Unusual double ligand holes as catalytic active sites in LiNiO2

Haoliang Huang; Yu-Chung Chang; Yu-Cheng Huang; Lili Li; Alexander C Komarek; Liu Hao Tjeng; Yuki Orikasa; Chih-Wen Pao; Ting-Shan Chan; Jin-Ming Chen; Shu-Chih Haw; Jing Zhou; Yifeng Wang; Hong-Ji Lin; Chien-Te Chen; Chung-Li Dong; Chang-Yang Kuo; Jian-Qiang Wang; Zhiwei Hu; Linjuan Zhang

doi:10.1038/s41467-023-37775-4

Unusual double ligand holes as catalytic active sites in LiNiO₂

Nat Commun. 2023 Apr 13;14(1):2112. doi: 10.1038/s41467-023-37775-4.

Authors

Haoliang Huang^#¹, Yu-Chung Chang^#², Yu-Cheng Huang³, Lili Li¹, Alexander C Komarek⁴, Liu Hao Tjeng⁴, Yuki Orikasa⁵, Chih-Wen Pao², Ting-Shan Chan², Jin-Ming Chen², Shu-Chih Haw², Jing Zhou¹, Yifeng Wang¹, Hong-Ji Lin², Chien-Te Chen², Chung-Li Dong³, Chang-Yang Kuo^{2

6}, Jian-Qiang Wang^{1

7}, Zhiwei Hu⁴, Linjuan Zhang^{8

9}

Affiliations

¹ Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800, China.
² National Synchrotron Radiation Research Center, Hsinchu, Taiwan, ROC.
³ Department of Physics, Tamkang University, New Taipei City, Taiwan, ROC.
⁴ Max Planck Institute for Chemical Physics of Solids, Dresden, 01187, Germany.
⁵ Department of Applied Chemistry, Ritsumeikan University, Kusatsu, Shiga, 535-8577, Japan.
⁶ Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan, ROC.
⁷ University of Chinese Academy of Sciences, Beijing, 10049, China.
⁸ Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, 201800, China. zhanglinjuan@sinap.ac.cn.
⁹ University of Chinese Academy of Sciences, Beijing, 10049, China. zhanglinjuan@sinap.ac.cn.

^# Contributed equally.

Abstract

Designing efficient catalyst for the oxygen evolution reaction (OER) is of importance for energy conversion devices. The anionic redox allows formation of O-O bonds and offers higher OER activity than the conventional metal sites. Here, we successfully prepare LiNiO₂ with a dominant 3d⁸L configuration (L is a hole at O 2p) under high oxygen pressure, and achieve a double ligand holes 3d⁸L² under OER since one electron removal occurs at O 2p orbitals for Ni^III oxides. LiNiO₂ exhibits super-efficient OER activity among LiMO₂, RMO₃ (M = transition metal, R = rare earth) and other unary 3d catalysts. Multiple in situ/operando spectroscopies reveal Ni^III→Ni^IV transition together with Li-removal during OER. Our theory indicates that Ni^IV (3d⁸L²) leads to direct O-O coupling between lattice oxygen and *O intermediates accelerating the OER activity. These findings highlight a new way to design the lattice oxygen redox with enough ligand holes created in OER process.