Controllable synthesis of multilayered porous carbon by ice templating with graphene addition for supercapacitors

In this work, hierarchically multilayered porous carbon (HPC) was designed and prepared by ice template method with the help of graphene. It is found that graphene content has huge influence on the structure of HPC. Under optimal conditions, the HPC can show high surface area of 2078.4 m2 g-1. This porous carbon showed specific capacitance of 201 F g-1 at a current density of 0.5 A g-1 in KOH solution. Additionally, this material displayed excellent cycling performance of 103% initial capacity retained at 10 A g−1 after 10,000 cycles. This porous carbon was used to prepare button supercapacitors with IL electrolyte. This device delivered high energy density of 47 Wh kg-1, corresponding to a power density of 1.5 kW kg−1. More importantly, super cycling performance with 94.4% capacitance retention after 5000 cycles was obtained. Undoubtedly, this work demonstrates that the as-prepared HPC exhibits good application value in the field of supercapacitor electrode materials.