Electrochemical discharge of nanocrystalline magnetite: structure analysis using X-ray diffraction and X-ray absorption spectroscopy.
Magnetite (Fe3O4) is an abundant, low cost, environmentally benign material with potential application in batteries. Recently, low temperature coprecipitation methods have enabled preparation of a series of nanocrystalline magnetite samples with a range of crystallite sizes. Electrochemical cells based on Li/Fe3O4 show a linear increase in capacity with decreasing crystallite size at voltages ≥1.2 V where a 2× capacity improvement relative to commercial (26.2 nm) magnetite is observed. In this report, a combination of X-ray powder diffraction (XRD) and X-ray absorption spectroscopy (XAS) is used to measure magnetite structural changes occurring upon electrochemical reduction, with parent Fe3O4 crystallite size as a variable. Notably, XAS provides evidence of metallic iron formation at high levels of electrochemical reduction.
Department of Chemistry, Stony Brook University, Stony Brook, NY 11790, USA. kenneth.takeuchi.1@stonybrook.edu amy.marschilok@stonybrook.edu esther.takeuchi@stonybrook.edu.
Melissa C
MC
Menard
Kenneth J
KJ
Takeuchi
Amy C
AC
Marschilok
Esther S
ES
Takeuchi
D004563:Electrochemistry; D008094:Lithium / Q000737:chemistry; D058185:Magnetite Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D056928:X-Ray Absorption Spectroscopy; D014961:X-Ray Diffraction
D058185:Magnetite Nanoparticles; D008094:Lithium