Application of a Multiscale, Molecular- to Meso-Scale Perspective towards the Investigation of Fe 3 O 4 as an Energy Storage Material

With a theoretical capacity exceeding 900 mAh/g, magnetite (Fe3O4) is an interesting anode material for lithium ion batteries. This report highlights observations relating to charge transfer capabilities of Fe3O4 over several length scales. Ex-situ extended x-ray absorption fine structure (EXAFS) and transmission electron microscopy (TEM) data provide the foundation for study of the atomic-scale mechanism. The function of the Fe3O4 electrode material is studied both in nanometer sized particles (as observed by TEM), and in micron sized aggregates (as observed by transmission x-ray microscopy (TXM)). Notably, the recent development of electrically conducting binders towards modification of mesoscale electrode composition and structure demonstrates significant gains in capacity and capacity retention, despite utilizing the same Fe3O4 particles.