Toshiba Corp showcased the lithium-ion (Li-ion) rechargeable battery pack used for Mitsubishi Motors Corp's "i-MiEV M" electric vehicle (EV) at Smart City Week 2011.
SmartCity Week 2011 is a trade show that took place from Oct 26 to 28, 2011, in Yokohama, Japan.
The average voltage and capacity of the i-MiEV M's battery pack are 270V and about 10.5kWh, respectively, while those of the i-MiEV's battery pack are 330V and 16kWh. The chassis of the i-MiEV M's battery pack is the same as the i-MiEV's battery pack.
The i-MiEV M's battery pack is equipped with battery modules whose average voltage is 27.6V (18 to 32.4V) and capacity is 40Ah. The module measures 359 x 187 x 124mm and weighs 15kg.
The battery module contains 24 units of Toshiba's 20Ah cell (2 parallel x 12 series). The voltage of each cell is 1.5 to 2.7V, and its energy density per volume is 176Wh/L. The cell features excellent low-temperature properties and cycle characteristics and is suited for rapid charging because lithium titanate is used as its negative-electrode material.
The battery pack contains 10 battery modules, but one of them has 18 cells (2 parallel x 9 series) and an average voltage of 20.7V. As a result, the number of cells used for the battery pack is 234 in total.