E.V. Timofeeva, J.P. Katsoudas, C.U. Segre, D. Singh
Argonne National Laboratory, US
nanofluid, flow battery, XAS, EXAFS, in-situ experiment
Nanomaterial suspensions in liquids (nanofluids) are the new expanding area in nanotechnology, with applications as wide as biomedical, lubrication, thermal management, energy generation, energy conversion, and energy storage. Variety and unique characteristics of nanomaterials allow for engineering the multifunctional fluid media with new desired characteristics. We will present experimental results demonstrating applicability of rechargeable nanofluid electrodes for high energy density flow batteries. The rechargeable nanofluid technology is a transformational advancement of redox flow battery concepts, where energy is stored and released through a reversible electrochemical reaction in two electrolytes. The cathodic and anodic electrolytes are stored externally to the battery and circulated through the cell(s) of the reactor as required, providing almost limitless number of charging and discharging cycles since red/ox transfer occurs at atomic/molecular level. The main limitation of electrolyte-based flow batteries is low energy densities (40 Wh/l) due to the limited solubility of salts. This limitation can be overcome with stable dispersions of solid electroactive nanoparticles in the liquid. Increased volume concentrations of electroactive nanoparticles will dramatically increase the energy density (up to 30 times) and would also allow using electroactive compounds with low solubility.