Accurate and reliable testing is crucial for the advancement of battery technologies in various industries, ranging from energy storage to electric vehicles. Flexible and intuitive test equipment, including hardware and software, are critical to achieving precise results and maximizing the efficiency of the testing process. Ideal test equipment should be able to simplify the testing process, enable the control of large numbers of testing channels for high throughput battery testing, collect the data for Design-of-Experiments (DoE) protocols, and include powerful data analysis tools to parse the data and enable trend discovery.
1. Simplifying the Battery Testing Process:
Employing testing solutions that incorporate all the necessary tools and allow for automation, simplifies the testing process, and facilitates a comprehensive understanding of a battery’s behavior. Testing solutions with integrated hardware and software are essential to build such comprehensive testing protocols. The synchronous operation of flexible hardware and software solutions is required to streamline the experimental design process.
By combining hardware, such as Ivium’s OctoStat or IviCycle battery cyclers, with software platforms like Cycliscan and Ivilab, researchers benefit from a cohesive testing environment that eliminates complexities and enhances productivity. Ivium battery cyclers offer the added benefit of Electrochemical Impedance spectroscopy (EIS) capabilities built-in on every channel, further integrating testing hardware and software into one comprehensive system. This integration enables smooth communication and synchronization between hardware and software components, allowing researchers to focus on designing experiments that yield meaningful results rather than being burdened by technical intricacies and potential incompatibilities.
Ivium’s Cycliscan software (Figure 1) is a powerful tool for battery testing, offering a stepwise approach to protocol development. This software seamlessly incorporates DC and AC tests with loop and step conditions, providing researchers with a comprehensive testing environment. Its user-friendly interface allows researchers to easily configure test parameters and execute tests efficiently. By simplifying the testing protocol creation process, the Cycliscan software empowers researchers to conduct battery tests with precision and reliability.
Consequently, the combined integrated systems such as the Ivium hardware and software expedite the research and development cycle, accelerating advancements in battery technologies.
2. High Throughput Battery Testing
Thorough evaluation of battery performance requires testing over many charge and discharge cycles. Each cycle can last multiple hours, and hence, the duration of a test over 1000 cycles can take hundreds of days. In addition, different charge and discharge rates need to be probed. Also, for statistical reasons, it is advantageous to be able to test many identical batteries. Therefore, efficient battery testing requires the ability to control multiple testing channels simultaneously, which allows for shortening of the total testing time and increasing the throughput of testing cycles. Figure 2 shows the results of multiple charge-discharge cycles of a coin cell battery at a 0.5C rate. Overlaying the cycles shows low variation in the battery capacity, indicating stable behavior over this period.
The battery cyclers from Ivium Technologies enable researchers to control large numbers of channels in parallel to boost efficiency and maintain data quality. With a single instance of Ivium software, researchers can seamlessly manage up to 128 testing channels, significantly increasing throughput, and saving valuable time. This centralized control allows for easy coordination and synchronization of testing processes, ensuring consistent and reliable results across multiple battery samples or batches.
3. Design of Experiments (DoE) Protocols for Short Tests and Battery State of Health Grading
Design of experiments (DoE) is a method of planning and conducting experiments to optimize the performance of a system or process. DoE can be applied to battery testing to identify the factors that affect battery aging, capacity, power, and efficiency. The framework of DoE protocols provides an essential structure for efficient battery testing and accurate assessment of the battery’s state of health. Implementing DoE allows researchers to develop experimental designs that result in shorter test durations while maintaining data quality. By strategically varying factors such as temperature, current, voltage, and discharge rates, researchers can extract valuable insights into battery performance and degradation mechanisms. Furthermore, DoE protocols enable the grading of battery state of health based on specific criteria, facilitating the identification of battery lifespan, degradation patterns, and performance optimization.
Ivium hardware and software help with the data collection for input into a DOE algorithm by automating the series of experiments that are required to cover the design space for the procedure. The analysis software allows for the extraction of useful parameters, especially from impedance data.
4. Identifying Trends through Data Analysis
Battery testing generates vast amounts of data, which requires sophisticated analysis tools to extract meaningful insights. The Ivilab analysis software offers a wide variety of features to analyze data and discover trends. Researchers can utilize this software to analyze and visualize battery testing results, enabling them to identify patterns, correlations, and anomalies.
Figure 3 shows a Nyquist plot of a coin cell battery at an intermediate charge state. Points on the left most part of the plot are at high frequency, moving to lower frequency on the right. A depressed semi-circle is seen with the start of a diffusion tail. The semi-circle represents the charge transfer behavior of the active electrodes, and the tail is due to diffusion of lithium ions.
Ivilab analysis software’s batch fitting capabilities for Electrochemical Impedance Spectroscopy (EIS) data allow researchers to characterize battery performance and health more comprehensively, facilitating informed decision-making in battery development. A series of experiments recording the impedance spectra of the battery at various states of charge (SOC) can be fitted to an equivalent circuit model and the resulting parameters that are extracted can be used to track the SOC. The model is fitted to all the spectra in one process and the different parameters are plotted as a function of SOC. This allows for trends to be identified, leading to an increased understanding of the internal battery electrochemistry.
With the proliferation of battery-operated devices, accurate and reliable battery testing results are essential to aid in understanding battery performance. This can be achieved with multiple-channel, parallel battery test systems that incorporate high-quality hardware with intuitive and flexible software. Ivium Technologies has a range of products that meet these requirements including OctoStat and IviCycle where up to 128 channels can be controlled simultaneously and independently.
To learn more about Ivium Technologies’ powerful and flexible solutions for battery testing, watch our previous webinar: Empowering Battery Testing with Ivium Technologies – Nanoscience Instruments