Novel metallic titanium fluoride: A promising high capacity and superionic conductivity anode in Li-, Na-, and K-ion batteries
Min Zhou, Yanqing Shen, Jiajia Liu, Lingling Lv, Yu Zhang, Xianghui Meng, Xin Yang, Yangdong Zheng, Zhongxiang Zhou
Abstract
The transition metal fluorides have huge advantage as anode due to the small atomic mass of the F atom. But the formation of Li–F rings reduced the cycle life, and the open-framework structure induced the high diffusion barriers. We designed a non-open framework 1T-TiF 2 structure. The remaining 3d electrons of Ti induced the 1T-TiF 2 structure has good electronic conductivity, and large formation energy of 1T-TiF 2 structure block the formation of Li–F rings. The 1T-TiF 2 structure could serve as anode in Li-ion, Na-ion, and K-ion batteries with high stiffness, superionic conductivity and long cycle life. Our calculate results indicated that the 1T-TiF 2 anode has competitive theoretical capacitance (208.08 mA h g −1 for Li-ion battery, 277.45 mA h g −1 for Na-ion battery, and 208.08 mA h g −1 for K-ion battery). Furthermore, the good thermal, dynamic stability, oxidative corrosion resistance , and hydrophilicity confirmed the possibility of preparing 1T-TiF 2 structure under laboratory conditions. Our study provides a reference for the light weighting of anodes.