M1: The specifications and requirements for the battery thermal management system (BTMS) have been finalised and handed to WP2 and WP3 leaders (M8)
WP1: Requirements & Specifications
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 with respect to the driving time of an equivalent vehicle with 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 and lifetime of the pack. The battery cells have been selected after an accurate comparison of different parameters of available cells. The battery pack configuration will be composed of 12 modules, each with 15P3S cells, for a total of 540 cells. A concept for the design of the battery cooling system incorporating advanced thermal technologies has been prepared and the final implementation is discussed.
Finally, a concept and validation plan has been identified, with all the necessary virtual simulations and tests to be performed for components, systems and vehicle.
WP2: Component development, testing & modelling
Multi-functional sandwich battery housing.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. The principle design of the battery housing has been successfully established; 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 in order 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.
Ultra-compact cooling module.A new front-end cooling module is under design. It consists of a two heat exchanger layers cooling module composed of an Evaporator/Condenser, a low temperature radiator (LT RAD) and a 600 W single brushless fan. Its first aero-thermal performances were evaluated in the vehicle using CFD (Computational Fluid Dynamics) tool and gave promising results. Inlet Guide vanes have been also designed in order to avoid recirculations phenomena during fast charge.
Cold storage device to optimize cabin comfort while fast charging.The concept of a thermal system using a cold storage device alternating between storage and release modes to address cabin comfort and battery cooling at the same time during fast charge have been evaluated using 1D simulations with Dymola software. During this study, a cold storage device made up of an evaporator immersed in 500 ml of water, which serves as PCM, was used.