Graphene with sodium could make better batteries
Graphene doped with sodium can be a key player in making cheap batteries and spintronic devices, EPFL scientists discover. "Lithium is becoming a critical material as it is used extensively in cell-phones and car batteries, while, in principle, sodium could be a much cheaper, more abundant alternative," says Ferenc Simon, a visiting scientist in the group of László Forró at EPFL. "This motivated our quest for a new battery architecture: sodium doped graphene." Graphite doped with lithium atoms, is one of the most common anode material in batteries, and won the 2019 Nobel prize in Chemistry. But the increasing use of lithium can lead to a shortage. On the other hand, sodium is the 6th most abundant element on Earth, while lithium is just 25th. Plus, sodium is available from various sources including rock salt or sea water. However, a major obstacle for using sodium batteries is the fact that graphite can only swell about one tenth of that with lithium, which gives a reduced charge storage capacity and a shorter battery life time.
