Three-Dimensional Visualization of Conductive Domains in Battery Electrodes with Contrast-Enhancing Nanoparticles
journal contributionposted on 2018-09-05, 00:00 authored by Samantha L. Morelly, Jeff Gelb, Francesco Iacoviello, Paul R. Shearing, Stephen J. Harris, Nicolas J. Alvarez, Maureen H. Tang
Replacing conductive carbon black with commercial carbon-coated iron nanoparticles yields an effective contrast-enhancing agent to differentiate between active material, conductive additive, and binder in lithium-ion battery electrodes. Nano-XCT resolved the carbon–binder domain with 126 nm voxel resolution, showing partial coatings around the active material particles and interparticle bridges. In a complementary analysis, SEM/EDS determined individual distributions of conductive additives and binder. Surprisingly, the contrast-enhancing agents showed that the effect of preparation parameters on the heterogeneity of conductive additives was weaker than on the binder. Incorporation of such contrast-enhancing additives can improve understanding of processing–structure–function relationships in a multitude of devices for energy conversion and storage.