Abstract
Tubules of 200 nm outer diameter spinel 
were prepared by thermal decomposition of an aqueous solution containing lithium nitrate and manganese nitrate at 1:2 molar ratio using a nanoporous alumina membrane as a template. After dissolving the template membrane, the resulting nanotubule array of 
was coated with polypyrrole to investigate the galvanostatic charge‐discharge characteristics. The polypyrrole‐coated 
tubule electrodes exhibited higher capacities than the polypyrrole‐coated 
thin‐film electrode prepared under the same conditions, except for the use of the alumina membrane; it was ca. 2.5 times greater at 
and became ca. 12 times greater with an increase in current density to 
. The observed high capacity of the tubule electrode seems to have resulted from two kinds of effects: a decrease in real current density of high specific surface area at the tubule electrode and a decrease in thickness of 
solid phase for 
ions to diffuse through during the charging and discharging reactions.