Self-discharge and leakage current mitigation of neutral aqueous-based supercapacitor by means of liquid crystal additive
Journal article, 2020

Self-discharge is being recognized as one of the main obstacles to implementing the supercapacitor (SC) in standalone self-powered systems. Strategies for addressing this issue include the modification of electrodes, electrolytes, separators, and diverse device configurations. However, an improved self-discharge behavior is often achieved with a large compromise on other prominent figures of merit such as capacitance, energy density, or cycle life of the device. In this work, a thorough comparative electrochemical investigation of SCs containing a neutral aqueous electrolyte, 1 M Li2SO4, and with a liquid crystal (LC) additive, 2% 4-n-pentyl-4′-cyanobiphenyl (5CB) in 1 M Li2SO4, has been carried out at different states of charge. The results demonstrate that the device containing the LC additive 5CB exhibits a reduced self-discharge and leakage current without compromising the capacitive performance at different nominal voltages compared to the behavior of the device without 5CB. We suggest an explanation of the difference of the self-discharge behavior between the devices through tunability of the effective conductivity of the electrolyte composite upon applied voltages. As a result, in an open circuit condition, the device containing LC shows a slower diffusion of ions that facilitates a decreased self-discharge and leakage current.

Supercapacitor

Leakage current

Self-discharge

Liquid crystal

Electrorheology

Author

Mohammad Mazharul Haque

Chalmers, Microtechnology and Nanoscience (MC2), Electronics Material and Systems Laboratory

Qi Li

Chalmers, Microtechnology and Nanoscience (MC2), Electronics Material and Systems Laboratory

Anderson David Smith

Chalmers, Microtechnology and Nanoscience (MC2), Electronics Material and Systems Laboratory

Volodymyr Kuzmenko

Chalmers, Microtechnology and Nanoscience (MC2), Electronics Material and Systems Laboratory

Per Rudquist

Chalmers, Microtechnology and Nanoscience (MC2), Electronics Material and Systems Laboratory

Per Lundgren

Chalmers, Microtechnology and Nanoscience (MC2), Electronics Material and Systems Laboratory

Peter Enoksson

Chalmers, Microtechnology and Nanoscience (MC2), Electronics Material and Systems Laboratory

Journal of Power Sources

0378-7753 (ISSN)

Vol. 453 227897

Subject Categories

Materials Chemistry

Other Electrical Engineering, Electronic Engineering, Information Engineering

Condensed Matter Physics

DOI

10.1016/j.jpowsour.2020.227897

More information

Latest update

4/1/2020 1