Probing and suppressing voltage fade of Li-rich Li1.2Ni0.13Co0.13Mn0.54O2 cathode material for lithium-ion battery

• Published in: Electrochimica acta Vol. 318; pp. 875 - 882
• Main Authors: Zou, Wei, Xia, Fan-Jie, Song, Jian-Ping, Wu, Liang, Chen, Liang-Dan, Chen, Hao, Liu, Yang, Dong, Wen-Da, Wu, Si-Jia, Hu, Zhi-Yi, Liu, Jing, Wang, Hong-En, Chen, Li-Hua, Li, Yu, Peng, Dong-Liang, Su, Bao-Lian
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 20.09.2019; Elsevier BV
• Subjects: Cathodes; Cations; Cations rearrangement; Crystal structure; Discharge; Electrode materials; Li-rich cathode material; Lithium; Lithium-ion batteries; Rechargeable batteries; Structure change; Voltage fade; Lithium-ion batteries; Li-rich cathode material; Voltage fade; Cations rearrangement; Structure change
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2019.06.119

The voltage fade of Li-rich layered oxide cathode material Li1.2Ni0.13Co0.13Mn0.54O2 (LNCM) heavily hinders its application in Li-ion batteries. Herein, we revisit the origin of the voltage fade of LNCM and propose a solution to suppress this effect. It is demonstrated that the voltage fade of the LNCM cathode comes from the structural change of the crystal from layer structure to spinel structure, involving all the cations rearrangement. Such rearrangement of all the cations in LNCM is due to the high degree of delithiation and oxygen release at high cutoff voltage of 4.8 V. It is also evidenced that nickel and cobalt change from low valence to high valence at the discharged state, which not only inhibits the transport of lithium ions, but also leads to the loss of high voltage platforms. In particular, the cation rearrangement of Li/Mn causes valence change from Mn4+ to Mn3+, resulting in the decrease of discharge voltage platform at the cutoff voltage of 4.8 V much higher than at 4.6 V. The lower charge cutoff voltage can be a solution to suppress the voltage fade of LNCM cathode materials and have a good stability of LNCM cathode materials without compromising the battery performance. [Display omitted] •The voltage fade of Li1.2Ni0.13Co0.13 Mn0.54O2 comes from the layer to spinel structure.•All the cations rearrangement involves in the structure change.•Nickel and cobalt change from low valence to high valence at the discharged state.•The Mn4+ to Mn3+ in Mn rearrangement decreases the discharge voltage platform.•The lower charge cutoff voltage is a solution to suppress the voltage fade of Li1.2Ni0.13Co0.13 Mn0.54O2 without compromising the battery performance.