LiFePO4 olivine (LFP) with few-layer graphene oxide (FLGO) was tested by repeated electrochemical charging/discharging. Here we report on a novel effect that the LFP/FLGO composite, which is electrochemically almost idle in a freshly made state, spontaneously enhances its activity, when the charge/discharge cycling progresses.
Based on electrochemical, IR and Raman studies, we suggest that a gradual in situ reduction of FLGO is responsible for this activation.