Hitachi, Ltd. and Hitachi Vehicle Energy, Ltd. have developed a lithium-ion battery with power density of 4,500 W/kg, which is 1.7 times the output of the company’s mass-produced, automotive lithium-ion batteries. Sampling of the new battery will start this fall.
To reduce internal resistance, the battery employs a new manganese cathode and an original Hitachi battery structure. Hitachi said that for the same energy density, a lithium-ion battery has about half the volume and weight of a nickel hydrogen battery, and about one-third the volume and weight of a lead battery.
In 2000, the Hitachi Group developed and mass-produced a lithium-ion battery for automotive applications. A second-generation lithium-ion battery with a power density of 2,600 W/kg is currently being delivered for on-board automotive applications. A total of some 600,000 cells have been delivered, mainly to car manufacturers and railway companies.
Development of a third-generation lithium-ion battery with a power density of 3,000 W/kg has been completed. That battery will go into mass-production in 2010.
The fourth-generation battery set to start sampling this fall is smaller and lighter yet able to provide 4,500W/kg output.