Scientists in the UK have developed a prototype lithium-sulfur battery after being inspired by the cells in the human intestine.
Researchers from the University of Cambridge claim to have found a way to prevent the dissolution and diffusion of polysulfide in liquid organic electrolytes — a key issue when looking to commercially develop lithium-sulfur batteries.
The results were reported in the journal Advanced Functional Materials.
The researchers, based at the university’s Department of Materials Science and Metallurgy, collaborated with the Beijing Institute of Technology to trap and re-utilise the polysulfide without hampering lithium ion conductivity.
To do this the team designed a brush-like interlayer consisting of zinc oxide (ZnO) nanowires and interconnected conductive frameworks.
The layer of material, with a villi-like structure (the finger-like protrusions that line the small intestine), was placed on the battery’s cathode to trap fragments of polysulphide when they break off during cycling.
This allows the battery to keep the bits electrochemically accessible during cycles to be reused later.
“It’s a tiny thing, this layer, but it’s important,” said study co-author Dr Paul Coxon from Cambridge’s Department of Materials Science and Metallurgy (DMSM).
“This gets us a long way through the bottleneck which is preventing the development of better batteries.”
The concept was trialled using commercially available nickel foam for support, which was replaced by a lightweight carbon fibre mat to reduce the battery’s overall weight following successful results.
The study’s lead author Teng Zhao, a PhD student from the DMSM, said this was the first time such a development had been proposed.
He added: “By taking our inspiration from the natural world, we were able to come up with a solution that we hope will accelerate the development of next-generation batteries.”
However, a commercially available battery using the technology is still years away, with work to increase the battery’s cycle life so it compares to lithium-ion underway, say the scientists.