凯发

I will present that graphene flakes were produced at large scale by electrochemical exfoliation of graphite and further used by electrochemical ways. Tunable sizes, layers, defects, pores and hybridization of graphene could be synthesized via electrochemical approaches. Graphene and its hybrids exhibited high performances in supercapacitor, batteries and electrocatalysis,1-5 as shown in Figure 1. Large literal sheets of 1-3 layer graphene flakes were used to fabricate flexible and free-standing graphene films with high thermal diffusivity, capacity and electromagnetic shielding. Small graphene microsheets produced in tons from natural microcrystalline graphite exhibited wonderful dispersion in various solvents and highly reversible specific capacity as a battery anode material. Graphene flakes were proved to survive annealing in strong basic conditions and stimulate the activation of cellulose or pitch to obtain hierarchical porous graphene-carbon materials. In addition, graphene integrating carbon fiber and hierarchical porous carbon formed robust flexible “carbon-concrete” supercapacitor film, which shows the potential of integrating energy storage and car body. The porous graphene-carbon-based supercapacitors reach 200 F/g (3.5V) in ionic liquid and high energy density of >60 Wh/kg at high rate. In addition, it could be used as cathode of Li-S batteries with >99% coulombic efficiency and 1000-cycle stability. Isolated iron atoms embreded in porous graphene nanomeshes-curved carbon enhanced oxygen reduction electrocatalytic activity that is superior to Pt/C. Electrochemical approach for graphene materials is being commercialized with a big future. This work was  supported by by funds of National Natural Science Foundation of China (21373255, 21503259, 51502320, U1662102) and 100 Talent Program of CAS (2015YCR001).

Figure 1. Images of electrochemically exfoliated graphene flakes with controllable sheet size, pores,  dispersion and casting and isolated Fe atoms loading.