by Anton Shilov
08/22/2007 | 11:33 PM
Lithium-ion batteries are used almost everywhere nowadays, but the recent recalls of them by top makers like Matsushita/Panasonic, Sony Corp. and Sanyo Corp. indicate that something is wrong with their manufacturing, industry experts believe. The battery specialists claim that fabrication process for those batteries needs to be altered to ensure their safe operation.
“There is a fundamental flaw with the way lithium-ion batteries are currently designed and if the companies genuinely care about safety, they need to completely change their production methods. A lithium-ion battery is quite a dangerous little box of energy,” Masataka Wakihara, of the Tokyo Institute of Technology, who advises the Japanese Government on battery safety, is reported to have said in an interview with The Times.
According to specialists from the Tokyo Institute of Technology, existing lithium-ion batteries submerge the electrodes in an organic solvent that acts as the electrolyte, and separates them with a film of perforated plastic, which is expensive to produce. An alternative, chemical engineers argue, is to encase the electrodes in a solid polymer electrolyte – a structure that might have to be heated slightly to ensure good function.
In fact, Matsushita Battery Industrial (MBI), a division of Matsushita Electric Industrial Co. last year announced battery cells with improved materials that separate cathodes from anodes, however, it is unclear which of the company’s products utilize the new technology and whether it is as robust as proposed by the academics. Sony also announced that it would use a new technology to produce li-ion batteries going forward, but did not unveil its details.
Unfortunately, specialists from the Tokyo Institute of Technology as well as the National Institute of Advanced Industrial Science do not reveal how much more expensive the lithium-ion batteries made with a solid polymer electrolyte are compared to existing ones. Without such information available to smaller producers of accumulators, it is hardly possible to expect them to start using new methods of manufacturing overnight. As a result, manufacturers will test various technologies virtually on end-users.