Capacitance-Power-Hysteresis Trilemma in Nanoporous Supercapacitors


Type
Article
Change log
Authors
Lee, Alpha A 
Vella, Dominic 
Goriely, Alain 
Kondrat, Svyatoslav 
Abstract

Nanoporous supercapacitors are an important player in the field of energy storage that fill the gap between dielectric capacitors and batteries. The key challenge in the development of supercapacitors is the perceived trade-off between capacitance and power delivery. Current efforts to boost the capacitance of nanoporous supercapacitors focus on reducing the pore size so that they can only accommodate a single layer of ions. However, this tight packing compromises the charging dynamics and hence power density. We show via an analytical theory and Monte Carlo simulations that charging is sensitively dependent on the affinity of ions to the pores, and that high capacitances can be obtained for ionophobic pores of widths significantly larger than the ion diameter. Our theory also predicts that charging can be hysteretic with a significant energy loss per cycle for intermediate ionophilicities. We use these observations to explore the parameter regimes in which a capacitance-power-hysteresis trilemma may be avoided.

Description
Keywords
51 Physical Sciences, 7 Affordable and Clean Energy
Journal Title
PHYSICAL REVIEW X
Conference Name
Journal ISSN
2160-3308
2160-3308
Volume Title
6
Publisher
American Physical Society (APS)