11 June 2009

Prototype Lithium-Sulfur Battery
Lasts 3 Times Longer Than Lithium-Ion

For years we've been promised about super fast charging and longer-lasting batteries that will liberate using of mobile devices, but unfortunately none have materialized onto the market and despite rapid progress in technology, dry cell batteries have not progressed much beyond alkaline battery introduced more than a forty years ago.

Just as you can never be too rich or too pretty, you'll never complain about a battery that lasts too long and despite disappointments with so many 'breakthroughs' in batteries technology over the years there are several new developments could be about to come to the rescue and make batteries more efficient and last longer!

Well, it looks like a research team from the University of Waterloo has done just that. The Waterloo’s team have synthesized a prototype of a lithium-sulphur rechargeable battery that, thanks to its peculiar nanoscale structure, can store three times the power of a conventional lithium-ion battery in the same volume while being significantly lighter and potentially cheaper to manufacture.

When it comes to reducing our carbon footprint, a clean, long-lasting rechargeable battery could have enormous benefits in a wide range of applications, from efficient energy storage to clean transportation.

As with lithium-ion technology, lithium-sulfur batteries store the electrical charge in one electrode during the charging phase and release it to the other during the discharge phase. However, the different atomic structure of the materials involved means the reversible chemical reactions needed are quite different and harder to obtain.

In particular, to gain high performance sulphur needs to remain in intimate contact with a conductor, such as carbon. Nazar's team tackled the issue at the nanoscale level by employing mesoporous carbon, a material that presents a highly uniform pore structure at nanoscale level.

The team assembled a nanostructure of carbon rods separated by empty channels, sulfur was then melted to fill the tiny voids thanks to capillary forces. All the spaces were uniformly filled with sulfur, thus maximizing the surface area in direct contact with carbon and boosting battery efficiency.