Enhanced Cycle Life and Rate Capability of Single-Crystal, Ni-Rich LiNi0.9Co0.05Mn0.05O2 Enabled by 1,2,4-1 H-Triazole Additive

Yue Zou; Ke Zhou; Gaopan Liu; Ningbo Xu; Xiaozhen Zhang; Yong Yang; Jing Zhang; Jianming Zheng

doi:10.1021/acsami.1c02043

Enhanced Cycle Life and Rate Capability of Single-Crystal, Ni-Rich LiNi_0.9Co_0.05Mn_0.05O₂ Enabled by 1,2,4-1 H-Triazole Additive

ACS Appl Mater Interfaces. 2021 Apr 14;13(14):16427-16436. doi: 10.1021/acsami.1c02043. Epub 2021 Mar 31.

Authors

Yue Zou¹, Ke Zhou¹, Gaopan Liu¹, Ningbo Xu¹, Xiaozhen Zhang¹, Yong Yang^{1

2

3}, Jing Zhang¹, Jianming Zheng¹

Affiliations

¹ State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
² Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Xiamen University, Xiamen 361005, China.
³ School of Energy Research, Xiamen University, Xiamen 361005, China.

PMID: 33788530
DOI: 10.1021/acsami.1c02043

Abstract

Ternary LiNi_xCo_yMn_zO₂ oxides with extremely high nickel (Ni) contents (x ≥ 0.9) are promising cathode candidates developed for higher-energy-density lithium-ion batteries, with an aim to relieve mileage anxiety. However, the structural and interfacial instability still restrict their application in electric vehicles. In this work, a novel electrolyte additive 1,2,4-1H-Triazole (HTZ) is introduced to improve the interfacial stability of LiNi_0.9Co_0.05Mn_0.05O₂ (NCM90), promoting cycle life both at 30 °C and a harsh condition of 60 °C, as well as rate capability. The NCM90||Li cells with 0.3% HTZ-added electrolyte retain 86.6% of their original capacity after 150 cycles at 1C and 30 °C, well exceeding 74.8% obtained with the baseline electrolyte. It is revealed that the additive HTZ could inhibit the thermal decomposition of LiPF₆ salt and suppress the generation of HF acidic species. More importantly, additive HTZ is preferentially oxidized to construct a compact and dense cathode electrolyte interphase (CEI) layer, which is beneficial for stabilizing the electrode/electrolyte interface and suppressing unwanted side reactions.

Keywords: 1,2,4-1H-Triazole (HTZ); Ni-rich NCM cathode; cathode electrolyte interphase (CEI); electrolyte additive; lithium-ion batteries.