Galvanostatic charge-discharge of a Li-ion battery with Autolab

Significance of the topic

The galvanostatic charge–discharge technique is widely used to characterize lithium-ion batteries, offering insight into capacity retention, redox behavior and polarization effects under differing current rates. Accurate assessment of battery performance at various C-rates is critical for applications ranging from portable electronics to electric vehicles and large-scale energy storage.

Objectives and study overview

This study demonstrates how to perform controlled galvanostatic cycling on a 2.6 Ah Li-ion battery using the Autolab PGSTAT302N with BOOSTER20A. Charge and discharge tests are conducted at 0.1C, 0.2C, 1C and 2C to evaluate the influence of current rates on capacity and potential profiles.

Methodology

– Battery cycled between 3.0 V and 4.2 V under constant current conditions.
– Four C-rates: 0.1C (260 mA, 10 h), 0.2C (520 mA, 5 h), 1C (2.6 A, 1 h), 2C (5.2 A, 0.5 h).
– Potential vs. time data recorded; capacity calculated as C = i·t/3600.
– Relative capacity expressed as percentage of nominal 2.6 Ah capacity.

Instrumentation

– Autolab PGSTAT302N potentiostat/galvanostat
– Autolab BOOSTER20A external booster for high-current operation
– NOVA software for experiment control, data acquisition and capacity calculations
– 2.6 Ah, 3.7 V nominal Li-ion battery as device under test

Main results and discussion

At low currents (0.1C, 0.2C) clear voltage plateaus appear, corresponding to redox transitions of electrode materials and indicating nearly full lithiation/delithiation. As current increases, polarization limits ion intercalation, reducing accessible capacity. Relative capacities observed:

• 0.1C: ~100% of nominal capacity
• 0.5C: ~90%
• 1C: ~60%
• 2C: ~12%

Voltage vs. relative capacity plots illustrate the loss of plateau region and increasing overpotential at higher rates.

Benefits and practical applications

– Provides a straightforward procedure to quantify battery capacity and kinetics under real-world current demands.
– Enables comparison of electrode material performance and evaluation of cell design.
– Offers a reference protocol for quality control and research into fast-charging capabilities.

Future trends and applications

Advances may include integration of temperature control to assess thermal effects, multiphase cycling protocols to simulate real-life usage, coupling with impedance spectroscopy for deeper mechanistic insight, and adaptation to next-generation electrode materials such as silicon or solid-state electrolytes.

Conclusion

This work validates the use of the Autolab PGSTAT302N with BOOSTER20A and NOVA software for comprehensive galvanostatic characterization of Li-ion batteries. The approach yields detailed capacity and voltage profiles across a range of C-rates, aiding in the optimization of battery performance.

References

Metrohm Application Note AN-BAT-002, "Galvanostatic charge-discharge of a Li-ion battery with Autolab," November 2018.