Understanding the Stability of LiNi0.5Mn0.5O2 as a Co-Free Positive Electrode

Xinyi Liu; Dongyan Zhang; Maolin Zhang; Yangxi Yan; Zhimin Li; Pangpang Wang; Ri-Ichi Murakami

doi:10.1021/acs.jpclett.2c01126

Understanding the Stability of LiNi_0.5Mn_0.5O₂ as a Co-Free Positive Electrode

J Phys Chem Lett. 2022 Jul 7;13(26):6181-6186. doi: 10.1021/acs.jpclett.2c01126. Epub 2022 Jun 29.

Authors

Xinyi Liu¹, Dongyan Zhang¹, Maolin Zhang¹, Yangxi Yan¹, Zhimin Li¹, Pangpang Wang², Ri-Ichi Murakami³

Affiliations

¹ School of Advanced Materials and Nanotechnology, Xidian University, Xi'an, Shaanxi 710126, People's Republic of China.
² Nanomaterials Group, Institute of System, Information Technologies and Nanotechnologies (ISIT), Fukuoka Industry-Academia Symphonicity (FiaS), 4-1 Kyudaishinmachi, Nishi-ku, Fukuoka 819-0388, Japan.
³ School of Mechanical Engineering, Chengdu University, Chengdu, Sichuan 610106, People's Republic of China.

PMID: 35767230
DOI: 10.1021/acs.jpclett.2c01126

Abstract

To understand the stability of Co-free positive electrode materials, LiNi_0.5Mn_0.5O₂ was synthesized with different amounts of lithium added during calcination. The valence states of the Ni and Mn transition metals of the prepared samples were determined through accurate stoichiometry analyses (via inductively coupled plasma optical emission spectrometry), magnetic moment measurements (via superconducting quantum interference device magnetometry), and element valence analyses (via X-ray spectroscopy in combination with Ar ion etching for depth profiling). Unexpectedly, the Ni and Mn transition metals in the interior and on the surface of the LiNi_0.5Mn_0.5O₂ particles show different electrochemical properties. This clarifies the open questions on the Li deintercalation mechanism in LiNi_0.5Mn_0.5O₂.