A recent letter “How Green Are Electric Vehicles?” [April 26, Xpress] outlines the high cost of extracting lithium and other rare earth metals for electric vehicles. Yes, there are problems. But there is also hope — worldwide research to develop a battery made from commonly available materials, one that is economical, that recharges quickly and does not overheat.
Best candidates now for EVs and possibly for small appliances and phones are the graphene aluminum-ion battery, the potassium-ion battery and the sodium-ion battery. Other emerging battery technologies include the calcium-ion battery, the molten-salt battery, a “nano-flow” battery and one based on sodium sulphur. None of these use lithium.
Some of these are already in use for heavy construction and mining vehicles. And some will store electricity when wind and sunlight subside. For this, there is also the Newton battery, which uses excess electricity to haul weights high into the air and lower them slowly to run generators when needed. And “pumped water” uphill-downhill has been used for decades but is now being set up worldwide.
Let’s not despair. There are many brilliant minds in companies, universities and scientific agencies working diligently to bring us a new generation of batteries. It’s a grand and fascinating contest to see which technology will prevail.
— Tobias Van Buren
Asheville and Mount Pleasant, S.C.