MESOPHASE PITCH-BASED ACTIVATED CARBON FIBER AND ELECTRIC DOUBLE LAYER CAPACITOR USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an electric double layer capacitor capable of expressing a high service capacity when used as an electrode material by crushing and treating to activate with an alkali mesophase pitch-based carbon fibers produced by carbonizing mesophase pitch-based and infusibilized fibers at a specific temperature. SOLUTION: This mesophase pitch-based activated carbon fibers are produced by crushing mesophase pitch-based carbon fibers produced by carbonizing mesophase pitch-based infusibilized fibers or after the infusibilization at 350-1000 deg.C, preferably 350-800 deg.C into 5-50 μm, preferably 10-30 μm average particle size, successively treating to activate the product with an alkali. The electric double layer capacitor is obtained by using the activated carbon fibers. Preferably, both of pores A having 0.4-1.5 μm pore radius measured by the MP method using nitrogen absorption and pores B having 3.5-6 nm pore radius measured by a mercury porosimeter are present in the activated carbon fibers, and a ratio Bv/Av as the pore volume Bv of the pores B to the pore volume Av of the pores A, is 0.01-0.25.