This student-run monthly series spotlights the latest research from Stanford, presented by PhD candidates and postdocs. Registration is required, and is free and open to the public.

This month's speakers:

Ajay Ravi, Ph.D. Candidate, Stanford University
"Revealing and Quantifying Carbon Corrosion in Aqueous Manganese-Based Batteries"

Talk Abstract: The MnO₂/Mn²⁺ cathode chemistry represents a promising avenue for high-energy-density and low-cost aqueous batteries. However, its practical application for grid-scale storage is limited by insufficient cycling stability. Extensive reports have highlighted the poor reversibility of MnO₂ deposition and stripping. In this talk, I will reveal an overlooked source of capacity loss under typical operating conditions: corrosion of the carbon current collector. Using gas chromatography, we show that carbon corrosion can account for up to ∼25% of initial capacity losses and can cause thickness losses approaching 200 nm in the first cycle. Corrosion-induced thickness losses are largest under acidic and near-neutral conditions. Corroborating our corrosion measurements, X-ray photoelectron spectroscopy and scanning electron microscopy results indicate the formation of surface oxygen species and carbon fiber degradation after cycling. This work provides a quantitative understanding of carbon corrosion in aqueous batteries that can inform strategies for extending their cycle life.

Speaker's Bio: Ajay Ravi is a rising 3^rd year PhD candidate in Materials Science & Engineering, supervised by Prof. Yi Cui. His research focuses on surface and interfacial science for the development of long-life aqueous batteries. Previously, Ajay received his B.S. in Materials Science & Engineering from Stanford University in 2023.