Effects of Inhomogeneities—Nanoscale to Mesoscale—on the Durability of Li-Ion Batteries

We review work from our laboratory that suggests to us that most Li-ion battery failure can be ascribed to the presence of nano- and microscale inhomogeneities that interact at the mesoscale, as is the case with almost every material, and that these inhomogeneities act by hindering Li transport. (Li does not get to the right place at the right time.) For this purpose, we define inhomogeneities as regions with sharply varying properties—which includes interfaces—whether present by “accident” or design. We have used digital image correlation, X-ray tomography, FIB-SEM serial sectioning, and isotope tracer techniques with TOF-SIMS to observe and quantify these inhomogeneities. We propose new research approaches to make more durable, high energy density lithium-ion batteries.