High-Performance Battery for Premium Class Hybrid Vehicles

Authors

A. Sauer MSc, Dipl.-Ing. M. Lenz, RWTH Aachen University;
Dr.-Ing. F.-W. Speckens, Dr.-Ing. M. Stapelbroek, Dipl.-Ing. J. Ogrzewalla, FEV Europe GmbH, Aachen

Year

2020

Print Info

Fortschritt-Berichte VDI, Reihe 12, Nr. 813

Summary

In addition to the development of fully electric vehicles and 48 V mild hybrid vehicles, another focus is on full hybrid powertrain solutions, especially in the premium vehicle segment. Current developments of hybrid vehicles focus on reducing pollutant and CO₂ emissions in corresponding test cycles (e.g., in Europe, the Worldwide harmonized Light vehicles Test Procedure, WLTP) at minimal additional cost. Special attention is paid to the driver's and passengers' perception of optimal drivability and optimal retrieval of drive power, both essential factors in the decision to buy a premium-class vehicle.
Battery systems for such premium hybrid vehicles must have a long cycle life with an energy capacity of 1 to 2 kWh. Particularly challenging here is the high charging and, above all, discharging rates of up to 50 C with simultaneous installation space restrictions. This power request results in high demands on the battery cells and the module design.
This article presents a new type of modular, high-performance battery system for hybrid vehicles that meets these requirements. The concept is based on a combined central structural element with cooling functions and flexible module format, which can be assembled using conventional methods. The selected cells are based on lithium titanate (LTO) cell chemistry. With the liquid cooling concept presented here, the module design allows a flexible package of batteries so that they fit into limited and, due to their geometry, challenging installation spaces.