Lithium air batteries based on protected lithium electrodes

Abstract

The last major advance in portable electrochemical energy storage was the introduction of Li-ion chemistry by Sony in 1991. Since that time battery manufacturers have been relentless in pursuing incremental improvements to Li-ion technology. Still, there are fundamental limits to any battery chemistry and Li-ion technology is clearly maturing. In pursuit of the next battery breakthrough, a number of researchers are exploring the Li/O2 couple, due largely to its extremely high theoretical energy density and the low cost of the oxygen electrode. However, in order to realize those gains, the Li/O2 battery will need to utilize ambient air, and this presents a major technical hurdle as ambient moisture will attack and rapidly corrode the lithium metal electrode. Fortunately, the invention of the protected lithium electrode (PLE) by PolyPlus solves this problem and enables the practical construction of both primary and secondary lithium air batteries. In this chapter we highlight the advances and challenges in aqueous and nonaqueous lithium air battery technology. Notably, external testing of PolyPlus 10 Ah primary lithium air cells has confirmed specific energies in excess of 800 Wh/kg.