Enhancing the Perfomance of Supercapacitors By Engineering Electrodes and Electrolytes

Securing availability of both energy and potable water is becoming the challenge chemical engineering has to overcome to secure humans propsperity. Electric double layer capacitors could serve both for storing electricity and for desalinating water (capacitive desalination has been pioneered in the mid 1950’s). Current research is focused on understanding how to improve the amount of electrolytes stored within the electrodes for a given applied voltage. We report here our recent molecular dynamics results along this research direction. We considered aqueous electrolytes and graphene electrodes (both pristine and patterned ones). Our results suggest that patterning the electrodes can in some cases enhance the capacitance. We explain these results using atomic-level structural obseravtions regarding the orientation of water, and the packing of NaCl ions near the charged electrodes. Quantities that could be verified experimentally will also be presented. The results presented could be useful for advancing our understanding of electric double layer capacitors, but also for undersing the transport of water and electrolytes in sub-surface formations.