An all graphene battery is disclosed. The battery is designed into a form of a belt and can charge multiple portable electric devices simultaneously. The battery has a graphene based anode, a graphene composite based cathode. The electrolyte of the battery is gel like functionalized graphene oxide. The device of this disclosure may use thermoelectric effect to charge itself. The battery of this disclosure is safe, and has a high capacity, high energy density and long life time. The battery includes no liquids and is light weighted.