Battery impedance spectroscopy

Impedance spectroscopy is one of the most effective methods for characterizing battery deterioration factors, as well as for the component and material development. Impedance analysis in combination with charge-discharge cycles enables an optimization of the battery management system.

The impedance spectrum analyzer TrueData-EIS allows impedance spectroscopy measurement as a stand-alone device or as an integrated component of the battery test station Evaluator-B. With the Evaluator-B the battery can be charged or discharged in a fully automated manner while the impedance spectrum is measured. Examples for typical measurements:

  • Impedance spectrum at 100 %, 80 %, 60 % State of Charge (SOC)
  • Impedance spectrum after 50, 100, 150 ... cycles
  • Impedance spectrum after a stress phase within a driving cycle

The battery behaviour during highly dynamic loads is particularly interesting when evaluating hybrid batteries. The internal resistance of batteries significantly affects the maximum current especially at pulse-shaped loads.

Applications

  • Characterizing deterioration causing factors
  • Component and material optimization
  • Minimizing self-discharging losses
  • Optimization of battery management
  • Measuring and characterizing internal resistance
  • Evaluation of electrolyte losses
  • Increasing durability
  • Manufacturing process control


The impedance spectrometer TrueData-EIS is ideally designed for battery testing. The high DC current range up to 1,000 A and the very small impedances within mΩ range guarantee optimal measurement conditions. The Electrochemical Impedance Spectroscopy (EIS), with a frequency range between 200 µHz and 100 kHz, enables the measurement of the typical impedance spectrum of batteries.

Combined with the multiplex module TrueData-MUX different cells of a battery can be tested at the same time. As a result, the battery management system can be optimized.