Heteroatom-Doped Pillared Porous Carbon Architectures with Ultrafast Electron and Ion Transport Capabilities under High Mass Loadings for High-Rate Supercapacitors
Yunyun Zhao, Chunxiang Dong, Lizhi Sheng, Zhenpeng Xiao, Lili Jiang, Xinyue Li, Meihui Jiang, Junyou Shi
Abstract
Retaining fast electron and ion transport of electrode materials at high mass loadings holds significant importance to supercapacitors. Carbon-based materials with ultrathin electrodes or small amounts of active materials on the current collectors, that is, active materials with a low mass loading (<1 mg cm–2), have achieved high capacitances and power densities with a fast charging/discharging rate. Yet, the low mass loading leads to low capacitances based on area or the device and, consequently, poor energy. Simultaneously, it cannot be readily scaled to commercial electrodes that have practical levels of mass loading above 10 mg cm–2. Here, we demonstrate N, O, and S self-doped pillared porous carbon architectures (AMJ-3) through the integration of the heteroatom-doping method and architectonic design, which exhibit excellent frequency response with a scan rate up to 7 V s–1 at 1.6 mg cm–2 and 500 mV s–1 at 12 mg cm–2. Furthermore, an ultrafast AMJ-3//AMJ-3 symmetric supercapacitor can be charged/discharged within 0.49 s to deliver both high specific energy of 11 Wh kg–1 and ultrahigh power of 107 kW kg–1 in 1 M Na2SO4. Most importantly, AMJ-3//AMJ-3 symmetric supercapacitor can simultaneously achieve excellent energy density normalized to area (0.21 mWh cm–2) at a high mass loading of 24 mg cm–2.