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. (C) 2012 Elsevier B.V. All rights reserved.