To view this presentation:

  • If you have an MRS account, click the Login button above.
  • New to MRS?  Create a free account here



  0       0

2014 MRS Spring Meeting


N10.06 - Mixtures of Ionic Liquids and Organic Solvents as Electrolytes for Electrochemical Capacitors


Apr 25, 2014 2:45pm ‐ Apr 25, 2014 3:00pm

Description

The performance of electrochemical capacitors (ECs) is determined by the properties of their main components electrodes and the electrolyte. The energy density of EC is directly related to specific capacitance of the electrodes and the working potential of the device. In recent years, Ionic liquids (ILs) have attracted a lot of attention as electrolytes for ECs as they are stable at higher potentials compared to conventional aqueous and organic electrolytes, leading to higher energy density of the device.

However, neat ionic liquids have much higher viscosities compared to electrolytes based on organic solvents such as acetonitrile (AN) or propylene carbonate (PC) and they are also more expensive. In this study, we introduce mixtures of ionic liquids and PC as effective substitutes for conventional organic electrolytes. We show that by using these mixtures as the electrolyte instead of a typical organic electrolyte (tetraethylammonium tetrafluoroborate (TEA BF4) in PC), we can extend the working potential and even cycle life of ECs without sacrificing the rate performance. The ionic liquids all contain the tetrafluoroborate anion just like the organic electrolyte used for comparison.

The three different cations are 1-Butyl-1-methylhomopiperidinium, 1-Ethyl-1-methylpyrrolidinium, and 1,1-Dimethylpyrrolidinium. In all cases, multilayered graphene sheets are used as the electrode material. Electrochemical performance is assessed through galvanostatic cycling, cyclic voltammetry, and impedance spectroscopy. Results indicate better capacitive performance of all three IL electrolytes compared to the conventional organic electrolyte as well as an impressive capacitive stability over 10000 cycles. These electrolytes find applications in ECs with high energy density and long lifetime requirements.

Speaker(s):

You must be logged in and own this session in order to post comments.

Print Certificate
Review Answers
Print Transcript
Completed on: token-completed_on
Review Answers
Please select the appropriate credit type:
/
test_id: 
credits: 
completed on: 
rendered in: 
* - Indicates answer is required.
token-content

token-speaker-name
token-index
token-content
token-index
token-content
token-index
token-content
token-index
token-content
token-index
token-content
token-index
token-content
/
/
token-index
token-content
token-index
token-content