Origin and Regulation of Interface Fusion during Synthesis of Single-Crystal Ni-Rich Cathodes

Lang Qiu; Mengke Zhang; Yang Song; Zhenguo Wu; Heng Zhang; Weibo Hua; Yan Sun; Qingquan Kong; Wei Feng; Ke Wang; Yao Xiao; Xiaodong Guo

doi:10.1002/anie.202300209

Origin and Regulation of Interface Fusion during Synthesis of Single-Crystal Ni-Rich Cathodes

Angew Chem Int Ed Engl. 2023 Mar 13;62(12):e202300209. doi: 10.1002/anie.202300209. Epub 2023 Feb 14.

Authors

Lang Qiu¹, Mengke Zhang¹, Yang Song¹, Zhenguo Wu¹, Heng Zhang², Weibo Hua¹, Yan Sun³, Qingquan Kong³, Wei Feng³, Ke Wang⁴, Yao Xiao⁵, Xiaodong Guo¹

Affiliations

¹ School of Chemical Engineering, Sichuan University, Chengdu, 610065, P. R. China.
² Institute of Materials Science and Devices, Suzhou University of Science and Technology, Suzhou, 215011, China.
³ School of Mechanical Engineering, Chengdu University, Chengdu, 610106, China.
⁴ Chemistry and Chemical Engineering Guangdong Laboratory, Shantou, 515031, China.
⁵ Institute for Carbon Neutralization, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang, 325035, China.

PMID: 36718610
DOI: 10.1002/anie.202300209

Abstract

Interface fusion plays a key role in constructing Ni-based single-crystal cathodes, and is governed by the atomic migration related to kinetics. However, the interfacial atom migration path and its control factors are lack of clearly understanding. Herein, we systematically probe the solid-state synthesis mechanism of single-crystal LiNi_0.92 Co_0.04 Mn_0.04 O₂ , including the effects of precursor size, Li/transition metal (TM) ratio and sintering temperature on the structure. Multi-dimensional analysis unravels that thermodynamics drives interface atoms migration through intermediate state (i.e., cation mixing phase) to induce grain boundary fusion. Moreover, we demonstrate that smaller precursor size (<6 μm), lager Li/TM ratio (>1.0) and higher temperature (≥810 °C) are conducive to promote the growth of the intermediate state due to reaction kinetics enhancement, and ultimately strengthen the atomic migration-induced interface fusion.

Keywords: Atoms Migration; Interface Fusion; Kinetics; Single-Crystal Cathodes.