Unlocking Surface Sodiation Threshold of Titanium Dioxide via Coupled Electrochemical‐Thermal Activation
Abstract
ABSTRACT Titanium dioxide anodes for sodium‐ion batteries undergo an electrochemically‐induced phase transformation from crystalline to active amorphous phase in a thin surface layer, resulting in surface‐dependent capacities. The origins of this limited active layer remain unclear. Herein, we reveal that the sluggish movement of the amorphous|crystalline boundary during initial sodiation determines the thickness of the surface‐active layer. To unlock surface sodiation threshold, we propose a coupled electrochemical‐thermal activation protocol to promote the continuous movement of the amorphous|crystalline boundary during the initial cycle, thereby permanently increasing the reversible sodiation capacity. The anatase TiO 2 ‐35 nm anode delivers an enhanced capacity from 116 to 190 mAh g −1 at 0.1 A g −1 after electrochemical‐thermal activation, accompanied by its high‐rate capability and long‐term cyclability. The electrochemical‐thermal activation is also efficient for enhancing the Li + /Na + storage capacities of rutile TiO 2 anodes. This work opens a pathway for enhancing electrochemically‐induced irreversible phase transformations with enhanced charge storage performance.
Article Details
Authors (10)
Dafu Tang
State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Materials, Xiamen University, Xiamen 361005, China
Sicheng Fan
Chao Li
Zerui Yan
Yuting Song
Zhangbin Xie
State Key Laboratory of Physical Chemistry of Solid Surfaces Fujian Key Laboratory of Surface and Interface Engineering for High Performance Materials College of Materials Xiamen University Xiamen P. R. China
Weihan Lin
State Key Laboratory of Physical Chemistry of Solid Surfaces Fujian Key Laboratory of Surface and Interface Engineering for High Performance Materials College of Materials Xiamen University Xiamen P. R. China
Jiuhui Han
Tianjin Key Laboratory of Advanced Functional Porous Materials, Institute for New Energy Materials and Low-Carbon Technologies, School of Materials Science and Engineering
Dong‐Liang Peng
State Key Laboratory of Physical Chemistry of Solid Surfaces Fujian Key Laboratory of Surface and Interface Engineering for High Performance Materials College of Materials Xiamen University Xiamen P. R. China
Qiulong Wei
State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Materials, Xiamen University, Xiamen 361005, China