Soda-can sized thermophotovoltaic battery replacement

A portable cylindrical thermophotovoltaic (TPV) battery replacement is described. This small 8 cm diameter unit is designed to consume fuel at a rate of approximately 200 W and to produce 20 W of DC power. It consists of a cylindrical TPV receiver assembly using simple diffused junction GaSb IR cells along with a novel omega recuperator and a novel doped ceramic matched IR emitter. With a TPV conversion efficiency of 10%, this lightweight TPV cylinder along with a fuel cylinder can have a very high specific energy of approximately 1000 Wh/kg. This specific energy is 6.5 times higher than the specific energy for a Li-ion battery with a similar power rating making this TPV unit very lightweight. The key is the 10% system efficiency. An earlier design for a TPV battery replacement is also reviewed with the key differences in the recuperator, IR emitter, and TPV converter circuit enumerated. The highlighted improvements then lead to the 10% overall system efficiency.