skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Impurity effects on ionic-liquid-based supercapacitors

Journal Article · · Molecular Physics
 [1];  [2];  [3];  [1]
  1. Univ. of California, Riverside, CA (United States)
  2. Univ. of California, Riverside, CA (United States); East China Univ. of Science and Technology, Shanghai (People's Republic of China)
  3. Brigham Young Univ., Provo, UT (United States)
+ Show Author Affiliations

Small amounts of an impurity may affect the key properties of an ionic liquid and such effects can be dramatically amplified when the electrolyte is under confinement. Here the classical density functional theory is employed to investigate the impurity effects on the microscopic structure and the performance of ionic-liquid-based electrical double-layer capacitors, also known as supercapacitors. Using a primitive model for ionic species, we study the effects of an impurity on the double layer structure and the integral capacitance of a room temperature ionic liquid in model electrode pores and find that an impurity strongly binding to the surface of a porous electrode can significantly alter the electric double layer structure and dampen the oscillatory dependence of the capacitance with the pore size of the electrode. Meanwhile, a strong affinity of the impurity with the ionic species affects the dependence of the integral capacitance on the pore size. Up to 30% increase in the integral capacitance can be achieved even at a very low impurity bulk concentration. By comparing with an ionic liquid mixture containing modified ionic species, we find that the cooperative effect of the bounded impurities is mainly responsible for the significant enhancement of the supercapacitor performance.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Energy Frontier Research Centers (EFRC) (United States). Fluid Interface Reactions, Structures and Transport Center (FIRST)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
AC05-00OR22725; ERKCC61
OSTI ID:
1399241
Alternate ID(s):
OSTI ID: 1388372
Journal Information:
Molecular Physics, Vol. 115, Issue 4; ISSN 0026-8976
Publisher:
Taylor & FrancisCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 13 works
Citation information provided by
Web of Science

References (57)

Ionic-liquid materials for the electrochemical challenges of the future journal July 2009
Structures and correlation functions of multicomponent and polydisperse hard-sphere mixtures from a density functional theory journal July 2004
Water in Ionic Liquids at Electrified Interfaces: The Anatomy of Electrosorption journal October 2014
Anomalous or regular capacitance? The influence of pore size dispersity on double-layer formation journal September 2016
Ion Partitioning between Charged Micropores and Bulk Electrolyte Solution. Mixtures of Mono- and Divalent Counterions and Monovalent Co-Ions journal August 1995
Applications of ionic liquids in the chemical industry journal January 2008
Experimental measurement of the hygroscopic grade on eight imidazolium based ionic liquids journal April 2009
Microscopic density functional theory of wetting and drying of a solid substrate by an explicit solvent model of ionic solutions journal December 2009
A Generic Model for Electric Double Layers in Porous Electrodes journal April 2016
Ionic Liquids at Electrified Interfaces journal March 2014
Charging Ultrananoporous Electrodes with Size-Asymmetric Ions Assisted by Apolar Solvent journal May 2016
Capacitance in carbon pores of 0.7 to 15 nm: a regular pattern journal January 2011
Influence of chloride, water, and organic solvents on the physical properties of ionic liquids journal January 2000
Interfacial ionic ‘liquids’: connecting static and dynamic structures journal December 2014
Size Selectivity of Narrow Pores journal July 2000
Ion distributions, exclusion coefficients, and separation factors of electrolytes in a charged cylindrical nanopore: A partially perturbative density functional theory study journal October 2009
Density Functional Theory for Planar Electric Double Layers:  Closing the Gap between Simple and Polyelectrolytes journal April 2006
Enhancing the Capacitive Performance of Electric Double-Layer Capacitors with Ionic Liquid Mixtures journal April 2016
Mobility and solvation of ions in channels journal November 1996
Relation between the Ion Size and Pore Size for an Electric Double-Layer Capacitor journal March 2008
The interface ionic liquid(s)/electrode(s): In situSTM and AFM measurements journal January 2012
Density functional theory for differential capacitance of planar electric double layers in ionic liquids journal March 2011
Chemical and electrochemical ageing of carbon materials used in supercapacitor electrodes journal November 2008
A superionic state in nano-porous double-layer capacitors: insights from Monte Carlo simulations journal January 2011
Nanowindow-Regulated Specific Capacitance of Supercapacitor Electrodes of Single-Wall Carbon Nanohorns journal January 2007
Monte Carlo and Poisson-Boltzmann study of electrolyte exclusion from charged cylindrical micropores journal January 1993
Anomalous Increase in Carbon Capacitance at Pore Sizes Less Than 1 Nanometer journal September 2006
The large scale synthesis of pure imidazolium and pyrrolidinium ionic liquids journal January 2007
Microscopic Insights into the Electrochemical Behavior of Nonaqueous Electrolytes in Electric Double-Layer Capacitors journal March 2013
Microstructure and Capacitance of the Electrical Double Layers at the Interface of Ionic Liquids and Planar Electrodes journal February 2009
A perturbative density functional theory for square-well fluids journal May 2011
A classical density functional theory for interfacial layering of ionic liquids journal January 2011
Oscillation of Capacitance inside Nanopores journal December 2011
Monte Carlo Simulation for the Double Layer Structure of an Ionic Liquid Using a Dimer Model: A Comparison with the Density Functional Theory journal August 2012
Charge neutrality breakdown in confined aqueous electrolytes: Theory and simulation journal September 2016
Towards a microscopic theory of wetting by ionic solutions. I. Surface properties of the semi-primitive model journal September 2006
Structures of hard-sphere fluids from a modified fundamental-measure theory journal December 2002
Wetting and drying scenarios of ionic solutions journal March 2011
Structure and dynamics of electrical double layers in organic electrolytes journal January 2010
Causes of supercapacitors ageing in organic electrolyte journal September 2007
Effect of dissolved LiCl on the ionic liquid–Au(111) electrical double layer structure journal January 2012
On the theoretical description of weakly charged surfaces journal March 2015
Purification or contamination? The effect of sorbents on ionic liquids journal January 2008
A review of electrolyte materials and compositions for electrochemical supercapacitors journal January 2015
Superionic state in double-layer capacitors with nanoporous electrodes journal December 2010
X-Ray reflectometry studies on the effect of water on the surface structure of [C4mpyr][NTf2] ionic liquid journal January 2009
Solvent Effect on the Pore-Size Dependence of an Organic Electrolyte Supercapacitor journal June 2012
Wetting of a solid substrate by a “civilized” model of ionic solutions journal May 2010
Supercapacitor Capacitance Exhibits Oscillatory Behavior as a Function of Nanopore Size journal October 2011
Non-Haloaluminate Room-Temperature Ionic Liquids in Electrochemistry—A Review journal August 2004
Interionic Interactions in Conducting Nanoconfinement journal December 2013
Double-Layer in Ionic Liquids:  Paradigm Change? journal May 2007
On the theory of electric double layer with explicit account of a polarizable co-solvent journal May 2016
Superionic state in double-layer capacitors with nanoporous electrodes text January 2010
Interfacial Ionic Liquids: Connecting Static and Dynamic Structures text January 2014
On the theory of electric double layer with explicit account of a polarizable co-solvent text January 2016
Charge neutrality breakdown in confined aqueous electrolytes: theory and simulation text January 2016

Cited By (3)

Computational Insights into Materials and Interfaces for Capacitive Energy Storage journal April 2017
Microscopic dynamics in room-temperature ionic liquids confined in materials for supercapacitor applications journal January 2020
Wettability of ultra-small pores of carbon electrodes by size-asymmetric ionic fluids journal February 2020

Linked Research (2)

Figures / Tables (9)

Figure 1.(p. 3)figure Figure 1.
Figure 2.(p. 7)figure Figure 2.
Figure 3.(p. 9)figure Figure 3.
Figure 4.(p. 10)figure Figure 4.
Figure 5.(p. 11)figure Figure 5.
Figure 6.(p. 12)figure Figure 6.
Figure 7.(p. 13)figure Figure 7.
Figure 8.(p. 15)figure Figure 8.
Figure 9.(p. 16)figure Figure 9.

Similar Records

Boosting the Performance of Ionic-Liquid-Based Supercapacitors with Polar Additives
Journal Article · Tue Oct 18 00:00:00 EDT 2016 · Journal of Physical Chemistry. C · OSTI ID:1399241
Boosting the Performance of Ionic-Liquid-Based Supercapacitors with Polar Additives
Journal Article · Wed Oct 05 00:00:00 EDT 2016 · Journal of Physical Chemistry. C · OSTI ID:1399241
Electric double layer capacitance for ionic liquids in nanoporous electrodes: Effects of pore size and ion composition
Journal Article · Fri Nov 03 00:00:00 EDT 2017 · Journal of Molecular Liquids · OSTI ID:1399241
+1 more

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
25 ENERGY STORAGE
electrical double layer
energy storage
classical density functional theory
catalysis (heterogeneous)
solar (fuels)
energy storage (including batteries and capacitors)
hydrogen and fuel cells
electrodes - solar
mechanical behavior
charge transport
materials and chemistry by design
synthesis (novel materials)