World’s thinnest disposable lithium battery was developed by FDK Corp. that is one of the group companies of Fujitsu, Ltd. The new battery is as thin as 0.42 mm. Using thin film materials, FDK successfully built such a thin lithium battery and, at the same time, lengthened the product life to five years that is more than 1.5 times longer than those of competitive products on the market. It is about 25 mm wide and 25 mm deep that is approximately the same size of a thumb. The company plans to target the market of thin cards for security purposes. For example, the new lithium battery makes it possible to develop a security card with passwords that vary with financial services. Currently, small button-shaped batteries are dominant in the market, but it is hard to make the button-shaped battery thinner. FDK is scheduled to start mass production coming September and achieve sales of 500 million yen by March 2012.