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Stabilizing Li Anodes in I2 Steam to Tackle the Shuttling-Induced Depletion of an Iodide/Triiodide Redox Mediator in Li–O2 Batteries with Suppressed Li Dendrite Growth

Authors :
Wei Zhou
Zongping Shao
Zhichao Cheng
Kaiming Liao
Ran Ran
Xiaohong Zou
Qian Lu
Source :
ACS Applied Materials & Interfaces. 13:53859-53867
Publication Year :
2021
Publisher :
American Chemical Society (ACS), 2021.

Abstract

Redox mediators (RMs) have become a significant point in the now-established Li-O2 battery system to reduce the charging overpotential in the oxygen evolution process. Nevertheless, a major inherent barrier of the RM is the redox shuttling between the Li metal anode and mobile RM, resulting in the corrosion of Li and depletion of RM. In this study, taking iodide/triiodide as a model RM, we propose an effective strategy by immersing the Li metal anode in I2 steam to create a 1.5 μm thick surface protective layer. The resultant ionic conductive LiI layer on the Li metal anode can not only suppress Li dendrite growth but also act as a buffer layer between the RM and bare Li. By combining the iodide/triiodide RM with the LiI protective layer, the Li-O2 battery shows low and steady charge voltage plateaus of ∼3.6 V over 70 cycles. Importantly, the symmetrical cell using the LiI-protected Li electrode exhibited small Li plating/stripping overpotentials (∼20 mV, 480 h), far superior to that of the bare Li electrode (∼70 mV, 300 h). The in situ interfacial observation shows that dendrite growth on the Li metal can be effectively suppressed by optimizing the LiI protective layer.

Details

ISSN :
19448252 and 19448244
Volume :
13
Database :
OpenAIRE
Journal :
ACS Applied Materials & Interfaces
Accession number :
edsair.doi...........893f9f9824b7d347951009c4556d20ac