Exploring Discharge Product Distribution in Li-O 2 Batteries

• Published in: Meeting abstracts (Electrochemical Society) Vol. MA2025-01; no. 62; p. 2938
• Main Authors: Brazel, Laurence, De Volder, Michael F. L., Grey, Clare P., Temprano, Israel
• Format: Journal Article
• Language: English
• Published: 11.07.2025
• ISSN: 2151-2043; 2151-2035
• DOI: 10.1149/MA2025-01622938mtgabs

Li-air batteries are a post-Li-ion battery technology which promises extremely high energy densities. Many technological problems must be overcome before they are commercially viable, one of which is limited capacity at high discharge rates. One of the main reasons for this is the slow mass transport of O 2 through the air electrode, resulting in uneven discharge product distribution and low overall utilisation of the air electrode. We have developed novel methodologies to characterise the discharge product distribution throughout the air electrode using scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) and X-ray micro-computed tomography (microCT). Using this methodology, we have characterised the discharge product distribution in Li-air battery air electrodes discharged in a variety of conditions, exploring different discharge rates and electrolyte solvents. The findings suggests the distribution is dependent on a combination of O 2 mass transport and Li 2 O 2 nucleation and growth kinetics. We have developed a continuum model of the Li-air battery air electrode which more accurately captures the Li 2 O 2 morphology, and the distribution of Li 2 O 2 in this simulated electrode matches more closely with our experimentally observed results, when compared to existing models. These results can be used to inform on ideal electrolyte properties to maximise the capacity of Li-air batteries at different discharge conditions by tuning the O 2 mass transport properties and Li 2 O 2 nucleation and growth kinetics. Additionally, air electrode design can be optimised to ensure full utilisation of electrode and maximisation of the specific capacity of the battery. Figure 1