Decoding Li+/Na+ Exchange Route Toward High‐Performance Mn‐Based Layered Cathodes for Li‐Ion Batteries

• DOI: 10.1002/adfm.202214921
• Publication Date: 2023-02-18T17:36:08Z
• Authors: Bo Cao; Zhefeng Chen; Hongbin Cao; Chen Zhu; Hongkai Yang; Tianyi Li; Wenqian Xu; Feng Pan; Mingjian Zhang
• Keywords: 02 engineering and technology; 0210 nano-technology; 01 natural sciences; 7. Clean energy; 0104 chemical sciences

Abstract Li + /Na exchange has been extensively explored as an effective method to prepare high‐performance Mn‐based layered cathodes for Li‐ion batteries, since the first report in 1996 by P. G. Bruce (Nature, 1996. 381, 499–500). Understanding detailed structural changes during ion‐exchange process is crucial implement synthetic control of cathodes, but less studied. Herein, situ synchrotron X‐ray diffraction, density functional theory calculations, and electrochemical tests are combined conduct systemic studies into Mn‐only cathode O3‐type 0.67 [Li 0.22 Mn 0.78 ]O 2 (LLMO) from corresponding counterpart P3‐type Na (NLMO). The temperature‐resolved observations with theoretical calculations reveal that favorable thermodynamically composited two tandem topotactic phase transitions: 1) NLMO a intermediate through ≈60% exchange. 2) then final product LLMO further insertion. Moreover, intermediate‐dominate composite obtained slowing down kinetics below room temperature, showing better performance than traditional molten‐salt method. findings provide guides under mild conditions.