Next generation lithium- sulphur battery inspired by the human gut read more at here www.spinonews.com/index.php/item/1431-next-generation-lithium-sulphur-battery-inspired-by-the-human-gut

Researchers have developed a prototype of a next-generation lithium-sulphur battery which takes its inspiration in part from the cells lining the human intestine.

The new design overcomes one of technical problem inhibits the commercial development of lithium-sulphur batteries, by preventing the degradation of the battery caused by the loss of material within it.

To collaborate with a Beijing institute of technology, researcher at university of Cambridge developed and tested a lightweight nanostructured material which resembles villi, the finger-like protrusions which line the small intestine.

In the new lithium-sulphur battery, a layer of material with a villi-like structure, made from tiny zinc oxide wires, is placed on the surface of one of the battery's electrodes. This can trap fragments of the active material when they break off, keeping them electrochemically accessible and allowing the material to be reused. 

A typical lithium-ion battery is made of three separate components, an anode (negative electrode), cathode (positive electrode) and an electrolyte in the middle. The most common materials for the anode and cathode are graphite and lithium cobalt oxide, respectively, and both have layered structures. 

Positively-charged lithium ions move back and forth from the cathode, through the electrolyte and into the anode. The crystal structure of the electrode materials determines how much energy can be squeezed into the battery. 

For example, due to the atomic structure of carbon, each carbon atom can take on six lithium ions, limiting the maximum capacity of the battery. 

Sulphur and lithium react differently, via a multi-electron transfer mechanism meaning that elemental Sulphur can offer a much higher theoretical capacity, resulting in a lithium-Sulphur battery with much higher energy density. 

However, when the battery discharges, the lithium and sulphur interact and the ring like Sulphur molecules transform into a chain-like structures, known as a poly-sulphides. As the battery undergoes several charge-discharge cycles, bits of the poly-sulphide can go into the electrolyte, so that over time the battery gradually loses active material. 

The researchers have created a functional layer which lies on top of the cathode and fixes the active material to a conductive framework so the active material can be reused.