab initio molecular dynamic simulations revealed that after intercalation, the inserted ion–oxygen bond formation destabilizes the transition-metal framework which gradually shrinks, distorts and finally collapses to an amorphous W and MxO (M=Li, Na, Ca) composite structure. This study provides a full atomistic picture of the transition from intercalation to conversion, which is of essential importance for both secondary ion batteries and electrochromic devices.