Bioinspired Highly Crumpled Porous Carbons with Multidirectional Porosity for High Rate Performance Electrochemical Supercapacitors

Abstract

Rational design and facile synthesis of porous carbon materials with optimized porosity are necessary to boost electrochemical performance for energy storage and conversion devices. In this work, we report the fabrication of three-dimensional (3D) highly crumpled porous carbons (HCPCs) inspired by the crumpled structure and functionality of renewable Moringa oleifera leaves by a facile postactivation-free method. The as-resulted HCPCs deliver an interconnected framework, abundant active interfaces, rich heteroatom content, and notably multidirectional porosity for fast ion transport and efficient charge storage. Employed as electrode materials for supercapacitors, the HCPCs exhibit ultrahigh rate capability of capacitance retention over 90% when increasing the current density from 1.0 to 50 A g–1 as well as outstanding cycling stability over 20 000 charge/discharge cycles. Furthermore, the HCPC-based symmetric supercapacitor manifests a high specific energy of 21.6 Wh kg–1, along with excellent structural and electrochemical stability after 20 000 cycles in aqueous medium. This work provides an appealing model of carbon material engineering inspired by the unique structure of natural leaves for fast and high-rate supercapacitors, as well as guidance for rational structural design in extended energy storage and conversion systems.