In Situ Pore Self-Formed Strategy for the Preparation of Sulfur-Doped Hierarchical Porous Carbon Spheres for Supercapacitors

Abstract

Hierarchical porous carbon spheres (HPCSs) have been widely used in energy storage and conversion due to their open framework, high specific surface area and chemical stability. Here, we report a novel and facile method to synthesize porous phenolic resin spheres through an in situ pore self-formed strategy. The phenolic resin spheres can directly transform into sulfur-doped HPCSs by carbonization and activation. The hierarchical porous structure maximizes the specific surface area and facilitates ion diffusion and transport. Combine with the hierarchical porous structure, high specific surface area and suitable S doping content, the HPCSs-based symmetric supercapacitor presents high energy density of 12 Wh kg−1 and outstanding power output capability of 28 kW kg−1. This methodology provides a new way for the preparation of HPCSs and other functional porous carbon spheres with adjustable pore structure and surface properties.