Gut instinct drives battery boost

A UK-China team of scientists are developing a new prototype battery inspired by the structure of the human intestine.

I've said this before - a team from Harvard are exploring the use of a compound similar to one found in rhubarb for improving the prospects of flow batteries as a large scale energy storage solution - it's curious where inspiration comes from sometimes.

The type of battery the UK-China team are developing is lithium-sulphur. Theoretically this could have 5 times the energy density of today's common lithium-ion technology.

In the human intestine, small finger-like protruding structures called "villi" help to increase the surface area for the absorption of nutrients.

In the new lithium-sulphur technology, the researchers are using a thin layer of nano-sized structures that resemble villi, made of zinc-oxide wires.

As batteries undergo charge-discharge cycles, they physically wear out with the battery losing the active material which is used for the flow of electricity.

The new layer helps to capture some of the pieces which break off and retain them for future use, improving the life of the battery.

The lead author on the research, Cambridge PhD student Teng Zhao, said "This is the first time a chemically functional layer with a well-organised nano-architecture has been proposed to trap and reuse the dissolved active materials during battery charging and discharging. 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."

The technology is still in the proof-of-principle stage, with commercially viable technology years away.

Furthermore, while the life-time of the battery has been improved, it still can not go through as many charge-discharge cycles as a lithium-ion battery.

The increase in energy density appears to cancel out the benefit of a lower number of charge-discharge cycles.

So the team still have some work to do!

The researchers say that, if hurdles to commercial development can be overcome, lithium-sulphur batteries could have five times the energy density of the lithium-ion batteries used in smartphones and other electronics.