Exfoliated graphite (EG) is proposed as an electrode material for solid-state electrochemical capacitors. The EG-based capacitors assembled with a solid electrolyte of polyethylene oxide-ethylene carbonate-propylene carbonate-LiClO4 show high specific capacitance in the range of 0.74-0.98 mF/cm(2). The capacitors also show excellent cyclability. The response time is very short and is of the order of milliseconds. (C) 2004 The Electrochemical Society.