Work Package 5: Longer Battery Life

(Updated: December 2018)

OBJECTIVES

Design thermal management and investigate load management strategies for homogeneous cell ageing within the battery pack in order to extend the lifetime of the battery.

PARTNERS: TUM(Lead), VITO, CEA, Voltia

APPROACH

  • Development of passive heat management, implementing phase change materials (PCM).
  • Development of active heat management implementing an innovative & efficient heat pump and coupling with passive heat management.
  • Development and implementation of optimal load management algorithms for balancing circuits and battery reconfiguration topologies.

RESULTS SO FAR

  • During constant current discharge, thermal discrepancy objective is achieved (<1°C between 50 cells) using PCM.
  • Heat pump simulation showed that, the best configuration so far is represented by a double stage heat pump, using R134a as a refrigerant fluid and a phase separator.
  • Coupled thermal and electrical cell model was developed. Voltage errors within 90%-10% SOC range are under 50mV for dynamic profiles.
  • First simulation of temperature control with non-dissipative balancing show a reduction of the temperature gradient in a cell stack from 4.3°C to 1.9°C.