K doping stabilizes three-dimensional K_(0.2)Na_(1.3)Mn_(0.5)O_(2-δ)as high-performance cathode for sodium-ion batteries  

作　　者：Jia-Hao Xu You-Huan Zhu Wei-Min Yang Hua Cheng Zhou-Guang Lu 

机构地区：[1]Industrial Training Center,Shenzhen Polytechnic University,Shenzhen 518055,China [2]Department of Materials Science and Engineering,Southern University of Science and Technology,Shenzhen 518055,China [3]School of Materials Science and Environmental Engineering,Shenzhen Polytechnic University,Shenzhen 518055,China

出　　处：《Rare Metals》2024年第10期5030-5038,共9页稀有金属（英文版）

基　　金：financially supported by the Scientific Research Startup Fund for Shenzhen High-Caliber Personnel of SZPT(No.6021310029K);Research Projects of Department of Education of Guangdong Province(No.2023KTSCX319)。

摘　　要：It is a difficult challenge to simultaneously employ the cationic and anionic redox chemistry in cathode materials for sodium-ion batteries with high energy.Even though layered oxides(classified as two-dimensional oxides)demonstrate excellent promise in the high discharge capacity,their poor oxygen transformation via redox reactions is limited by crystal instability.Therefore,a doping strategy was conceived to tackle this issue and increase redox efficiency.K doping was applied to transform the two-dimensional Na_(1.3)Mn_(0.7)O_(2)(NMO)to threedimensional K_(0.2)Na_(1.3)Mn_(0.5)O_(2)(KNMO),preventing the irreversible phase shift and preserving the crystal structure’s stability while cycling.With this modification treatment,KNMO features manganese and oxygen reactive sites,delivering a promising energy density of 190mAh·g^(-1)at 5 mA·g^(-1)in the 2.0–4.5 V voltage range(vs71.4 mAh·g^(-1)for the pristine NMO).Moreover,it displays improved capacity retention of more than 83.5%after 50cycles at 50 mA·g^(-1).The results demonstrated that doped intercalation oxides were promising for redox oxygen transformation in sodium-ion batteries.

关 键 词：High-performance cathode Metal ion dopings Sodium-ion batteries Three-dimensional structure 

分 类 号：TM912[电气工程—电力电子与电力传动]