Performance enhancement of a lithium ion battery by incorporation of a graphene/polyvinylidene fluoride conductive adhesive layer between the current collector and the active material layer

A conductive adhesive layer (CAL) composed of graphene/polyvinylidene fluoride (PVdF) composite is applied between a current collector and an active material layer to enhance the electrochemical performance of lithium ion battery anodes. Graphene content in the CAL varies in the range of 0–3 wt% relative to PVdF. The CAL significantly improves the cyclic performance of both graphite and silicon/graphite electrodes by increasing the adhesion strength of the electrodes. An increase in graphene content increases electronic conductivity but decreases lithium ion transfer of the CAL film. Therefore, a CAL containing a relatively small amount of graphene (1 wt%) is more favorable to highly conductive graphite electrodes, whereas a CAL containing 2 or 3 wt% graphene shows better electrochemical performance in the case of relatively low conductive silicon/graphite electrodes. ► A graphene/PVdF conductive adhesive layer was applied between Cu foil and the electrode. ► The conductive adhesive layer significantly enhanced C and Si/C anode performance. ► Incorporating graphene increases electronic conductivity, but decreases ion transfer. ► A small amount of graphene (1 wt%) in the layer is favorable for graphite electrodes. ► The silicon/graphite electrodes show the best performance with 2 wt% graphene/PVdF.