Electric Double Layer Capacitance of Highly Porous Carbon Derived from Lithium Metal and Polytetrafluoroethylene

Abstract
Highly porous carbon material was prepared from defluorination of polytetrafluoroethylene (PTFE) with lithium metal, and its electric double layer capacitance was measured in 1.0 M aqueous electrolyte. The solid-solid reaction product of PTFE film with Li foil had micro/nano domain structure consisting of a one-dimensional carbon chain (carbynelike structure) and LiF. After cross-linking of the carbon chain and condensation of LiF in the reaction product, highly porous carbon containing micropore and meso/macropore was obtained by removal of fine LiF particles with dilute HCl solution. This porous carbon derived from PTFE and Li (PCPTFE) showed higher capacitance (Brunauer-Emmett-Teller, BET, surface area 1045 m2 g-1, capacitance 199 F g-1) than activated carbon fiber with almost the same BET surface area (1084 m2 g-1, 134 F g-1). The higher capacitance of PCPTFE can be related to the surface conditions, the matrix carbon structure, and, especially, the pore structure of PCPTFE. © 2000 The Electrochemical Society. All rights reserved.