Journal
NANO LETTERS
Volume 15, Issue 12, Pages 8371-8376Publisher
AMER CHEMICAL SOC
DOI: 10.1021/acs.nanolett.5b04097
Keywords
Energy storage; Li-O-2 battery; electrochemistry; oxygen evolution reactions; ionic liquids
Categories
Funding
- Boston College
Ask authors/readers for more resources
As a promising high-capacity energy storage technology, Li-O-2 batteries face two critical challenges, poor cycle lifetime and low round-trip efficiencies, both of which are connected to the high overpotentials. The problem is particularly acute during recharge, where the reactions typically follow two-electron mechanisms that are inherently slow. Here we present a strategy that can significantly reduce recharge overpotentials. Our approach seeks to promote Li2O2 decomposition by one-electron processes, and the key is to stabilize the important intermediate of superoxide species. With the introduction of a highly polarizing electrolyte, we observe that recharge processes are successfully switched from a two-electron pathway to a single-electron one. While a similar one-electron route has been reported for the discharge processes, it has rarely been described for recharge except for the initial stage due to the poor mobilities of surface bound superoxide ions (O-2(-)), a necessary intermediate for the mechanism. Key to our observation is the solvation of O-2(-) by an ionic liquid electrolyte (PYR14TESI). Recharge overpotentials as low as 0.19 V at 100 mA/g(carbon) are measured.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available