The rapid growth of the electric vehicle market and the increasing demand for portable electronics have driven the need for advanced energy storage systems. In recent years, lithium-ion batteries have emerged as a promising solution due to their high energy density, long cycle life, and low self-discharge rate. However, to further improve their performance and safety, a deeper understanding of the complex processes occurring within the batteries is essential. One such approach is the use of advanced analytical techniques, such as Focussed Ion Beam Secondary Ion Mass Spectrometry (FIB-SIMS) and Focussed Ion Beam Scanning Electron Microscopy (FIB-SEM). In this blog, we will explore how the integration of these powerful techniques can enable highly sensitive detection of lithium and provide valuable insights into lithium-ion battery research.
FIB-SIMS: A Game Changer for Lithium Detection
The detection and analysis of lithium in lithium-ion batteries have always been a challenge due to its low mass and the presence of numerous other elements with similar masses. Traditional analytical techniques, such as X-ray based methods, struggle to provide accurate and reliable information on lithium distribution and concentration. This is where FIB-SIMS comes into play, offering superior sensitivity and spatial resolution for lithium detection.
FIB-SIMS is a powerful technique that combines the capabilities of a Focused Ion Beam (FIB) with Secondary Ion Mass Spectrometry (SIMS) to provide high-resolution elemental and isotopic information. The FIB is used to sputter the sample surface, generating secondary ions that are subsequently analyzed by SIMS. This combination allows for the detection of the entire periodic table of elements, with enhancements in low mass elements and isotopes such as lithium, with high sensitivity and precision.
Integration with FIB-SEM: A Perfect Match for High-Resolution Analysis
To further enhance the capabilities of FIB-SIMS, researchers have begun integrating it with focussed ion beam scanning electron microscopes (FIB-SEM). This combination offers a myriad of benefits for lithium-ion battery research, including:
1. Correlative imaging: FIB-SEM enables the acquisition of high-resolution electron images of the sample, providing crucial information on its morphology and microstructure. By correlating these images with the elemental maps obtained from FIB-SIMS, researchers can gain a comprehensive understanding of the spatial distribution of lithium and its relationship with the battery’s microstructure.
2. In-situ sample preparation: FIB-SEM allows for precise and controlled milling of the sample, enabling the preparation of cross-sections or thin lamellae for further analysis. This in-situ sample preparation capability ensures minimal sample damage and contamination, resulting in more accurate and reliable data.
3. 3D elemental analysis: By combining FIB-SEM and FIB-SIMS, researchers can perform 3D elemental analysis of lithium-ion batteries. This is achieved by sequentially milling and analyzing the sample, generating a series of 2D elemental maps that can be reconstructed into a 3D volume. This 3D information provides valuable insights into the distribution and migration of lithium within the battery, which can help in understanding the degradation mechanisms and improving the battery’s performance.
The integration of FIB-SIMS and FIB-SEM has proven to be a powerful combination for lithium-ion battery research, offering unparalleled sensitivity and resolution for low mass detection of lithium. By providing detailed information on lithium distribution, concentration, and migration, these advanced analytical techniques can significantly contribute to the development of more efficient and safer energy storage systems. As the demand for lithium-ion batteries continues to grow, the role of FIB-SIMS and FIB-SEM in understanding and optimizing these vital energy storage devices.