Ionic Liquid-Type Additive for Lithium Metal Batteries Operated in LiPF6 Based-Electrolyte Containing 2500 ppm H2O.
ACS Appl Mater Interfaces
; 14(36): 41103-41113, 2022 Sep 14.
Article
em En
| MEDLINE
| ID: mdl-36044429
ABSTRACT
The presence of trace amounts of moisture in the electrolyte can cause hydrolysis of LiPF6 and deteriorate the stability of lithium metal batteries. Herein, we propose a multifunctional ionic liquid-type additive constituting a 1-methyl-1-butyl pyrrolidium cation (Py14+) and an acetate anion (CH3COO-) (denoted as IL-AC in this study), which can effectively adsorb the trace moisture and thus prevent the hydrolysis of LiPF6 via intermolecular interactions. The prepared IL-AC can also remove HF to suppress the dissolution of transition metal ions from cathode materials through the reaction CH3COO- + HF â CH3COOH + F-. Compared with the baseline electrolyte, the contents of HF and transition metal ions are significantly lower in the electrolyte with 0.5% IL-AC. Upon the addition of 0.5% IL-AC additive and 2500 ppm H2O, the Li||NCM811 battery shows a capacity of 153.7 mAh g-1 after 300 cycles, while the Li||LNMO battery possesses stable capacity retention of 93.22% after 500 cycles at 1C and a Coulombic efficiency greater than 99%. Thus, this work provides a convenient and effective method to absorb trace amounts of water and remove HF in the electrolyte and provides a new path for the expensive and tedious process of water removal from the electrolyte in industry.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article