At least according to a group of scientists from Cambridge University, who have announced a major breakthrough in the technology of lithium-oxygen batteries.
Lithium-oxygen batteries show great potential, because theoretically they may be capable of being almost as energy dense as a full tank of gasoline – which is something that currently sounds highly unlikely. They would be appropriate for electric and hybrid vehicles, making them worthy competitors to gasoline-powered cars.
The current lithium-air batteries sadly don't come anywhere near their theoretical potential – the existing market doesn't yet offer suitable porous electrodes with a high enough pore volume to enable frequent charging and emptying of the batteries. Current batteries also get clogged easily, which makes them inefficient, with very short battery life.
Researchers from Cambridge tackled the problem of electrode's small pore volume by creating very thin, one-atom-thick sheets of graphene to produce a highly porous electrode; moreover, lithium peroxide as a proton source was replaced with lithium hydroxide, which created a better chemical durability. Performance of such batteries remained the same even after 2,000 charge-discharge cycles.
Lithium-air batteries will thus likely become our predominant way of storing energy, but there are many obstacles to overcome before they actually become practical and universally used. Judging by efficiency and practicality, lithium-ion batteries are still very much ahead of their lithium-air competitors. Scientists will also need to focus on how the lithium-air batteries work in 'real' air. During the lab trials, scientists tested the processes of charging and discharging of the batteries in pure oxygen, however the air around us is, as we know, full of various other gases, which might in one way or the other compromise the way lithium-air batteries really work.