Grant: Research Tools and Instruments

An impedance/gain-phase frequency response analyzer is requested to enable us to carry out a.c.-impedance studies of materials that possess mixed electronic/ionic conductivity. Such measurements are critical to separate the contributions from the two components of the conductivity, and in particular to measure the ion conductivity of superionic conductors. These studies apply to the bulk of the materials which we make that target these properties namely, mixed Li-ion/electronic conduction for energy storage cells. The infrastructure is also vital for the determination of grain boundary impedance vs bulk impedance in our electrode materials for energy storage and conversion cells. Up to now, we have made do with impedance data from our Biologic VMP-3 suite of instruments (dedicated galvanostat/potentiostats which have a four narrow-frequency impedance channels embedded in them) to provide general information on impedance in our batteries, but as we move forward - with new materials, new systems, and many more samples with a wide range of ion conductivity properties - the additional frequency range, capability, resolution and accuracy of a stand-alone impedance analyzer is required to measure the ion conduction properties of specific materials (rather than simply impedance of entire battery assemblies). The equipment is especially necessary for the Nazar group's new project on solid state ""superionic"" conductors and solid state batteries (funding from NSERC and BASF). Without a powerful, full-fledged impedance analyzer, solid state ion conduction properties simply cannot be determined, and thus the materials effort would be wasted. The Pope and Tang labs will use the impedance analyzer to enable accurate measurements of conductivity in graphene-based supercapacitive and pseudo-capacitive materials which possess mixed ionic and electronic conductivity. There are NO functioning impedance analyzers at U Waterloo. This is equipment that would be used on a daily basis, 7 hours a day, and therefore access to equipment external to campus would not be viable. Funds for a Solartron 1260A analyzer are requested, which is the gold-standard impedance analyzer used around the world for such studies.