Electrode Design from Atomistic to Mesoscale Dimensions

The invention of rechargeable batteries has dramatically changed our landscapes and lives, underpinning the explosive worldwide growth of consumer electronics. Unfortunately, current battery technologies suffer from a myriad of challenges. Mechanistic understanding of compositional and electronic structure heterogeneities is imperative to facilitate the design of high-performing electrodes. X-ray microscopy observations indicate the formation of lithiation gradients in a Li_xV₂O₅ nanowire that arise from electron localization coupled to local structural distortions, giving rise to small polarons. I will also discuss the first direct visualization of patterns of compositional inhomogeneities within cathode materials. Two patterns are evidenced: core—shell separation and striping modulations. 3D compositional maps have been developed and translated to stress and strain maps, providing a hitherto unprecedented visualization of stress and strain inhomogeneities. Moreover, a cluster of interlaced Li_xV₂O₅ nanoparticles is evaluated, where increased heterogeneity at the interfaces suggest the exchange of Li-ions, implying a “winner-takes-all” behavior. Finally, I will discuss prospects for “beyond-Li” batteries.