Inhibit the strain accumulation for 5V spinel cathode by mitigating the phase separation during high voltage stage

Liu, Saiyue; Liu, Xiang; Ren, Dongsheng; Li, Tianyi; Yi, Liang; Liu, Wei; Xu, Juping; Tan, Tiening; Zhang, Jiahao; Hou, Yukun; Guo, Yi; Zhu, Gaolong; Yin, Shuo; Yuan, Guohe; Weng, Yi; Ma, Guohua; Peng, Zuling; Zheng, Xiang; Yin, Wen; Lu, Languang; Ouyang, Minggao

doi:10.1016/j.nanoen.2023.109215

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Inhibit the strain accumulation for 5V spinel cathode by mitigating the phase separation during high voltage stage

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Abstract

LiNi 0.5 Mn 1.5 O 4 (LNMO) spinel cathode is a potential cathode material for high-power, low-cost lithium-ion batteries (LIBs) due to its low raw material cost, high operating voltage and efficient lithium-ion transport channel. However, LNMO suffers from structural stability due to the two-phase-transformation during charge/discharge process, leading to poor cycling performance. Here, to address the issues, we have constructed a homogeneous aggregated LNMO cathode with a multifaceted primary particle, namely the LNMO with single-crystal secondary particles (SSP LNMO). Ex situ and in situ characterizations including the synchrotron X-ray diffraction, the neutron diffraction and full pouch cell validated that the SSP LNMO exhibit a single solid-solution reactions with a restrained lattice evolution during the delithiation/lithiation process. This is in contrast to the normal LNMO cathode, which demonstrates a significant two-phase transition from spinel Li 1-x Ni 0.5 Mn 1.5 O 4 to rock-salt MnO 2 at high voltage. Therefore, the SSP LNMO has greatly improved cycle life compared to the normal LNMO cathode. Overall, this study demonstrates the possibility of constructing LNMO based on primary-grain morphology modulation to improve the intrinsic stability of LIBs.

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25 ENERGY STORAGE LiNi0.5Mn1.5O4 spinel cathode Lithium-ion batteries Phase transformation Structural stability

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Liu, Saiyue, Liu, Xiang, Ren, Dongsheng, Li, Tianyi, Yi, Liang, Liu, Wei, Xu, Juping, Tan, Tiening, Zhang, Jiahao, Hou, Yukun, Guo, Yi, Zhu, Gaolong, Yin, Shuo, Yuan, Guohe, Weng, Yi, Ma, Guohua, Peng, Zuling, Zheng, Xiang, Yin, Wen, Lu, Languang, Ouyang, Minggao. 2023-12-19. Inhibit the strain accumulation for 5V spinel cathode by mitigating the phase separation during high voltage stage. https://doi.org/10.1016/j.nanoen.2023.109215

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