Polyacrylonitrile Alcoholysis and Freeze-Expanded Assistive Synthesis of Porous Carbon for High Rate Supercapacitors and Zinc-Ion Hybrid Capacitors.

Although energy storage devices have made great progress in recent years, their electrode materials still face some problems, such as the lack of high-power and high rate performance in lithium battery materials, and poor energy density in capacitor materials. Here, we utilizes polyacrylonitrile (PAN) alcoholysis derivatives as a carbon source to prepare hierarchical porous carbon with a high specific surface area, and employ freeze-expansion method to increase pore size and improve its high magnification performance. The final hierarchical porous carbon material has high specific surface area (2941 m g) and rich N/O doping. The porou carbon applied in supercapacitors exhibits high-rate performance (200.5 F g at 100 A g), high energy density (12.61 Wh kg at 150 W kg) and excellent stability in symmetric supercapacitors. Furthermore, it owns high energy density (120.9 Wh kg at 160 W kg-1) in a zinc-ion hybrid capacitors. The excellent electrochemical performance is further demonstrated by in situ electrochemical quartz crystal microbalance and ex situ characterizations. The PAN alcoholysis and freeze-expanded methes provides a novel strategies for the preparing of hierarchical porous carbon based on PAN, and a new insights to expand the pore size of porous carbon.