The influence of cathode thickness on the electrochemical performance of an organic radical battery (ORB) with the radical polymer poly(2,2,6,6-tetramethylpiperidinyloxy-4-yl methacrylate) (PTMA) as the cathode active material is presented. The ORB consists of lithium metal anode and PTMA cathode with an active material content of 40 wt.%. An increase in cathode thickness results in a decrease in specific capacity and discharge voltage of the cell and an increase in electrode/electrolyte interfacial resistance. The best performance is achieved with a thin cathode of 17 mu m that shows nearly 100% utilization of the active material(similar to 111 mAh/g) at current densities up to 1.0 mA/cm(2). The cell exhibits excellent high-rate capability and cycle characteristics with a stable impedance behavior and an intact cathode structure on cycling. The results demonstrate that high performance can be achieved from the non-conductive PTMA cathode with higher active material content by using a thin and properly prepared cathode consisting of a uniform, nanometer range coating of the polymer layer on the conductive carbon particles. (C) 2007 Elsevier B.V. All rights reserved.