Energy Storage

The storage of electrical energy and thermal energy are important to increasing the effectiveness of utilizing both conventional and renewable energy systems.  Given inherent fluctuations of energy demand that vary seasonally and diurnally, having scalable energy storage can greatly reduce the need for additional electric power, heating, or cooling capacity to meet peaking demand in a large number of applications.  Depending on the application, there is a wide range of storage needs from a few kW-hr (e.g. for homes and electric vehicles to a hundred MW-hr (e.g. for grid scale electricity and  district heating or cooling).

The Cornell work is focused in two areas – electrical storage in novel nano- structured engineered materials and thermal energy storage utilizing supercritical fluid mixtures of simple fluids and engineered nano-particles in integrated, distributed, MW-hr scale co-generation systems.  

Working in the Energy Materials Center (EMC2) with the Tito Abruna and Frank DiSalvo and in the KAUST center at Cornell, the Archer and Hanrath groups are using nanoparticle-based ionic materials (NIMS and NOHMS) along with other nano-structured composites to increase performance and lower costs for  batteries and capacitors. For example, their use of hydroxide conducting fuel cells provides a significant performance advantage with enhanced kinetics, relative to proton exchange membrane (PEM) fuel cells by permitting the use of cheaper, non-noble metal catalysts as opposed to platinum.  In addition, metal-air and lithium ion batteries are being evaluated because of their high specific energy densities and ability to operate at a scale needed for electric vehicles. There is currently significant interest in the development of hydroxide conducting PEMs, also known as alkaline anion exchange membranes (AAEMs), for fuel cells operating under basic conditions.

Thermal energy storage research being conducted collaboratively by the Tester, Hanrath, Stroock and Gianellis and Archer research group takes advantage of the tunability of properties supercritical fluids to achieve large enhancements in the heat capacity.  Heat capacities vary as strong functions of temperature and pressure in the vicinity of critical regions for particular mixture compositions. This tunable feature enables their use over a range of storage and supply temperatures from near ambient to more than 250oC making them adaptable for distributed heat supply for building and many industries as well as for electric power production utilizing efficient organic Rankine power cycles.     

Faculty Involved: Tito AbrunaLynden Archer, Frank DiSalvo, Emmanuel Gianellis, Tobias Hanrath, Lena Kourkoutis, Abe StoockJeff Tester.