High Energy Density Asymmetric Capacitors

Principal Investigator: Levi T. Thompson, University of Michigan, ltt_at_umich.edu
Faculty: Paul Rasmussen, University of Michigan
Student: Priyanka Pande, Abdoulaye Djire, University of Michigan
Government: Yi Ding, Ground Vehicle Power & Mobility, U.S. Army TARDEC
Industry: Saemin Choi, Inmatech

Batteries are the principal devices used for military and commercial energy storage applications. While these devices can have energy densities exceeding 100 Wh/kg, this energy is difficult to fully access in high power and pulsed applications due to the relatively slow kinetics associated with their redox processes. Supercapacitors are based on very fast and highly reversible processes and offer a unique combination of high power densities and modest energy densities. These devices can also be included in hybrid configurations to manage short, high power pulses, thereby, minimizing stresses on the primary energy storage device (e.g. battery or fuel cell). Currently available supercapacitors are based on high surface area, engineered carbons and non-aqueous electrolytes, and can deliver up to ~5 Wh/kg. To achieve broader application, next generation supercapacitors will have to deliver much higher energy densities.

The overall goal of the proposed project is to demonstrate asymmetric supercapacitor concepts that will enable devices capable of delivering more than 10 Wh/kg at 5,000 W/kg. These devices will combine high capacity pseudocapacitive materials in asymmetric cell configurations in low-cost aqueous electrolytes.

The following objectives were devised to achieve the project goal, of which the first two have been completed.

  1. Explore methods to maximize properties of nitride or carbide based active materials;
  2. Develop methods for fabrication of cathodes containing high surface area nitrides or carbides, and anodes containing Mn or Ni oxides;
  3. Design and assemble asymmetric prototype cells using appropriate electrolytes;
  4. Evaluate the performance of prototype for technologically relevant load profiles.

Publications:

  • Priyanka Pande, Paul G. Rasmussen, Levi T. Thompson, "Charge storage on nanostructured early transition metal nitrides and carbides," Journal of Power Sources, Volume 207, 1 June 2012, Pages 212-215, ISSN 0378-7753
    doi:10.1016/j.jpowsour.2012.01.028
  • Priyanka Pande, Aniruddha Deb, James Penner-Hahn, Alice Sleightholme, Paul Rasmussen and Levi T. Thompson, “Charge Storage Mechanisms for Early Transition Metal Nitrides and Carbides,” ACS Fall 2012 National Meeting, Philadelphia, August 2012.
  • Priyanka Pande, Paul Rasmussen, Levi T Thompson, “Investigation of Charge Storage Mechanisms for Nanostructured Metal Nitride Supercapacitor Electrodes,” Power Sources Meeting, Las Vegas, NV, June 2012.
  • P. Pande, A. Sleightholme, P. Rasmussen, and L. Thompson, “Mechanistic and Design Aspects of Transition Metal Nitride Based Supercapacitors," Electrochemical Society Meeting, Seattle, WA, May 2012.
  • Priyanka Pande, Paul Rasmussen and Levi T Thompson, “Nanostructured Metal Nitrides and Carbides as Electrode Materials for Electrochemical Capacitors,” 218th Electrochemical Society Meeting, Las Vegas, October 2010.
  • Priyanka Pande, Paul Rasmussen and Levi T Thompson, “Transition Metal Nitrides and Carbides as Electrode Materials for Electrochemical Capacitors,” 41st Central Regional Meeting of the American Chemical Society, Dayton (Ohio), June 2010.
  • Levi T. Thompson, Saemin Choi, and Paul G. Rasmussen, “High Performance Transition Metal Carbides and Nitrides Based Asymmetric Supercapacitors,” USPTO Serial No. 61/392,311.