Mechanistic Study of Electrolyte Additives to Stabilize High-Voltage Cathode–Electrolyte Interface in Lithium-Ion Batteries
- Argonne National Lab. (ANL), Lemont, IL (United States)
- BMW Group, Munich (Germany)
Current developments of electrolyte additives to stabilize electrode-electrolyte interface in Li-ion batteries highly rely on a trial-and-error search, which involves repetitive testing and intensive amount of resources. The lack of understandings on the fundamental protection mechanisms of the additives significantly increases the difficulty for the transformational development of new additives. In this study, we investigated two types of individual protection routes to build a robust cathode-electrolyte interphase at high potentials: (i) a direct reduction in the catalytic decomposition of the electrolyte solvent; and (ii) formation of a “corrosion inhibitor film” that prevents severely attack and passivation from protons that generated from the solvent oxidation, even the decomposition of solvent cannot not mitigated. Effect of three exemplary electrolyte additives: (i) lithium difluoro(oxalato)borate (LiDFOB); (ii) 3-hexylthiophene (3HT); and (iii) tris(hexafluoro-iso-propyl)phosphate (HFiP), on LiNi0.6Mn0.2Co0.2O2 (NMC 622) cathode were investigated to validate our hypothesis. It is demonstrated that understandings of both electrolyte additives and solvent are essential and careful balance between the cathode protection mechanism of additives and their side effects is critical to obtain optimum results. In conclusion, more importantly, this study opens up new directions of rational design of functional electrolyte additives for the next generation high-energy density lithium-ion chemistries.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (EE-3V)
- Grant/Contract Number:
- AC02-06CH11357
- OSTI ID:
- 1426673
- Journal Information:
- ACS Applied Materials and Interfaces, Journal Name: ACS Applied Materials and Interfaces Journal Issue: 51 Vol. 9; ISSN 1944-8244
- Publisher:
- American Chemical Society (ACS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English