New battery test systems capable of reproducing safe, continuous and pulsed battery charge/discharge

TECHNOLOGY DESCRIPTION

At present, typical testing protocols include cycle testing that is usually carried out in banks of cells using multichannel testers which can create a different charge and discharge profiles including pulsed inputs and loads. At the same time, performance parameters such as capacity, power output, internal resistance, impedance, open circuit voltage, and discharge time must be monitored and recorded.
To test these new battery applications, IMDEA Energy has built and developed a new battery test system. The system is capable of reproducing safe, continuous and pulsed battery charge/discharge in which more flexibility and intelligence are required to generate the test signal profiles, measure and process the responses of main system parameters like voltage, current, temperature, etc.
Additionally, very flexible configurations are needed to test very different devices and
chemistries. For example, the characteristics of the testing equipment for supercapacitors (high power and low capacity), flow batteries (with recirculation of electrolytes with low power and very high capacity) and Lithium-ion (Li-ion) batteries (with intermediate power and capacity values) are totally different. The battery test plant installed gives a solution to those requirements by implementing a variety of equipment:
-Bench test unit for flow batteries
-Climatic chamber
-Battery cyclers
- Potentiostat

BENEFITS

Conventional testing units are valid in the standard system, but in order to test and analyze new battery systems, (configuration, chemistries, sources integration…) it is necessary to develop procedures for each system.
Compare to other testing facilities the research institute facility offers high flexibility and a wide adaptive measuring and processing capacity. This include:
• High flexibility configuration for different battery chemistries: from devices with conventional stationary electrolytes to recirculating electrolytes, with controlled temperature, flow rate, pressures, humidity, pH, ORP…
• High flexibility in programming complex duty cycles. The test unit can be programmed to simulate the integration with wind and photovoltaic power plants or the driving cycle of an electric vehicle. It is also possible to simulate slow or fast recharging with different types of fluctuations of the power input. Frequency domain analysis can be applied in a wide frequency range (10-3 to 105 Hz). Battery regulation through Battery Management Systems (BMS) can be simulated as well.
• High power for measuring and processing the responses of the tested devices. Normal and transient measurements.
• Knowledge in developing accelerated testing protocols for rapid cycle life and aging evaluation of advanced electrochemical devices.
• Adaptation to testing under flexible configuration in stationary applications coupled to renewable energy sources and for electric vehicles.

LIMITATIONS

No limitations taking into account the following specifications:
-Bench test unit for flow batteries
• Specifically designed for flow batteries or other electrochemical devices in which the electrolyte must be recirculated.
• 2 independent circuits of electrolytes with their respective storage tanks, pumps, valves, piping and instruments for measuring and controlling temperature, flow rates, pressure, pH, conductivity and redox potential.
• 2 x 20 Litre electrolyte tanks and 2 x 1 m3/h (m3/hour recirculation pumps.
• LabView (Laboratory Virtual Instrumentation Engineering Workbench) environment for programming, control, and communication with the battery cyclers.
-Climatic chamber
• Internal net volume over 200 litres, with useful internal dimensions 60 x 54 x 69 cm.
• Operating temperature limits -40ºC to +180ºC.
• Humidity range: 10 – 98%.
• LabView environment for programming, control, and communication with the battery cyclers.
-Battery cyclers
• Two battery cyclers: one for higher power devices (up to 24 kW (Kilowatts)) and the other for lower power (up to 1 kW).
• Higher power cycler includes 3 channels of 40 V (Volts) – 200 A (Amperes) or 120 V – 66 A each. It has the possibility for parallel connection of channels up to 40 V – 600 A or 120 V – 200 A.
• Lower power cycler includes 3 channels of 10 V – 50 A. It has the possibility for parallel connection of channels up to 10 V – 150 A.
• Experiments at a controlled voltage, current, resistance, and power.
• Thermal stress control by thermocouple probes installation.
• LabView environment for programming, control, and communication with the climatic chamber and the flow battery test unit.
-Potentiostat
• Electrochemical techniques at a controlled voltage and controlled current.
• Electrochemical impedance spectroscopy with frequencies from 0.001 to 1000000 Hz (Hertz).
• Booster up to ± 10 V and 10 A.

APPLICATIONS

1) Battery testing equipment.
2) Batteries or other electrochemical devices for stationary applications.
3) Batteries or other electrochemical devices for transport applications, particularly Electric Vehicles.

MATERIALS