April 30th, 2020th

Throughout the 1st year (December 2018 – November 2019) the SELFIE partners focused on the requirements and specifications of the battery thermal management system, as well as on a first preliminary concept design on components and system level. The requirements and specifications at vehicle level have been identified in terms of vehicle performances (max power, max speed, etc.) and driving range, considering the target to remain inside an interval of 60min – 90min more concerning the driving time of an equivalent vehicle with an internal combustion engine for long duration trips of 700-1000 km. Starting from such vehicle requirements, detailed specifications for the battery system have been defined in terms of volume, weight, energy, charging rate, charging power (140 kW) and the lifetime of the pack. After this important milestone, the work could focus on the concept for the design at components and system level, for example, a multi-functional sandwich battery housing (Fig.1). An important part of the SELFIE project is the design and engineering of a battery housing which besides of mechanically supporting the battery cells provides heat storage, heating and cooling capability. It will mainly be made of a sandwich structure consisting of glass-fibre reinforced polymer face sheets and a polymer foam core. The battery cells will be arranged on PCM loaded aluminium foam plates to buffer the heat generated during fast charge cycles to avoid an energy-consuming high power cooling system. Furthermore, cooling plates between the battery rows and in thermal contact with the aluminium foam/PCM plates will remove the heat from the battery pack.

An ultra-compact cooling module and a cold storage device to optimize cabin comfort while fast charging were also designed. 

Outlook on future activities:

The final design of the components of the battery system will be validated by simulation models in terms of functional performance, weight and volume. Furthermore, manufacturability and costs will be taken into account. Once the design is approved and the manufacturing technologies are selected, the manufacturing of prototypes and testing will start. In the meantime, the SELFIE partners are working on the development of an optimal thermal management system control strategy for the battery system. Once the models have been validated, an optimal control strategy for the thermal system will be identified and take into account a compromise between the thermal performance and the energy consumption for different use-cases.