Are there any lithium battery alternatives?

Lithium-ion batteries power our phones, our computers and, increasingly, our electric vehicles. There are also plans to power our green energy future using wind turbines and solar panels, but that will, in turn, require enormous battery cells to store said electricity for when it is needed.

All of this means that we must continue to mine lithium, but there is no guarantee that we’ll be able to find enough raw material to keep up with demand. Unfortunately, there isn’t going to be a single solution to the problem of how to replace lithium-ion batteries, which is why people have been dreaming up all sorts of variations on the format, to solve the world’s energy storage needs.

Salt

Lithium’s close chemical cousin, sodium, has been the basis for research into new batteries for years now. One half of sodium chloride, or table salt, it sits in the square below lithium on the periodic table, also in group 1, but weightier. While having almost the same chemistry as lithium, it has none of the environmental baggage or geographical limitations, but that doesn’t make it an automatic solution.

Magnesium

Lithium and sodium are both good battery ingredients. However, their ions can only carry an electrical charge of +1. Why not use an ion that can carry a greater charge – like magnesium, with its +2 charge? Several research teams are working on just this. It is early days, but magnesium could one day be the basis of batteries more powerful and safer than those made with lithium or sodium.

Seawater

A major selling point of sodium batteries is that they can be made from a plentiful resource, salt. And what better place to find salt than in seawater? This is why Stefano Passerini’s team at the Karlsruhe Institute of Technology in Germany has developed a prototype battery based on seawater, with the sodium that is naturally dissolved in it carrying the charge. Passerini says he already has keen interest from investors in South Korea.

Glass batteries

Maria Helena Braga at the University of Porto in Portugal has been working on an unusual battery with John Goodenough, the Nobel prizewinning inventor of the li-ion battery. The key component is the electrolyte, which is made of glass spiked with sodium ions, which can travel through it. Every material needed is easy to source. “It’s the most eco-friendly cell you can find,” says Braga.

The battery apparently has extraordinary properties: Braga says it can outperform lithium-based batteries; the one in her office has been powering an LED for five years. Others are having trouble replicating the device. Still, with backing from the likes of Goodenough, this is one battery to watch.

Fuel cells

Think of fuel cells as batteries that you charge by adding fuel rather than plugging them into the mains. John Andrews at RMIT University in Melbourne, Australia, has developed one that splits protons from water, which are then stored inside the battery. To release this power, oxygen from air is fed through the machine, which combines with the protons to produce water and electricity. “It’s a very neat principle,” says Andrews. “The challenge is to make it work in a practical device.”

Liquid batteries

Otherwise known as flow batteries, these work on a similar principle to regular batteries, but all the components are dissolved in liquids. Chemist Lee Cronin at the University of Glasgow, UK, and his team have developed one such battery based on an enormous tungsten-containing molecule. The advantage is that a charged-up liquid battery could be pumped into an electric car quickly, much as petrol is today. The main barrier at the moment is that all that electrical charge makes the liquid electrolyte sticky and therefore difficult to pump.