Search Results

This paper describes a high-power lithium-ion battery system that has been newly developed for application to hybrid electric vehicles (HEVs). The battery system was designed on the premise of an underfloor location so as to avoid sacrificing interior spaciousness while providing the power output and recharge performance required by the hybrid propulsion system. To meet these requirements, efforts were made to increase the specific power and to reduce the heat generation of the battery to previously unattained levels. As a result, exceptionally high specific power of 1,200 W/kg per cell, battery pack power of 25kW at 20% state of charge (SOC), and high charge/discharge efficiency of more than 95% in the urban driving schedule has been achieved. The battery pack is composed of two box-shaped modules designed with a low height in consideration of underfloor mountability.

This paper presents a lightweight, high-performance Lithium-ion Battery System developed jointly by Nissan Motor Co. and Sony Corp. for electric vehicle (EV) use. Electric vehicles are generally powered by a battery pack consisting of numerous cells connected in a series. Management techniques to elicit the maximum performance of the battery pack are needed, including a function for monitoring individual cells to prevent them from over-discharging. Because of high cell voltage, lithium-ion batteries enable the number of cells in a battery pack to be greatly reduced compared with other types of battery systems. They also allow accurate detection of the battery State of Charge (SOC) based on the battery voltage. These characteristics are conducive to the application of battery pack management technology. These concepts provided the basis for the development of a Lithium-ion Battery System for EV application.