Bor Jang, cofounder of Nanotek Instruments in Dayton, Ohio, which makes graphene electrodes for supercapacitors, says the new electrodes may lack energy density. Besides, he says, “a combination of graphene, MnO2, and a conductive polymer or carbon nanotubes might be overkill.”
Others have obtained much higher capacitance numbers with graphene–metal oxide or conductive polymer electrodes. However, Cui says what’s most exciting about the new work is that such a simple dipping technique can enhance capacitance. He says the technique might be used to improve the conductivity of other electrode materials such as sulfur, silicon, and lithium manganese phosphate, thereby enhancing the performance of lithium-ion batteries. Cui and his colleagues are now working on improving battery electrodes using the new method.