Graphene-based integrated electrodes for flexible lithium ion batteries

We have prepared flexible free-standing electrodes with anode and cathode active materials deposited on a highly conductive graphene membrane by a two-step filtration method. Compared with conventional electrodes using metal as current collectors, these electrodes have displayed stronger adhesion, superior electrochemical performance, higher energy density, and better flexibility. A full lithium ion battery assembled by adopting these graphene-based electrodes has showed high rate capability and long cyclic life. We have also assembled a thin, lightweight, and flexible lithium ion battery with poly-(dimethyl siloxane) sheets as packaging material to light a red light-emitting diode. This flexible battery can be easily bent without structural failure or performance loss and operated well under a bent state. The fabrication process of these graphene-based integrated electrodes only has two filtration steps; thus it is easy to scale up. These results suggest great potential for these graphene-based flexible batteries in lightweight, bendable, and wearable electronic devices.