Quantifying lithium loss in amorphous silicon thin-film anodes via titration-gas chromatography

Silicon with a high theoretical capacity (3,579 mAh/g) is promising anode candidate for lithium-ion batteries. However, commercialization still impeded by low Coulombic efficiency, caused solid electrolyte interphase (SEI) formation and trapped lithium (Li)-silicon (Si) alloy during repeated volume change. Quantifying losses from each factor crucial to formulate rational design strategies further improvement. In this work, titration-gas chromatography cryogenic transmission electron microscopy are applied characterize the evolution of Li-Si SEI growth in silicon thin-film anode. It found that continuous dominant inventory loss cycling, only marginal increase alloy. This study offers quantitative approach differentiate Li through anode, providing unique insights into identifying critical bottlenecks developing Si anodes.