Dualbeam Platform Applications in Lithium Battery Research

Abstract

Lithium batteries are energy storage systems with highly complex microstructures. To understand the performance of the battery it is essential to accurately characterize the battery microstructure at multiple length scales. However, there are multiple challenges in battery characterization such as beam damage, imaging liquid phases and getting to representative volumes.The DualBeam, also known as focused ion beam–scanning electron microscope (FIB-SEM) technique is an analytical method combining an ion beam for materials processing and an electron column for imaging to enable 2D and 3D characterization at the nanometer scale. In this presentation the application of three different DualBeam techniques for battery characterization and how to handle the imaging challenges are discussed for different sample types.A battery separator is a beam sensitive sample and imaging conditions need to be optimized to avoid damaging the separator morphology. By using cryo techniques in a Ga-based FIBSEM, the cross-section and 3D structure of a separator sample is analyzed. The second example deals with a thick NMC electrode sample. Considering the thickness of the cathode (>70 µm) and the active particle size (~10 µm) particle size, a field of view >100 um is needed to get to a representative volume. The combination of Xe-plasma FIB (PFIB) with Avizo software is used to study the electrode microstructure evolution during cycling to better understand the degradation mechanism. The final example is about accessing the liquid-solid interphase inside of the electron microscope. By using a laser PFIB under cryogenic condition, the interphase of the liquid-solid in a Li-metal battery is explored, which is critical to decipher the root cause for cycling inefficiency.DualBeam technology enables new analytical capabilities for materials research while opening up exciting opportunities for advancing battery development. It is expected to remain an indispensable technique for supporting battery innovation in both academic and industrial environments.