PNNL

Abstract

Common batteries have difficulty meeting the demands of modern electronic devices, especially when operating at moderate-to-low power levels over extended periods of time. This shortcoming results from the relatively low energy densities found in electrochemical cells. Decreasing the size of the battery exacerbates the problem since the packaging becomes a larger percent of the total volume compared to that of larger conventional cells. Thus, the percent of available space for active materials decreases as the battery size decreases which results in an overall lower energy density. One potential route to solving this problem is to use a power source having a higher energy density. Radioisotopes represent a self-contained energy source capable of delivering modest amounts of power continuously for months-to-years (without recharging) and could possibly fulfill the requirements for a long lasting power supply. Figure 1 demonstrates the difference in power densities of radioisotopes when compared to common battery types and combustible fuels. For a “fair” comparison, a 10% conversion efficiency to electrical power was used for the combustible fuels and radioisotopes.