Fabrication of low defect multi-layer graphene using electrochemical intercalation of graphite electrode and its application for graphene/ Al nanocomposites

Low defect multi-layer graphene has been synthesized by electrochemical intercalation of graphite electrode in ammonium sulfate aqueous solution, followed by microwave heating and subsequent ultrasonication. Combination of addition of ethanol as antifoaming agent, alternating current and end-face electrolysis was very effective for high yield production (>75%) of low defect graphene. We applied as-synthesized graphene for graphene/Al composites using stir casting method. Graphene/Al composites with a graphene loading of 0.3% have approximately 40% higher tensile strength (142.2 MPa) and much lower coefficient of thermal expansion (19.8 x 10-6/K) as compared with pure Al (104.0 MPa, 22.7 x 10-6/K).