Since conventional battery life is limited by the number of times the plates can be reconstituted, this difference portends a longer recharge-cycle lifetime for the plastic batteries. One potential application for polymer batteries is in battery-powered automobiles. Two key measures of a battery's suitability for automotive application are the power density, which determines acceleration and hill-climbing ability, and the energy density, which determines the number of miles that can be driven between charges. Polyacetylene's power density is 12 times that of ordinary lead acid batteries. Its energy density is also higher about 50 watts-hours per kilogram versus 35 for lead acid batteries.
Supporters feel that a polymer battery can be part of the battery-powered car of the future.
Polyacetylene, however, is not an ideal battery material. It degrades in air, is chemically stable only in liquid solutions, and is brittle and not amenable to injection molding methods used for forming plastic parts in production. The University of Pennsylvania team, along with industrial associates licensed to use their technology, searched for conducting polymers of greater structural strength, thermoplasticity, flexibility, and lower costs. Allied Corporation synthesized a new material, polyparaphenylene, a black powder capable of being formed into plates by hot pressing, that could be doped to conduct electricity. Several other potentially suitable plastics were discovered thereafter.