An organic radical battery (ORB) operating at room temperature with lithium metal anode and radical polymer poly (2,2,6,6-tetramethylpiperidinyloxy-4-ylmethacrylate) (PTMA) cathode with a microporous polymer electrolyte based on electrospun poly (vinylidene fluoride-co-hexafluoropropylene) membrane has been demonstrated. The polymer electrolyte with a fully interconnected pore structure, high electrolyte uptake, and high ionic conductivity is found to be suitable for use in PTMA-based ORBs. The cell with a thin cathode of 17 mu m thickness incorporating 40 wt % of PTMA exhibits a discharge capacity of 111 mAh/g at 1 C-rate (0.1 mA/cm(2)) that corresponds to similar to 100% theoretical capacity. Good rate capability is shown by the ORB; thus, a specific capacity of 98 mAh/g is delivered even at the very high 50 C-rate. A stable cycle property is obtained at all C-rates, with the cathode structure remaining intact during cycling. The polymer electrolyte shows good compatibility with the electrodes and leads to a decrease of electrode/electrolyte interfacial resistance with cycling. The study indicates the suitability of microporous, polymer electrolyte-based ORB as a safe, lightweight, environmentally benign, flexible battery with high power-rate capability for varied applications. (C) 2007 The Electrochemical Society.