Highly anisotropic, multichannel wood carbon with optimized heteroatom doping for supercapacitor and oxygen reduction reaction

Abstract

Rational architectural design of highly active and stable electrochemical materials is desirable for sustainable energy technologies but remains great challenges. Herein, inspired by inherent anisotropic structure for high-efficient ions transport in natural wood, we use basswood as precursor and present a low-tortuosity, multichannel, mesoporous carbon framework for both supercapacitor and oxygen reduction reaction (ORR) applications. With initial heteroatom embedment, followed by ammonia activation, surface functionalities, porous structures and specific surface areas of the wood carbons are simultaneously optimized. Accordingly, the as-prepared materials deliver much enhanced electrochemical performances as self-supported supercapacitor electrodes with remarkable specific capacitances and high energy/power density. Simultaneously, the resultant wood carbons also exhibit superior ORR performances with a half-wave potential of 0.86 V (vs. reversible hydrogen electrode) in alkaline media, in conjunction with superb methanol cross-over tolerance and long-term stability, which then served as suitable and durable air-cathode catalysts for Zn-air battery. The results of this work open up new avenues for facile and rational design of structure-featured carbon materials from earth-abundant biomass for practical energy storage and conversion utilizations.