PRODUCTION OF CARBON FIBER FELT

摘要

PROBLEM TO BE SOLVED: To obtain carbon fiber felt useful as an electrode for sodium-sulfur battery by treating a precursor felt using a heat-modified polyacrylonitrile-based flame-resistant fiber as a main raw material with a needle punch and baking the treated felt at high temperature in inert atmosphere. SOLUTION: A heat-modified polyacrylonitrile-based flame-resistant fiber obtained by heat-treating a polyacrylonitrile-based fiber in active atmosphere such as oxygen at 200-300 deg.C for 10-150 min and having >=4 wt.% and <7 wt.% oxygen content is used as a main raw material to form a precursor felt. Then, the precursor felt is treated with needle punch and then baked at >=1,200 deg.C high temperature under inert atmosphere without carrying out further flameproofing treatment to provide the objective carbon fiber felt having <=0.3 Ω.cm volume resistivity in thickness direction and useful as an electrode material.