Capacity recovery by transient voltage pulse in silicon-anode batteries.

Abstract

In the quest for high-capacity battery electrodes, addressing capacity loss attributed to isolated active materials remains a challenge. We developed an approach to substantially recover the isolated active materials in silicon electrodes and used a voltage pulse to reconnect the isolated lithium-silicon (Li<i>_x</i>Si) particles back to the conductive network. Using a 5-second pulse, we achieved >30% of capacity recovery in both Li-Si and Si-lithium iron phosphate (Si-LFP) batteries. The recovered capacity sustains and replicates through multiple pulses, providing a constant capacity advantage. We validated the recovery mechanism as the movement of the neutral isolated Li<i>_x</i>Si particles under a localized nonuniform electric field, a phenomenon known as dielectrophoresis.