A new polyradical containing polyallene backbone and stable pendant nitroxyl radicals was synthesized using 4-hydroxyl-2,2,6,6-tetramethylpiperidine as starting material. Firstly, a new allenyl ether monomer, 4-allenyloxyl-2,2,6,6-tetramethyl piperidine was prepared by 2 steps. Next, BPO initiated the traditional free radical polymerization of 4-allenyloxyl-2,2,6,6-tetramethyl piperidine at 100 degrees C to obtain the homopolymer, poly(4-allenyloxyl-2,2,6,6-tetramethyl piperidine). Finally, the homopolymer was quantitatively oxidized by H2O2/Na2WO4 center dot 2H(2)O/EDTA at room temperature to yield the final product, poly(4-allenyloxyl-2,2,6,6-tetramethyl piperidine-1-oxyl). Studies on the electrochemical properties of polyradical showed excellent charging/discharging reversibility and stability with a high columbic efficiency of 98%, which suggested that the synthesized polyradical is a promising cathode material for lithium secondary battery. (c) 2008 Elsevier Ltd. All rights reserved.