Nanostructured all-solid-state supercapacitor based on Li 2 S-P 2 S 5 glass-ceramic electrolyte

• Published in: Applied physics letters Vol. 100; no. 10; pp. 103902 - 103902-4
• Main Authors: Francisco, Brian E., Jones, Christina M., Lee, Se-Hee, Stoldt, Conrad R.
• Format: Journal Article
• Language: English
• Published: American Institute of Physics 09-03-2012
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.3693521

While today's lithium-ion batteries offer acceptable energy storage capability, they lack the ability to be cycled repeatedly more than a couple thousand times. Electrochemical capacitors, i.e., supercapacitors, are being developed whose lifetimes exceed 1×10
6
cycles and power densities surpass those of batteries by several times. Here, we present an all-solid-state supercapacitor using a Li
2
S-P
2
S
5
glass-ceramic electrolyte as both separator and ion conductor. Three device architectures are examined including two with nanostructured electrodes which incorporate multi-walled carbon nanotubes (MWCNTs). Cyclic voltammograms and electrochemical impedance measurements demonstrate that these devices develop reversible double layer capacitance, and a maximum of 7.75F/g is achieved in the device constructed by mechanically mixing the nanostructured electrodes. Electrochemical impedance spectroscopy explains non-idealities observed when MWCNTs are incorporated in the electrode layers.