Battery cell integrated sensors and actuators

Topic

Flexible absolute pressure sensor with polyimide cover.
Flexible ceramic temperature sensor embedded in polyimide foils.
Flexible sensor-actuator module with integrated electronics and communication).

Fraunhofer IKTS is developing technologies for a cell-integrated, coupled multisensor and temperature control module for use in lithium-ion battery cells. These modules can determine in-situ temperature and pressure and optionally cell voltage and allow cooling or heating based on the determined parameters. As a result, the current power and safety reserves of lithium batteries can be significantly increased compared to the prior art. The additionally usable energy and power reserves lead to the optimized utilization of cells and entire modules and thus to the increased performance of a complete powertrain of electric vehicles.

Particularly in the context of electromobility applications, the existing security requirements are particularly high, with which measuring data from the inside of the cell is a particular advantage, since they allow early detection of cell degradation and errors. In conjunction with a corresponding battery management system, defective cells can be detected in good time and appropriate changes initiated.
 

Technische charachteristics

 

Sensory solutions

  • Flexible PTC-based Temperature sensors for temperature range -40 – 80°C
    Flexible Ag/C – pressure sensors for pressure range -1 – 3 bar

     

Actuator solutions

  • Battery cell integrated resistance heater (0 – 20 Watt)
    Battery cell integrated PCM-based cooling (70 Wh/kg)

     

Encapsulation

  • Quasi-hermetic encapsulation technologies for sensors within battery cell
     

Electronics and communications

  • Battery cell integrated Signal conditioning und Actuator control via µController
    Communication to BMS via battery terminals (Power-Line-Communication)
Embedded heating element for the start-up at low temperatures

Services offered
 

  • Customer specific development of battery cell integrated sensor and actor solutions (temperature, pressure, voltage, Heating…)
    Development of PCM-based cooling strategies
    Services for development of battery cell specific encapsulation strategies