|Voltage||12V 24V 36V 48V|
|Capacity||20ah 40ah 60Ah 80ah|
|Discharge cut-off voltage||customized|
The promise of the lithium-air battery comes from the fact one of the two electrodes, which are usually made of metal or metal oxides, is replaced with air that flows in and out of the battery; a weightless substance is thus substituted for one of the heavy components. The other electrode in such batteries would be pure metallic lithium, a lightweight element.
But that theoretical promise has been limited in practice because of three issues: the need for high voltages for charging, a low efficiency with regard to getting back the amount of energy put in, and low cycle lifetimes, which result from instability in the battery’s oxygen electrode. Researchers have proposed adding lithium iodide in the electrolyte as a way of addressing these problems. But published results have been contradictory, with some studies finding the LiI does improve the cycling life, “while others show that the presence of LiI leads to irreversible reactions and poor battery cycling,” Shao-Horn says.
Previously, “most of the research was focused on organics” to make lithium-air batteries feasible, says Michal Tulodziecki, the paper’s lead author. But most of these organic compounds are not stable, he says, “and that’s why there’s been a great focus on lithium iodide [an inorganic material], which some papers said helps the batteries achieve thousands of cycles. But others say no, it will damage the battery.” In this new study, he says, “we explored in detail how lithium iodide affects the process, with and without water,” a comparison which turned out to be significant.