Probing Degradation in Lithium Ion Batteries with On-Chip Electrochemistry Mass Spectrometry
On-chip EC-MS enables fully quantified, time-resolved detection of gases from operating lithium-ion batteries — revealing oxygen evolution from NMC cathodes, SEI formation across electrolytes, and the first direct evidence of CO₂ reduction to ethylene. The technique decouples parasitic reactions that drive capacity fade, providing a tool to validate and guide battery lifetime models.