Monitoring the phase evolution in LiCoO2 electrodes during battery cycles using in-situ neutron diffraction technique

LiCoO2 (LCO) with average particle distribution of 8 μm (LCO-A) and 11 μm (LCO-B) exhibit substantial differences in cycle performance. The half-cells have similar first-cycle discharge capacities of 173 and 175 mAh/g at 0.25 C, but after 100 cycles, the discharge capacities are substantially different, that is, 114 and 141 mAh/g for LCO-A and LCO-B, respectively. Operando neutron powder diffraction of full LCO||Li4Ti5O12 batteries show differences in the LCO reaction mechanism underpinning the electrochemical behavior. LCO-A follows a purely solid solution reaction during cycling compared to the solid solution and two-phase reaction mechanism in LCO-B. The absence of the two-phase reaction in LCO-A is consistent with a homogeneous distribution of Li throughout the particle. The two-phase reaction in LCO-B reflects two distinguishable distributions of Li within the particles. The faster capacity decay in LCO-A is correlated to an increase in electrode cracking during battery cycles. © 2019 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co.

Description

This special issue of the Journal of the Chinese Chemical Society is dedicated to Prof. Chien-Hong Cheng on the occasion of his 70th birthday. 12 articles/reviews representing cutting-edge research carried out by many of Prof. Cheng's friends, colleagues, former students and coworkers are collected in this issue.

Keywords

Phase transformations, Electric batteries, Electrodes, Lithium ions, Lithium, Cobalt, Oxides, Neutron diffraction

Citation

Jena, A., Lee, P.-H., Pang, W. K., Hsiao, K.-C., Peterson, V. K., Darwish, T., Yepuri, N., Wu, S.-H., Chang, H, & Liu, R.-S. (2020). Monitoring the phase evolution in LiCoO2 electrodes during battery cycles using in‐situ neutron diffraction technique. Journal of the Chinese Chemical Society, 67(3), 344-352. doi:10.1002/jccs.201900448