Preparation of activated carbon nanofibers by degradative solvent extraction product from low-rank coal for supercapacitors

摘要

In this study, a low-rank coal was treated by degradative solvent extraction and the mixture of high-molecular weight extracts (Deposits) and polyacrylonitrile (PAN) was used as a precursor for electrospinning. Deposits were pitch-like products and had some outstanding properties, such as high carbon content, low ash content, high aromacity, good thermoplasticity and good solubility in DMF. To improve the spinnability of the precursor, PAN was added into the Deposit. The mixture was fabricated to fibers by electrospinning method. The prepared carbon nanofibers were then activated by CO_2 and directly used as a supercapacitor electrode. The results showed that the specific area was improved from 688 to 1005 m~2 g~(-1) when the mixing ratio of PAN and Deposits was 2:1 compared to pure PAN. The specific capacitance of the Deposit-based carbon nanofibers also increased significantly. The enhanced surface area, pore volume, and the decrease of average fiber diameter made an impact upon the unique electrochemical properties.