DISPERSED POLYPYRROLE LATEX AS A CATHODE MATERIAL FOR ALL-SOLID-STATELITHIUM BATTERIES

Fine bare polypyrrole latex (200 nm sized) was obtained by improved sy nthesis conditions. This new electronically conducting electroactive m aterial was dispersed in a polyoxyethylene solid salt solution and use d as a battery cathode together with a polymer electrolyte film and a lithium sheet in a three-layered system. The resulting battery behaves very well at low current densities though an incomplete dispersion of the latex has been seen from studies on symmetrical cells (using late x composite for both electrodes). A self-discharge problem for the lit hium cells arose only before the first discharge and during subsequent charge processes. a previously described theoretical model was used t o estimate the ionic diffusion coefficient within the polypyrrole part icles. The very low value - 10(-13) cm(2).s(-1) - obtained explains th e poor performances of this material at moderate current densities.