Voltage Dependent Charge Storage Modes and Capacity in Subnanometer Pores
- Clemson University
- Rensselaer Polytechnic Institute (RPI)
- ORNL
Using molecular dynamics simulations, we show that charge storage in subnanometer pores follows a distinct voltage-dependent behavior. Specifically, at lower voltages, charge storage is achieved by swapping co-ions in the pore with counterions in the bulk electrolyte. As voltage increases, further charge storage is due mainly to the removal of co-ions from the pore, leading to a capacitance increase. The capacitance eventually reaches a maximum when all co-ions are expelled from the pore. At even higher electrode voltages, additional charge storage is realized by counterion insertion into the pore, accompanied by a reduction of capacitance. The molecular mechanisms of these observations are elucidated and provide useful insight for optimizing energy storage based on supercapacitors.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). National Center for Computational Sciences (NCCS)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 1043333
- Journal Information:
- Journal of Physical Chemistry Letters, Vol. 3, Issue 13
- Country of Publication:
- United States
- Language:
- English
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