The battery is safe, thin, flexible and large in area, MIESC said. It will be exhibited at the 1st Int’l Rechargeable Battery Expo, which will take place from March 3 to 5, 2010, in Tokyo.
The positive electrode layer, electrolyte layer and negative electrode layer of the lithium-ion battery are made by roll-to-roll processes. No separator is used between layers.
The positive electrode is made with LiFePO4 and a carbon complex while the negative electrode is made with Li4Ti5O12 and a complex of graphite, silicon, etc. A film made of a polymer material using a cross-linked polyethylene oxide is used for the electrolyte.
The polymer material is not in a gel state but in a solid state, and the battery does not use an organic electrolyte, which is flammable, ensuring high safety.
The A6-size lithium-ion battery is 450μm in thickness. Its initial capacity is 45mAh. When half of the capacity is discharged, its voltage is 1.8V. The discharge rate can be changed between 0.02C and 1.0C.
Existing all-solid lithium polymer storage batteries can hardly be used at a room temperature or below. But the new battery can be used even at a temperature from 0 to 25°C, MIESC said. The charge-discharge cycle is more than 100 and is still being evaluated, it said.