Zinc-air batteries are metal-air batteries powered by oxidizing zinc with the oxygen from the air. They have high energy densities (as much as five times more energy than lithium-ion batteries) and are more environmentally friendly. Since they are based on abundant zinc, they are potentially much cheaper to produce than the lithium-ion batteries that are used in so many current applications. But because it is difficult and expensive to produce rechargeable versions of these batteries, they have only found limited use in hearing aids, in some film cameras, and in large form to power navigation instruments, oceanographic experiments and railway signals.
The amount of solar energy striking the surface of the earth in two hours is enough to supply all of humankind’s needs for an entire year. For this reason, it is widely thought that solar energy should be our primary source of electricity. If this is to happen, however, there must be cost-effective ways to obtain solar electricity regardless of the time of day, weather, or seasonal changes. Essentially, there must be ways to store the energy from the sun to use it when we need it.
The battery industry is currently dominated by lithium-ion batteries. We have them in our phones and computers. They power electric cars. And they are increasingly being used to store energy generated by solar panels and other renewable energy sources.
Electric cars are generally seen as the way to eliminate or at least dramatically reduce the disastrous effects of personal transportation on the environment. They still constitute only a tiny fraction of the cars on the road, but their popularity and availability is growing.
Energy storage is hot topic because more and more electricity is being generated from renewable sources like solar power and wind power that can’t operate all the time because the sun doesn’t always shine and the wind doesn’t always blow. So we need ways to store surplus energy when it is produced and be able to use it later when it is needed.
Electric cars are still pretty much a novelty in most places, but their numbers are increasing. Electrical utilities around the world are trying to understand what will happen if and when there are millions of them on the road.