Researchers at Bristol have developed high-performance sodium and potassium ion batteries using sustainably sourced cellulose.
Scientists at the Bristol Composites Institute have developed a novel controllable unidirectional ice-templating strategy which can tailor the electrochemical performances of next-generation post-lithium-ion batteries with sustainability and large-scale availability. The paper is published in the journal Advanced Functional Materials.
There is a rapidly increasing demand for sustainable, ethical and low-cost energy-storage. This is due in part to the drive towards developing battery-powered transport systems – mostly replacing petrol and diesel-based engines with electric vehicles – but also for hand-held devices such as mobile phones. Currently these technologies largely rely on lithium-ion batteries.
Batteries have two electrodes and a separator, with what is called an electrolyte between them which carries the charge. There are several problems associated with using lithium for these batteries, including build-up of the metal inside the devices which can lead to short circuits and overheating.
Alternatives to lithium, such as sodium and potassium batteries have not historically performed as well in terms of their rate performance and the ability to use them lots of times. This inferior performance is due to the larger sizes of sodium and potassium ions, and their ability to move through the porous carbon electrodes in the batteries.
Another issue associated with these batteries is they cannot be easily disposed of at end-of-life, as they use materials that are not sustainable. The cost of the materials is also a factor and there is a need to provide cheaper sources of stored energy.