Fluorine-substituted O3-type NaNi_(0.4)Mn_(0.25)Ti_(0.3)Co_(0.05)O_(2-x)F_(x) cathode with improved rate capability and cyclic stability for sodium-ion storage at high voltage  

作　　者：Chaojin Zhou Lichun Yang Chaogang Zhou Jiangwen Liu Renzong Hu Jun Liu Min Zhu 

机构地区：[1]School of Materials Science and Engineering,Guangdong Provincial Key Laboratory of Advanced Energy Storage Materials,South China University of Technology,Guangzhou 510641,Guangdong,China [2]College of Metallurgy and Energy,Key Laboratory of the Ministry of Education for Modern Metallurgy Technology,North China University of Science and Technology,Tangshan 063210,Hebei,China

出　　处：《Journal of Energy Chemistry》2021年第9期341-350,共10页能源化学（英文版）

基　　金：financial support from the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (No. NSFC51621001);the Guangdong Special Support Program (2017TQ04N224);the Guangdong Natural Science Funds for Distinguished Young Scholar (Grant No. 2017B030306004);the Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme。

摘　　要：O3-type Na NiO_(2)-based cathode materials undergo irreversible phase transition and serious capacity decay at high voltage above 4.0 V in sodium-ion batteries. To address these challenges, effects of Fsubstitution on the structure and electrochemical performance of Na Ni_(0.4)Mn_(0.25)Ti_(0.3)Co_(0.05)O_(2) are investigated in this article. The F-substitution leads to expanding of interlayer, which can enhance the mobility of Na+. NaNi_(0.4)Mn_(0.25)Ti_(0.3)Co_(0.05)O_(1.92)F_(0.08)(NMTC-F_(0.08)) with the optimal F-substitution degree exhibits much improved rate capability and cyclic stability. It delivers reversible capacities of 177 and 97 m Ah g^(-1) at 0.05 and 5 C within 2.0–4.4 V, respectively. Galvanostatic intermittent titration technique verifies faster kinetics of Na+diffusion in NMTC-F_(0.08). And in-situ XRD investigation reveals the phase evolution of NMTC-F_(0.08), indicating enhanced structural stability results from F-substitution. This study may shed light on the development of high performance cathode materials for sodium-ion storage at high voltage.

关 键 词：F-substitution Sol-gel method O3-type cathode Sodium-ion battery High-voltage cathode 

分 类 号：TM912[电气工程—电力电子与电力传动] TQ131.12[化学工程—无机化工]