层状高熵正极储钾材料的制备及钼的掺杂效应  

Preparation of Layered High-entropy Cathode Materials for Potassium-ion Storage and Doping Effects of Molybdenum

作　　者：常舫菲 蔡宇晴 刘乾 柏玲[1] 黄镇东[1] CHANG Fangfei;CAI Yuqing;LIU Qian;BAI Ling;HUANG Zhendong(State Key Laboratory for Organic Electronics and Information Displays,Nanjing University of Posts and Telecommunications,Nanjing 210023,China)

机构地区：[1]南京邮电大学、材料科学与工程学院、省部共建有机电子与信息显示国家重点实验室,江苏南京210023

出　　处：《广州化学》2025年第1期26-33,I0002,共9页Guangzhou Chemistry

基　　金：国家自然科学基金面上项目(52277219)。

摘　　要：为克服锰基层状氧化物正极工作中Mn^(3+)的Jahn-Teller效应、Mn^(2+)溶解现象及连续循环过程中多次相变引起的体积变化对锰基层状氧化物正极电化学性能稳定性的影响,通过多元掺杂提升层状氧化物熵值、提高电导率、稳定结构被认为是提升锰基层状氧化物正极最为有效、也是最为常见的手段之一。本文采用球磨混料+高温固相烧结相结合的方式制备了K_(0.5)(NiFeMg)_(0.05)Mn_(0.85)O_(2)、K_(0.5)(NiFeMgMo)_(0.05)Mn_(0.8)O_(2)、K_(0.5)(NiFeMgAlMo)_(0.04)Mn_(0.8)O_(2)、K_(0.5)(NiFeMgZr)_(0.05)Mn_(0.8)O_(2)、K_(0.5)(NiFeMgZrMo)_(0.05)Mn_(0.8)O_(2)五种中高熵层状材料,通过X射线衍射、扫描和透射电子显微镜等手段表征了各材料的物理化学性质,通过电化学工作站和恒流充放电仪等设备测试和表征各材料的电化学储钾性能和行为,重点研究和揭示了钼元素的掺杂表现出对锰基层状氧化物正极多级相变储钾机制的稳定效应,结果表明该材料有别于大部分元素掺杂随着熵值的增加出现由相变向固溶转变的现象。To overcome the effect of Jahn-Teller effect of Mn^(3+),dissolution of Mn^(2+),and volume changes caused by multiple phase transitions during continuous cycling processes of manganese-based layered oxide cathode materials to their electrochemical stability,multi-element doping to increase the entropy value of layered oxides is considered to be one of the most effective and common methods to improve conductivity,and stabilize structure of manganese-based layered oxides.In this study,medium-K_(0.5)(NiFeMg)_(0.05)Mn_(0.85)O_(2),high-entropy layered oxides materials of K_(0.5)(NiFeMgMo)_(0.05)Mn_(0.8)O_(2),K_(0.5)(NiFeMgAlMo)_(0.04)Mn_(0.8)O_(2),K_(0.5)(NiFeMgZr)_(0.05)Mn_(0.8)O_(2),and K_(0.5)(NiFeMgZrMo)_(0.05)Mn_(0.8)O_(2) were prepared by using a ball-milling assisted high-temperature solid-phase sintering method.The physical and chemical properties of each material have been characterized by using X-ray diffraction,scanning/transmission electron microscopy,and other methods.The potassium-storage performance and behavior of each material were tested and characterized by using the electrochemical workstation and constant current charge-discharge tester.Herein,we put the emphasis on the understanding and revealing the stabilization effect of the doped molybdenum to the multi-phase transition potassium-ion storage mechanism of manganese-based layered oxide cathodes,which differs from the doping effect of the most element which can help to achieve the transition from phase transformation to solid solution mechanism with the increase of entropy value.

关 键 词：钾离子电池 高熵氧化物 层状过渡金属氧化物 正极材料 钼 

分 类 号：TQ152[化学工程—电化学工业]