Integrated multi-scale synchrotron radiation-technology studies on AlPO_(4)-coating modification mechanism in lithium-rich manganese-based cathode  

作　　者：Zhong-Qin Dai Huan Chen Zhao-Yin Wen 

机构地区：[1]School of Physical Science and Technology,ShanghaiTech University,Shanghai 201210,China [2]The State Key Lab High-Performance Ceram&Superfine,Shanghai Institute of Ceramics,Chinese Academy of Sciences,Shanghai 200050,China [3]University of Chinese Academy of Science,Beijing 100049,China

出　　处：《Nuclear Science and Techniques》2025年第5期30-42,共13页核技术(英文)

基　　金：supported by the National Key R&D Program of China(No.2022YFB3807700);National Natural Science Foundation of China(Nos.U20A20248 and 52372247);Shanghai Pujiang Programme(23PJD110);Science and Technology Commission of Shanghai Municipality(No.18DZ2280800)。

摘　　要：Lithium-and manganese-rich(LMR)oxide cathode materials are among the most attractive candidates for next-generation energy-storage materials owing to their anomalous capacity.However,severe Mn dissolution that occurs during long-term cycling,which leads to capacity loss,hinders their application prospects.In this study,nanoscale AlPO_(4)-coated Li_(1.2)Ni_(0.13)Co_(0.13)Mn_(0.54)O_(2)(LMR@APO)with significantly enhanced electrochemical performance is successfully synthesized using a simple and effective sol–gel method to mitigate Mn dissolution and suppress local structural distortion at high voltages.Because of the complex evolution of the structure and oxidation state of LMR materials during electrochemical cycling,observing and analyzing them using traditional single characterization methods may be difficult.Therefore,we combine various synchrotron-based characterization techniques to conduct a detailed analysis of the electronic and coordination structures of the cathode material from the surface to the bulk.Synchrotron-based hard and soft X-ray spectroscopies are integrated to investigate the differences in O and Mn evolution between the surfaces and bulk of the cathode.Advanced synchrotron-based transmission X-ray microscopy combined with X-ray near-edge absorption-structure technology is utilized to visualize the two-dimensional nanometer-scale reactivity of the LMR cathode.The AlPO_(4)-coating layer can stabilize the surface structure of the LMR material,effectively alleviating irreversible oxygen release on the surface and preventing the dissolution of Mn^(2+)at the interface caused by side reactions after a long cycle.Therefore,the spatial reaction uniformity of Mn is enhanced by the AlPO_(4)-coating layer,and rapid capacity decay caused by Mn deactivation is prevented.The AlPO_(4)-coating method is a facile modification strategy for high-performance LMR materials.

关 键 词：Synchrotron radiation X-ray absorption fine structure X-ray imaging Amorphous coating layer Lithium-and manganese-rich(LMR)cathode 

分 类 号：TM912[电气工程—电力电子与电力传动]