Enhanced electrochemical performance of Si-carbon materials from Larch waste by filtration liquefaction residue process

Abstract Super-capacitor has been keeping large scientific interest since it was found. In the meantime, how to clever utilize biomass to improve biomass super-capacitor performance still remains challenge. It is notably concern to fabricate Si-carbon materials by efficient utilization of Larch sawdust, and enhance electrochemical performance of Si-carbon by simple process. Here we show, the Si-carbon material was produced from larch liquefaction via liquefaction-filtration-in situ doping-carbonization process, and the hierarchically porous carbon was prepared from larch residue by liquefaction-filtration-KOH activation-carbonization process. The as-prepared materials exhibited superb electrochemical performance. The larch residue-carbon material has certain electrochemical properties (specific capacitance = 211.4 F/g). As well as, the Si-carbon material with abundant porosity (BET = 284.9 m2/g) reveals a high specific capacitance (254.0 F/g), energy density (90.31 Wh/kg) and power density (177.0 W/kg) at a current density of 0.2 A/g in 1 M KOH electrolyte, as well as a good rate performance and stability (with a capacitance retention above 97% after 3000 cycles), the specific capacitance improved by 10% via further filtration process (from 235.5 F/g). Taking a simple liquefaction filtration process improved the efficiency and electrochemical performance of larch sawdust.