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Realizing Complete Solid‐Solution Reaction in High Sodium Content P2‐Type Cathode for High‐Performance Sodium‐Ion Batteries
Author(s) -
Jin Ting,
Wang PengFei,
Wang QinChao,
Zhu Kunjie,
Deng Tao,
Zhang Jiaxun,
Zhang Wei,
Yang XiaoQing,
Jiao Lifang,
Wang Chunsheng
Publication year - 2020
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.202003972
Subject(s) - cathode , sodium , vacancy defect , ion , capacity loss , phase (matter) , materials science , chemistry , solid solution , extraction (chemistry) , analytical chemistry (journal) , anode , crystallography , electrode , chromatography , metallurgy , organic chemistry
P2‐type layered oxides suffer from an ordered Na + /vacancy arrangement and P2→O2/OP4 phase transitions, leading them to exhibit multiple voltage plateaus upon Na + extraction/insertion. The deficient sodium in the P2‐type cathode easily induces the bad structural stability at deep desodiation states and limited reversible capacity during Na + de/insertion. These drawbacks cause poor rate capability and fast capacity decay in most P2‐type layered oxides. To address these challenges, a novel high sodium content (0.85) and plateau‐free P2‐type cathode‐Na 0.85 Li 0.12 Ni 0.22 Mn 0.66 O 2 (P2‐NLNMO) was developed. The complete solid‐solution reaction over a wide voltage range ensures both fast Na + mobility (10 −11 to 10 −10 cm 2 s −1 ) and small volume variation (1.7 %). The high sodium content P2‐NLNMO exhibits a higher reversible capacity of 123.4 mA h g −1 , superior rate capability of 79.3 mA h g −1 at 20 C, and 85.4 % capacity retention after 500 cycles at 5 C. The sufficient Na and complete solid‐solution reaction are critical to realizing high‐performance P2‐type cathodes for sodium‐ion batteries.