“Synergizing High Capacitance with Fast Charging: Materials Design and Mechanisms”
As electronic technology advances, the need in safe and long-lasting energy storage devices that occupy minimum volume arises. Short charging times of several seconds to minutes, with energy densities comparable to those of batteries, can be achieved in pseudocapacitors. These are sub-class of supercapacitors, where capacitance is mediated by fast redox reactions and can enable at least an order of magnitude more energy to be stored than in typical electrical double layer capacitors. Transition metal oxides (e.g. RuO2, MnO2) and conducting polymers (e.g. polyaniline) serve as typical examples. However, these materials are often high in cost and/or suffer from low cycling stability. As a result, the search for new pseudocapacitive materials constitutes an important direction today. In my talk, I will discuss how the key performance metrics of pseudocapacitors – capacitance and charging rates – can be pushed to the limits in the materials that combine good electrical and ionic conductivities (ensuring fast charge transfer and hence charging rates) with high density of redox-active and ionically accessible sites (enabling high capacitance and charging rates). In particular, I will present the electrochemistry of new layered materials such as 2D transition metal carbides (MXenes) and hexaaminobenzene-based conductive MOFs for energy storage applications, with an emphasis on the mechanism of charge storage and factors affecting the electrochemical performance.
Date(s) - Feb 15, 2019
10:00 am - 11:00 am
Boelter Hall 3400
420 Westwood Plaza, Los Angeles CA 90095