How to Do GITT Test by Using Langtian Equipment
1. What is GITT?
Galvanostatic Intermittent Titration Technique (GITT) is a powerful electrochemical method for analyzing lithium-ion diffusion and electrode kinetics. It helps researchers understand how ions move within battery materials during charge and discharge processes.
2. Why Choose Langtian Equipment for GITT Testing?
Langtian battery testing systems are equipped with precise control and flexible programming functions, which make them ideal for GITT experiments.
- High-precision current and voltage control (±0.05% accuracy)
- Fully programmable test sequences supporting current pulses and rest steps
- Automatic data recording and export
- Temperature monitoring and protection
- Intuitive software interface for test setup and result visualization
3. How to Do GITT Testing
3.1 Test Principle
During a GITT test, a constant current (I) is applied for a short period of time (t) to charge or discharge the cell. Then, the current is cut off, and the cell is allowed to relax under open-circuit conditions while the voltage change is recorded.
For example, the battery can be charged at 0.2 C constant current for 10 minutes, followed by a 1-hour rest period to reach equilibrium. This charge–rest cycle continues until the upper cutoff voltage is reached. The discharge process follows the same pattern.
3.2 Equipment Connection
1. Connect positive and negative terminals properly.
2. Ensure stable contact and no loose wiring.
3. If temperature control is available, set 25 ± 1 °C for the environment.
3.3 Charging Process Configuration
| Step | Mode | Current (mA) | Upper Voltage (mV) | Time | Rest Time | Condition |
|---|---|---|---|---|---|---|
| 1 | Hibernate | 0 | — | 0:00:10 | — | — |
| 2 | Charge (CC) | 200 | 4200 | 0:10:00 | — | — |
| 3 | Rest | — | — | — | 1:00:00 | — |
| 4 | Loop | — | — | — | — | Repeat if V < 4200 mV |
Figure 1. Charge process voltage and current curve (Langtian test data)
During this stage, the voltage gradually increases with each pulse, and during the rest period, the voltage slowly stabilizes, reflecting the relaxation behavior of the battery system.
3.4 Discharging Process Configuration
| Step | Mode | Current (mA) | Lower Voltage (mV) | Time | Rest Time | Condition |
|---|---|---|---|---|---|---|
| 1 | Hibernate | 0 | — | 0:00:10 | — | — |
| 2 | Discharge (CC) | 200 | 2000 | 0:10:00 | — | — |
| 3 | Rest | — | — | — | 1:00:00 | — |
| 4 | Loop | — | — | — | — | Repeat if V > 2000 mV |
Figure 2. Discharge process voltage and current curve (Langtian test data)
During the discharge stage, the voltage curve decreases in a stepwise manner, and the voltage recovery during the rest period reflects the diffusion behavior of lithium ions within the electrode material.
4. Data Analysis
By analyzing the voltage response during current pulses and rest periods, the diffusion coefficient (D) can be derived from:
D = (4/π) * ( (m_B * V_M) / (M_B * S) )^2 * (ΔEs / ΔEτ)^2
where:
- m_B: Mass of active material
- V_M: Molar volume
- M_B: Molecular weight
- S: Electrode surface area
- τ: Pulse duration
By analyzing the changes of ΔE and ΔEs, the lithium-ion diffusion coefficient can be calculated, which quantifies the electrochemical kinetics of the material.
5. Tips for Reliable GITT Results
- Extend the rest period: recommended ≥1 h, ideally 10 h, to ensure voltage equilibrium.
- Reduce pulse current density: usually 0.05 C – 0.1 C to minimize polarization.
- Maintain a constant temperature environment to avoid the influence of temperature fluctuations.
- Enable logic control: use if/else in Langtian software to implement automatic loops.
- Average over multiple cycles to improve data reliability and reproducibility.
6. Summary
Using Langtian Battery Test Equipment, researchers can easily perform precise GITT experiments to evaluate diffusion behavior and kinetics of lithium-ion batteries.
