A uniform and high-voltage stable LiTMPO4 coating layer enabled high performance LiNi0.8Co0.15Mn0.05O2 towards boosting lithium storage

Hang Dong; Du Sun; Miao Xie; Mingzhi Cai; Zhuang Zhang; Tianxun Cai; Wujie Dong; Fuqiang Huang

doi:10.1039/d2dt01296k

A uniform and high-voltage stable LiTMPO₄ coating layer enabled high performance LiNi_0.8Co_0.15Mn_0.05O₂ towards boosting lithium storage

Dalton Trans. 2022 Aug 23;51(33):12532-12539. doi: 10.1039/d2dt01296k.

Authors

Hang Dong^{1

2}, Du Sun¹, Miao Xie^{1

2}, Mingzhi Cai³, Zhuang Zhang^{1

2}, Tianxun Cai^{1

2}, Wujie Dong¹, Fuqiang Huang^{1

3}

Affiliations

¹ State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China. dongwujie@mail.sic.ac.cn.
² Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Science, Beijing 100049, China.
³ State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.

PMID: 35912983
DOI: 10.1039/d2dt01296k

Abstract

LiTMPO₄ materials, such as LiNiPO₄, can maintain structural stability and Li⁺ transport activity up to 4.8 V, showing great potential to stabilize layered nickel-rich cathodes at high voltage. But achieving a uniform LiTMPO₄ coating layer remains a great challenge. Herein, an ultrathin and uniform LiTMPO₄ layer (mainly LiNiPO₄) is successfully coated on the surface of LiNi_0.8Co_0.15Mn_0.05O₂ (NMC@LTMP) via utilizing the surface chelation of phytic acid with NMC precursors and a subsequent high-temperature in situ reaction. The reconstructed surface and interface could act as stable paths for Li⁺ transport and efficient barriers against electrolyte corrosion. Thus, harmful side reactions like solid electrolyte interphase overgrowth, irreversible phase transformation, and metal dissolution are inhibited simultaneously. Impressively, the optimized NMC@LTMP2 cathode exhibits remarkably improved capacity, as high as 215 mA h g^-1 at 2.8-4.5 V, with capacity retention of 87.21% after 200 cycles and outstanding rate capability of 140 mA h g^-1 at 10C, significantly better than a pristine cathode. Furthermore, a pouch cell assembled with an NMC@LTMP2 cathode and graphite anode also exhibits robust capacity retention of 82.42% after 100 cycles. These results provide useful insights towards enabling the application of NMC cathodes via developing facile modification methods.