Dec 1, 1997
The growth in the use of mobile phones and portable computers is placing new demands on battery technology, but a new type of lithium battery could solve many of these problems.
Lead and nickel-cadmium batteries are still the most common type of battery, but lithium is becoming more popular with power-hungry users.
Lithium can store large voltages, is light, and can be quickly recharged. Unfortunately, lithium batteries can also ignite if they short circuit. Moreover, lithuim batteries suffer the 'memory-effect', where repeated recharge cycles decrease the lifetime of the battery and the charge stored.
As electrical equipment becomes smaller and lighter, more demands are made on batteries. Most cylindrical batteries make use of sheet-shaped electrodes rolled into a cylinder. This leads to technical manufacturing difficulties when designing small high-power batteries, especially for cameras. In these situations, a thick coating is used on both sides of the electrode sheet to increase voltage capacity, which in turn makes it difficult to roll the sheet up.
Hiroshi Fujimoto and Yasuo Aotsuka from Fuji Photo Film Company in Japan have patented a new type of battery which has better properties than those available at present. Patent 5683834 refers to a type of lithium battery which has coatings of different thickness. The inner coating is thinner than the outer one, making it easier to roll up into a cylinder. Tests carried out by the researchers as part of their Patent claim sound very encouraging for users looking for better batteries.