Fluorine-doped K_(0.39)Mn_(0.77)Ni_(0.23)O_(1.9)F_(0.1) microspheres with highly reversible oxygen redox reaction for potassium-ion battery cathode  

作　　者：Zhuangzhuang Zhang Yaru Qiao Jun Zhao Dai-Huo Liu Mengmin Jia Hongwei Tang Liang Wang Dongmei Dai Bao Li 

机构地区：[1]Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals,Key Laboratory of Green Chemical Media and Reactions(Ministry of Education),School of Chemistry and Chemical Engineering,Henan Normal University,Xinxiang 453007,China

出　　处：《Chinese Chemical Letters》2025年第3期517-521,共5页中国化学快报(英文版)

基　　金：financially supported by the National Natural Science Foundation of China(No.51902090);Henan Key Research Project Plan for Higher Education Institutions(No.24A150019);the Doctoral Start-Up Foundation(No.QD2022017).

摘　　要：Mn-rich layered oxides are appealing cathodes for potassium ion batteries(PIBs)in view of their comprehensive virtues such as low cost,high energy density and mature craftsmanship.However,the insufficient covalency between transition metal(TM)and O usually induces irreversible structural evolution and cation migration during repeated insertion and extraction of K^(+),resulting in capacity loss,voltage fading and sluggish kinetics.Herein,an anion substitution strategy is proposed for a stable operation of layered oxide cathode by adjusting the valence electron layer structure between TM and O.The resultant strong TM−O skeleton can inhibit the occurrence of side effects derive from Ni^(4+)during the deep depotassium process,so as to achieve a gentle structural transition.Consequently,stable cycling performance of K_(0.39)Mn_(0.77)Ni_(0.23_O_(1.9)F_(0.1)(KMNOF)cathode is achieved with 77%capacity retention over 350 cycles at 100mA/g,yielding high discharge capacity 93.5 mAh/g at 20mA/g and significantly improved rate capability of 50.1 mAh/g at 500 mA/g,whereas irreversible structural evolution and rapid capacity fade with KMNO cathode.Finally,in situ/ex situ characterizations and theoretical computations sheds light on the charge transfer and structure evolution mechanisms of KMNOF.

关 键 词：Layered oxides CATHODE TM-O bond Potassium ion batteries Anion-doping 

分 类 号：TM912[电气工程—电力电子与电力传动]