Ni2+ catalyzed and N, P co-doped sandwich woodceramics self-supporting electrode prepared from bamboo

Exploring new electrode structure and co-doped biomass carbon materials is considered as an effective approach to develop cheap and efficient energy storage devices. The sandwich structure based on bamboo basic woodceramics self-supporting electrode (BSWE) is obtained from bamboo veneer and bamboo fibers under the catalytic action of Ni2+. Ammonium phosphate ((NH4)3PO4) solution is used as the dopant for hydrothermal activation for co-doping N (nitrogen) and P (phosphorus). The uniform experiment finds that BSWE exhibits the highest specific capacitance in the presence of 12% (NH4)3PO4 solution at an activation temperature of 170 ℃ and activation time of 7 h. BSWE contains an obvious sandwich structure and conserve natural pores of bamboo. The specific surface area is as high as 736.83 m2 g−1, and the pore size is mainly distributed in the range of 0.5–1.0 nm. Ni2+ is partially reduced to elemental Ni and plays a dual role in catalytic graphitization and doping. As well, N and P form a stable structure with woodceramics matrix, resulting in BSWE shows a good electrochemical performance, the energy density reach 12.53 Wh kg−1 as the power density is 500 W kg−1.