Pretreatment of poplar powder by light bio-oil for preparation of porous carbon materials with excellent electrochemical performance

Abstract

Reasonable pretreatment strategies play a crucial role in enhancing the pore structure and electrochemical performance of porous carbon materials (PCMs). In this paper, the light bio-oil, as one of the by-products of biomass pyrolysis, was proposed to pretreat poplar powder to investigate the influence on the properties of the PCMs obtained under ZnCl2 activation. The Scanning electron microscopy (SEM) analysis showed that the surface morphology of the biomass was seriously destroyed by light bio-oil treatment. And, the relative crystallinity of the biomass increased after the treatment based on the X-ray diffraction (XRD) analysis. Correspondingly, the obtained PCMs with the help of light bio-oil treatment have the better reasonable hierarchical pore structure and electrochemical performances. The specific surface area of PCMs obtained from light bio-oil pretreatment together with ZnCl2 activation at 500 °C reached 2063.8 m2/g. Its specific capacitance reached 306.5 F/g at 0.5 A/g. The symmetric supercapacitor assembled with the corresponding PCMs also exhibited excellent performance. The energy density reached 8.69 Wh kg−1 at 125 W kg−1. After undergoing 10,000 cycle tests, the capacitance retention rate was 98.46 %. This paper can provide some reference significance on the pathway for the preparation of supercapacitor electrode materials from biomass resources.