文献类型：期刊文献

英文题名：Relaxing the Jahn-Teller distortion of LiMn0.6Fe0.4PO4 cathodes via Mg/Ni dual-doping for high-rate and long-life Li-ion batteries

作者：Yu, Haifeng[1,2];Zhang, Erdong[3];Yu, Jinxun[2];Yu, Songmin[2];Fang, Yaoguo[3];Chen, Ling[1,2];Jiang, Hao[1,2];Li, Chunzhong[1,2]

机构：[1]East China Univ Sci & Technol, Shanghai Engn Res Ctr Hierarch Nanomat, Sch Chem Engn, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Sch Mat Sci & Engn, Key Lab Ultrafine Mat, Minist Educ, Shanghai 200237, Peoples R China;[3]Shanghai Xuanyi New Energy Dev Co Ltd, Shanghai 201800, Peoples R China

年份：2024

卷号：12

期号：38

起止页码：26076

外文期刊名：JOURNAL OF MATERIALS CHEMISTRY A

收录：;EI(收录号：20243717036152);WOS:【SCI-EXPANDED(收录号:WOS:001310294200001)】；

基金：This work was supported by the National Natural Science Foundation of China (22308103), Shanghai Pilot Program for Basic Research (22TQ1400100-13), Postdoctoral Fellowship Program of CPSF (GZB20230214), China Postdoctoral Science Foundation (2023M731083), and the Fundamental Research Funds for the Central Universities.

语种：英文

外文关键词：Jahn-Teller effect - Photoionization - State of charge

摘要：Olivine-type LiMnxFe1-xPO4 (LMFP, 0 < x < 1) is poised to supplant LiFePO4 cathode materials with a similar to 20% energy-density increase for Li-ion batteries (LIBs). However, its intrinsic low conductivities and MnO6 octahedral unit-cell Jahn-Teller distortion limit its power capability and cycling life. Herein, we report a Mg/Ni dual-doped and carbon-coated LMFP micro-sized secondary sphere with greatly enhanced reaction kinetics and superior structure stability. Ni2+ reduces the average valence state of Mn ions to alleviate Jahn-Teller distortion by participating in charge compensation during charging while improving electronic conductivity together with carbon coating. Mg2+ with a smaller ion radius (65 pm) significantly widens the Li-ion transfer channel by extending Li-O bonds. The as-obtained LMFP cathodes increase reversible specific capacity by about 2.4 times at 5C compared with a pristine sample, reaching 115 mA h g(-1). In a pouch-type full cell, 92% of its initial capacity is still maintained after 2000 cycles at 1C, demonstrating its attractive potential for practical application in high-power and long-life LIBs.