▎ 摘　　要

Paper-making black liquor lignin carbon nanosheets and multilayer graphene derived from Ni2+ catalytic graphitisation were assembled in block-activated woodceramics to prepare supercapacitor electrode materials (Ni@WE) in an environmentally friendly manner. Na2CO3 activation, Ni-doping, and catalytic graphitisation were completed synchronously, and the natural hierarchical pore structure of wood was partly maintained. During the sintering process, Ni2+ was reduced to Ni nanoparticles and embedded into the carbon template to form the skeleton of Ni@WE. Meanwhile, parts of the lignin were converted into graphitised carbon nanosheets and multilayer graphene, some of them present an orderly arrangement and flocculated form to provide more channels for the storage and transmission of electrons and ions. Cyclic voltammetry (CV), galvanostatic charge-discharge, and electrochemical impedance spectroscopy (EIS) of Ni@WE confirmed that the sample sintered at 1000 degrees C had a specific capacitance of 163.7 F/g at a scanning frequency of 0.2 V/s. Moreover, a higher energy density of 26.2 Wh/kg at the power density of 124.6 W/kg was obtained in an ASC, and 89.37% capacitance remains even after 2000 cycles. (C) 2019 Elsevier B.V. All rights reserved.