Promoting amorphization of commercial TiO_(2) upon sodiation to boost the sodium storage performance  

作　　者：Tao Li Ling-Yun Kong Xue Bai Yan-Xiang Wang Yong-Xin Qi 

机构地区：[1]Key Laboratory of Liquid-Solid Structural Evolution and Processing of Materials of Ministry of Education,State Key Laboratory of Crystal Materials,Shandong University,Jinan 250061,Shandong,China [2]School of Materials Science and Engineering,Shandong University of Science and Technology,Qingdao 266590,Shandong,China

出　　处：《Journal of Energy Chemistry》2023年第6期379-388,I0009,共11页能源化学（英文版）

基　　金：financially supported by the Shandong Provincial Natural Science Foundation,China (Grant No.ZR2022QE181)。

摘　　要：Anatase TiO_(2) is a promising anode material for sodium-ion batteries,yet the low electronic and ionic conductivities are the main obstacles for its practical application.Even though the amorphization of TiO_(2) upon sodiation has already been observed,its underneath mechanisms are not fully elucidated.Herein,a low-cost nitrogen-containing carbon source of polyacrylonitrile is adopted to modify commercial anatase TiO_(2) by a convenient and nontoxic ball-milling technique combined with subsequent annealing treatment.In particular,the employment of a nitrogen-doping approach accompanied by nitrogendoped carbon coating,results in a greatly improved conductivity,overall leading to a high reversible capacity of about 260 m A h g^(-1)at 25 m A g^(-1),superior rate capabilities,and an ultra-stable capacity of about 186 m A h g^(-1)after 1600 cycles at 500 m A g^(-1).Detailed characterizations denote that the improved conductivity as well as the small size of the synthesized TiO_(2) grains play a key role in the TiO_(2) amorphization upon sodiation,with the TiO_(2)/C nanocomposite undergoing a complete amorphization in just few cycles.Finally,the irreversible amorphization of TiO_(2) is confirmed to be a crucial ingredient facilitating the Na+diffusion kinetics and pseudocapacitive behavior,thus boosting the sodium storage performance.

关 键 词：Commercial TiO_(2) Anode material Amorphization Nitrogen doping Sodium-ion battery 

分 类 号：TM912[电气工程—电力电子与电力传动] TQ134.11[化学工程—无机化工]