Abstract: Disclosed herein is the fabrication method of producing nanoporous carbon materials with pore sizes ranging from 2 nanometer to 20 nanometer which can be used as electrode materials for a supercapacitor and an electric double layer capacitors being a kind of supercapacitor. The invention also relates to electric double layer capacitors utilizing these carbon materials as electrodes. The carbon materials presented in the present invention possess regular pores with dimensions ranging in between 2 nm and 20 mm and exhibit high electrical conductivity. These carbon materials shows low equivalent series resistance (ESR) and thus exhibits high charge storage capacity at high charging/discharging current density.

Abstract: A layered structure manganese dioxide (MnO2) of which oxide lattices are in the pattern of pseudo-hexagonal close packing ( . . . AABB . . . ) and has hexagonal P63/mmc space group or orthorhombic Cmcm space group. The present invention also provides a process for producing said layered structure manganese dioxide (MnO2) which comprises heat treating a mixture of an alkali metal compound and a manganese compound at a high temperature. During the process, bismuth compounds or lead compounds may be added in order to stabilize the layered crystal structure of MnO2, or lithium compounds may be added in order to improve the reversibility of charge and discharge. The layered structure MnO2 is suitable for use as a cathode material in lithium rechargeable cells, since it does not transform into a spinel phase during charge and discharge cycling, thus having an excellent charging and discharging reversibility.