Abonnement à la biblothèque: Guest

ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

ELECTRON AND ION TRANSPORT WITHIN THE HEAT GENERATION OF GRAPHENE-BASED SUPERCAPACITORS

Get access (open in a dialog) DOI: 10.1615/IHTC16.ecl.022731
pages 4123-4132

Résumé

Heat generation in supercapacitors will result in serious energy waste and a series of negative impacts to the devices and energy storage performance. Joule heat caused by internal resistance is a major source of the heat generation of supercapacitors, which is strongly related to the transport behavior of energy carriers (i.e., electrons and ions). In this work, electrochemical and thermal tests are conducted to study the heat generation performance of graphene-based supercapacitors. A density functional theory calculation combined with non-equilibrium Green's function is employed to explore the electron transport behavior. Ion diffusion in nanoscale graphene channels is investigated with molecular dynamics simulations. Results show that, compared with those employing activated carbons, graphene-based supercapacitor presents lower heat generation rate, consistent with its lower internal resistance. The resistance of electron transport is mainly from graphene inter-layers and the interface between graphene and current collector. Ion transport within nano-sized graphene channels presents different properties with those in bulk electrolytes. Sub-nanometer channels could induce deformation of hydration shells, leading to higher resistance. The results of this work may provide useful information to guide the design and optimization of graphene-based supercapacitors with reduced heat generation.