No. 340: The performance of a storage battery is improving rapidly (2/2) (October 31, 2011)

NEC developed a lithium-ion battery with an electrode that employs manganese instead of cobalt: manganese is about twentieth of cobalt in price. Besides the low cost electrode, the company modified the ingredient of the electrolyte and succeeded in achieving better performance. The new lithium-ion battery is hard to generate heat and able to discharge and charge for more than 20,000 times. It has a life of 13 years without problems if it is charged during nighttime when electricity rate is low and used during daytime: The existing lithium-ion battery has a life of 7-8 years. The company plans to lengthen the current life of 13 years to 20 years in five years, and subsequently put it on the market.

In the industrial world, efforts are being made to expand the application of a storage battery to smart grids and smart houses. Japan IBM is implementing the plan to build an eco town in collaboration with the city of Sendai, and Fujitsu submitted a plan to build a smart city to Fukushima Prefecture. Sony is addressing a project to build a large lithium-ion battery. However, a large storage battery with a capacity big enough to be built in the transmission network is still in the development stage. The development of a large storage capacity is vital for the stable supply of electricity generated by renewable energy. Every company concerned has entered a period of tough competition.