Deciphering the Enigma of Li2CO3 Oxidation Using a Solid-State Li-Air Battery Configuration

Li2CO3 is a ubiquitous byproduct in Li-air (O-2) batteries, and its accumulation on the cathode could be detrimental to the devices. As a result, much efforts have been devoted to investigating its formation and decomposition, in particular, upon cycling of Li-O-2 batteries. At high voltages, Li2CO3 is expected to decompose into CO2 and O-2. However, as recognized from the work of many authors, only CO2, and no O-2, has been identified, and the underlying mechanism remains uncertain so far. Herein, a solid-state Li-O-2 battery (Li vertical bar Li6.4La3Zr1.4Ta0.6O12 vertical bar Au) has been designed to interrogate the Li2CO3 oxidation without interferences from the decomposition of other battery components (organic electrolyte, binder, and carbon cathode) widely applied in conventional Li-O-2 batteries. It is revealed that Li2CO3 can indeed be oxidized to CO2 and O-2 in a more stable solid-state Li-O-2 battery configuration, highlighting the feasibility of reversible operation of Li-O-2 batteries with ambient air as the feeding gas.

Automated summary

In this study, a solid-state Li-O2 battery was designed to investigate the oxidation of Li2CO3, revealing that Li2CO3 can be oxidized to CO2 and O2 in a more stable battery configuration. This highlights the feasibility of reversible operation of Li-O2 batteries with ambient air as the feeding gas.