in the batteries that may one day power your hybrid or electric car.
We all know that our modern batteries do their thing (charge and discharge) by sending lithium ions back and forth between the anode (where the current comes in) and cathode (where the current goes out). This action is what eventually degrades your electrodes (anodes and cathodes). By improving the materials that bear this beating, scientists aim to increase the amount of energy batteries hold as well as the number of times you can recharge them. Hear about a couple of these efforts after the break.
Tin is one of the materials thought to hold promise as an electrode because it theoretically should hold onto a lot of energy. Unfortunately, it breaks down easily from the passing of the lithium ions. Scientists at the Institute of Chemistry at the Chinese Academy of Sciences think they may have come up with a clever way around this by enclosing nano-sized bits of tin inside elastic hollow carbon spheres, as you can see in the photograph above. The way they accomplish this trick is a little complicated but here is a link to an article in Nanowerk that explains it all in painstaking detail. The result of all this nano-manipulation is an anode with a high specific energy capacity and good cycling performance. To top it all off the researchers believe "their results successfully demonstrate the power of the strategy of using elastic hollow carbon spheres as buffer and container and could be extended to other anode and cathode materials." Exciting stuff.
The other news comes to us from this article in Technology Review about work being carried out at the Argonne National Laboratory. The over-achieving scientists there have made safety improvements, increased the power density and number of charge cycles lithium ion batteries with cobalt oxide electrodes can perform. Not only that, but they have already licensed the technology to a major materials supplier, Toda Kogyo of Japan. Their improvements were achieved by creating a new composite electrode with the cobalt oxide and an electrochemically inactive material. Although this should enable the battery to hold up to 30 percent more energy, the article claims that it is not able to discharge at rates high enough to make it useful for high- power applications such as hybrid and electric cars. Not yet anyway, so the work there continues.
[Source: Nanowerk / Technology Review]