Battery testing is a crucial process in the development, manufacturing, and maintenance of various types of batteries. They play a vital role in powering a wide range of devices, from small electronic gadgets to electric vehicles and renewable energy storage systems. Batteries’ performance, reliability, and safety are paramount, and thorough testing is essential to ensure these aspects are met.
Battery testing involves a series of procedures and evaluations designed to assess a battery’s overall health and capabilities. This testing encompasses various parameters, including capacity, energy density, efficiency, cycle life, self-discharge rate, thermal stability, and safety measures. The information gathered from these tests helps manufacturers and researchers optimize battery designs, materials, and manufacturing processes.
Battery cyclers play an important role in the battery testing process helping to determine capacity, energy density, cycle life, and self-discharge rate among other things. Choosing the right battery cycler for your desired battery testing protocol requires several considerations, including:
1. The Types of Batteries Being Tested
Different types of batteries require different specifications for the battery cycling channels to achieve the desired testing regimen. Small capacity batteries used for material and engineering design evaluation only require low current capabilities and many testing channels can be fit into a convenient package. Additionally, the batteries can be directly attached to the tester using simple battery holders mounted on printed circuit boards. More power may be required to adequately test the battery for larger-capacity batteries, necessitating larger test systems. For a system with the same footprint as one that is used for testing smaller batteries, fewer channels can be accommodated due to the increased dimensions of the power unit. For very large batteries, a booster system may need to be attached to increase the maximum current that is available. The addition of a booster also enhances the flexibility of a measurement system, since it will be able to support the testing of both small devices and large devices with the same base hardware.
2. Available Testing Modes
Many commercially available battery cyclers are limited in the types of experiments that can be performed, so it is critical to assess which testing modes are supported when choosing battery testing hardware. While battery measurements are typically made galvanostatically, in current-controlled mode, other measurement modes can yield useful information. Having the option to control the potential as well as run traditional electrochemical experiments like cyclic voltammetry and corrosion tests unlocks a wealth of information regarding battery health, life cycle, and more. The additional potentiostat functionality enables you to construct a more complete picture of the performance envelope of the battery. Corrosion of the current collectors is one application in which using a battery cycler as a potentiostat demonstrates the advantageous nature of dual-use battery cyclers/potentiostats.
3. Number of Channels
Increased battery cycle life is a major focus of battery developers and testing the longevity of new battery designs is the principal way to determine the cycle life. However, it typically takes approximately 5 hours to fully discharge a battery in a controlled manner. Hence, battery cycling tests can take a significant amount of time. For a full test with up to 1000 cycles, it would take 208 days to complete the protocol on a single battery. While there are proposed methods of speeding up this process, it is not possible to get the same information without completing a full discharge test. Therefore, increasing the number of channels for battery testing is advantageous, as it enables the completion of cycling tests on multiple batteries simultaneously. In cases where you need to obtain statistically significant information about the specifications and performance of a battery, a higher channel count is especially beneficial.
4. Software Features
High-quality measurements and increased productivity require that the ideal hardware needs to be paired with software powerful enough to utilize its full potential. The control software should include simple battery cycling protocols as well as handling more complicated tasks needed to streamline the process of designing and executing experiments. The battery cycler software should include the techniques to enable the use of the same battery testing equipment for more basic battery materials tests. An extremely versatile system can be had if the software is paired with suitable hardware that allows measurement over a wider current range than a traditional battery cycler.
5. Built-in Impedance Measurements
Having hardware to make impedance measurements built-in on each testing channel is extremely beneficial for increasing the functionality of battery cycling equipment. Electrochemical Impedance Spectroscopy (EIS) provides an additional layer of information about battery device performance and is a commonly used technique for assessing the degradation mechanisms of batteries as they are cycled over time. Factory-integrated hardware allows for high-quality impedance measurements to be performed without having to reattach the battery to a different system or struggle with the additional cabling required for a third-party system add-on to a battery cycler. Minimizing cables for these experimental setups shortens the signal path length, reducing noise and other high-frequency effects. With built-in hardware, impedance measurements can seamlessly be included in the battery testing protocol and can be used as a regular part of the overall testing regimen.
Conclusion
Battery Cyclers play an important role in the evaluation of battery performance characteristics. Flexibility and ease of use enable battery cyclers to perform a wide variety of tests on batteries of different sizes. There are many configurations of battery cyclers with varying specifications and channel numbers, and your specific needs should be carefully considered before deciding which instrument is right for you.
