Batteries are essential for many devices, from smartphones to electric cars. But most batteries today use lithium, which is expensive, scarce, and harmful to the environment. That’s why researchers are looking for alternatives that are cheaper, more abundant, and more eco-friendly.
One promising option is to use sodium (like the Xubaka bike we’ve covered before) or potassium instead of lithium. These elements are much more common and can be extracted from seawater or salt mines. They also have similar chemical properties to lithium, making them compatible with existing battery technologies.
However, sodium-ion and potassium-ion batteries have a major drawback: they store less energy than lithium-ion batteries. This means they need to be recharged more often or replaced sooner. To overcome this challenge, scientists need to find better materials for the electrodes, which are the parts of the battery that store and release electricity.
A team of researchers from The Tokyo University of Science in Japan has recently made a breakthrough in this area: They have developed a new way to make electrodes from hard carbon, a type of carbon that has no regular structure. By using zinc oxide and calcium carbonate as templates, they were able to create tiny pores in the hard carbon, which increased its capacity to hold sodium or potassium ions.
The researchers tested their new electrodes in real batteries and found that they performed much better than conventional ones. They achieved an energy density of 312 Wh kg–1 for sodium-ion batteries, which is comparable to some lithium-ion batteries. They also showed that their electrodes could work well for potassium-ion batteries, which are even more challenging to develop.
This discovery could pave the way for more efficient and sustainable batteries in the future. It could also help to reduce the dependence on lithium and its environmental impact. The researchers hope that their findings will inspire more research and innovation in this field. To know more about the discovery, check out the original research paper published in Advanced Energy Materials. Authors: Daisuke Igarashi, Yoko Tanaka, Kei Kubota, Ryoichi Tatara, Hayato Maejima, Tomooki Hosaka, Shinichi Komaba.
See below the Xubaka motorcycle by Sodium Cycles, which aims to be powered by a sodium-ion battery.
We published about Xubaka for CES 2021 (virtual CES) and we saw the motorcycle at CES 2022. The sodium-ion battery is still under development at CNRS-backed Tiamat (CNRS: French National Center of Scientific Research). The new type of battery, which was unveiled in 2015 by RS2E as a prototype, is currently not available and now, for the first time, Xubaka units will feature a tailor-made lithium-ion version.