Direct Evidence of Reversible Changes in Electrolyte and its Interplay with LiO₂ Intermediate in Li-O₂ Batteries

Author(s)

Sousa, Bianca P. ; Lourenco, Tuanan C. ; Anchieta, Chayene G. ; Nepel, Thayane C. M. ; Filho, Rubens M. ; Da Silva, Juarez L. F. ; Doubek, Gustavo

• Document type: Journal article
• Source: SMALL; v. 20, n. 31, p. 11-pg., 2024-04-12.

Abstract

Lithium-oxygen batteries show promising energy storage potential with high theoretical energy density; however, further investigation of chemical reactions is required. In this study, experimental Raman and theoretical analyzes are performed for a Li-O-2 battery with LiClO4/dimethyl sulfoxide (DMSO) electrolyte and carbon cathode to understand the role of intermediate species in the reactional mechanism of the cell using a high donor number solvent. Operando Raman results reveal reversible changes in the DMSO bands, in addition to the formation and decomposition of Li2O2. On discharge, a decrease in DMSO polarizability is observed and bands of DMSO-Li+-anion interactions are evidenced and supported by ab initio density functional theory (DFT) calculations. Molecular dynamics (MD) force field simulations and operando Raman show that DMSO interacts with LiO2(sol), highlighting the stability of the electrolyte compared to the interaction with reactive O-2(-). On charging, the presence of Li+ indicates the formation of a lithium-deficient phase, followed by the release of Li+ and oxygen. Therefore, this study contributes to understanding the discharge/charge chemistry of a Li-O-2 cell, employing a common carbon cathode and DMSO electrolyte. The combination of a simple characterization technique in operando mode and theoretical studies provides essential information on the mechanism of Li-O-2 system. (AU)

• FAPESP's process: 17/11958-1 - CINE - Advanced Energy Storage Division
• Grantee: Rubens Maciel Filho
• Support Opportunities: Research Grants - Research Centers in Engineering Program
• FAPESP's process: 19/23681-0 - From ab initio to continuum methods to the screening of sodium-ion battery materials
• Grantee: Tuanan da Costa Lourenço
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 18/21401-7 - Multi-User Equipment approved in grant 2017/11631-2: cluster computational de alto desempenho - ENIAC
• Grantee: Juarez Lopes Ferreira da Silva
• Support Opportunities: Multi-user Equipment Program
• FAPESP's process: 17/11986-5 - Generation and storage of New Energy: bringing technological development for the country
• Grantee: Ana Flávia Nogueira
• Support Opportunities: Research Grants - Research Centers in Engineering Program
• FAPESP's process: 22/05652-5 - Polarizable force fields for the Investigation of sodium-ion battery materials
• Grantee: Tuanan da Costa Lourenço
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor
• FAPESP's process: 17/11631-2 - CINE: computational materials design based on atomistic simulations, meso-scale, multi-physics, and artificial intelligence for energy applications
• Grantee: Juarez Lopes Ferreira da Silva
• Support Opportunities: Research Grants - Research Centers in Engineering Program