Interaction analysis between binder and particles in multiphase slurriesElectronic supplementary information (ESI) available. See DOI: 10.1039/c3an36720g

A multiphase slurry for rechargeable lithium-ion batteries is prepared using an active material, a carbon conductive, a polymeric binder and a solvent, and its physicochemical characteristics is evaluated in this study. The polymer binder interacting with particles in the slurry plays a crucial role in constructing the internal configuration of slurry components. The internal structure and dispersion states of the slurry components, which affect battery fabrication processes such as coating and even determine the final performance of battery cells, are changed over time. Experimental measurements such as spectroscopic, rheological, morphological, and electrical tests are carried out. Morphological specimens are freeze-dried to fix the locations of the slurry components. The existence of a network structure (or flocculation) is verified by viscoelastic property measurements and morphological observations. Electrical properties of the slurry vary mainly depending on the dispersion state of the carbon conductive. In addition, the dispersity index is introduced as a new quantity representing the dispersion state of the slurry components. The dispersity index is used to evaluate the internal structure of battery slurries in a systematic, quantitative manner and the structure-property relationship is analyzed.