A high-capacity cathode for rechargeable K-metal battery based on reversible superoxide-peroxide conversion  

作　　者：Yu Qiao Han Deng Zhi Chang Xin Cao Huijun Yang Haoshen Zhou 

机构地区：[1]Center of Energy Storage Materials&Technology,College of Engineering and Applied Sciences,Jiangsu Key Laboratory of Artificial Functional Materials,National Laboratory of Solid State Microstructures,and Collaborative Innovation Center of Advanced Microstructures,Nanjing University,Nanjing 210093,China [2]Energy Technology Research Institute,National Institute of Advanced Industrial Science and Technology(AIST),1-1-1,Umezono,Tsukuba 305-8568,Japan

出　　处：《National Science Review》2021年第10期28-36,共9页国家科学评论（英文版）

基　　金：partially supported by the National Basic Research Program of China(2016YFB0100203);the National Natural Science Foundation of China(21633003,U1801251);the resources of the Advanced Photon Source,a US Department of Energy(DOE)Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No.DE-AC02–06CH11357。

摘　　要：As a promising low-cost energy storage device,the development of a rechargeable potassium-ion battery(KIB)is severely hindered by the limited capacity of cathode candidates.Regarded as an attractive capacity-boosting strategy,triggering the O-related anionic redox activity has not been achieved within a sealed KIB system.Herein,in contrast to the typical gaseous open K-O_(2) battery(O_(2)/KO_(2) redox),we originally realize the reversible superoxide/peroxide(KO_(2)/K_(2)O_(2))interconversion on a KO_(2)-based cathode.Controlled within a sealed cell environment,the irreversible O_(2) evolution and electrolyte decomposition(induced by superoxide anion(O_(2)-)formation)are effectively restrained.Rationally controlling the reversible depth-of-charge at 300 m Ah/g(based on the mass of KO_(2)),no obvious cell degradation can be observed during 900 cycles.Moreover,benefitting from electrolyte modification,the KO_(2)-based cathode is coupled with a limited amount of K-metal anode(merely 2.5 times excess),harvesting a K-metal full-cell with high energy efficiency(~90%)and long-term cycling stability(over 300 cycles).

关 键 词：ELECTROCHEMISTRY rechargeable battery beyond Li-ion battery long-term cycle life high capacity cathode 

分 类 号：TM912[电气工程—电力电子与电力传动]