Enabling Fast Charging of High Loading Batteries Via Operando Microscopy Diagnosis of Lithium Plating Limits

While lithium-ion batteries have undergone substantial development, enabling their widespread adoption in consumer electronics, a critical need persists—achieving faster charging even at lower temperatures. This realization is hindered by lithium plating, which reduces capacity and cycle life. A possible strategy involves engineering the electrolyte to improve the ionic transport across/into the graphitic anode. Based on recent studies and simulation results, the traditional carbonate-based electrolyte was replaced with a more promising ether-based electrolyte and tested in our specially designed operando capillary full cells. Here the axial lithiation of graphite could be monitored in real-time and lithium plating precisely correlated to the voltage response. Lithium-ion transport at the face of the electrode was further evaluated with our in-plane imaging setup. The demonstrated performance improvements were then investigated in larger high loading cells at different temperatures and cycling conditions. Our results reveal significantly better charging characteristics for the ether-based electrolyte, not only showing better particle activation but also increasing the capacity (as much as 40%) before the onset of lithium plating. This prompts a compelling inquiry into the roles played by ether driven solid electrolyte interface (SEI) formation and possible co-intercalation processes. How might these mechanisms contribute to the observed enhancements, and what implications could they have for the broader landscape for fast charging batteries. Figure 1