Investigations of an organic coverage to Ni-rich cathode materials: Effects on deteriorated, cathode electrolyte interphase, and chemical crossover
Journal
Journal of Energy Storage
Journal Volume
92
ISSN
2352-152X
Date Issued
2024-07-01
Author(s)
Rio Akbar Yuwono
Chusnul Khotimah
Fu-Ming Wang
Arif Cahyo Imawan
Ruben Foeng
Pin-Cheng Huang
Guan-Yi Liu
Shu-Chih Haw
Hwo-Shuenn Sheu
DOI
10.1016/j.est.2024.112184
Abstract
Ni-rich cathodes inherit surface residual lithium compounds (SRLCs) for several reasons, such as cation mixing, oxygen vacancies, and the spontaneous reduction of high-Ni valence ions. Consequently, Ni-rich compounds must be treated before use to maximize their performance. This study describes the development of an organic coverage (OC) that can be directly utilized with a deteriorated Ni-rich cathode. The OC is synthesized from 5,5-dimethylbarbituric acid and polyethylene glycol diacrylate to provide two functions for the deteriorated Ni-rich cathode surface: spontaneous ion exchange and the self-electrochemical oxidation of Ni ions. SRLCs, such as Li2CO3 and LiOH, decompose through a transformation reaction from the trioxo to the dioxo form of the OC structure. Then this lithiated OC forms an organic artificial cathode electrolyte interface on the cathode surface, which further reduces the effects of chemical crossover on the anode side. It is also believed that the dioxo form promotes Ni2+ self-oxidation on the surface of Ni-rich cathodes and recovers the original Ni3+ valence state by Li+ re-intercalation. Thus, the capacities of the deteriorated LiNiO2 and LiNi0.8Mn0.1Co0.1O2 recover almost to their original values and retain the same excellent cycle performance as that of the fresh compounds.
Subjects
Cathode electrolyte interphase
Li2CO3
Ni-rich
Organic coverage
Self-oxidation
Spontaneous ion exchange
Publisher
Elsevier BV
Description
Article number 112184
Type
journal article