Room temperature performance of 4 V aqueous hybrid supercapacitor using multi-layered lithium-doped carbon negative electrode

Water-stable multi-layered lithium-doped carbon (LixC6) negative electrode using poly(ethylene oxide) (PEO)-lithium bis(trifluoromethansulfonyl)imide (LiTFSI) polymer electrolyte containing N-methyl-Npropylpiperidinium bis(trifluoromethansulfonyl)imide (PPI3TFSI) ionic liquid was developed. Electrochemical properties at 60 degrees C of the aqueous hybrid supercapacitor using activated carbon positive electrode and a multi -layered LixC6 negative electrode (LixC6 I PEO-LiTFSI LTAP) without PPI3TFSI exhibited performance similar to that using Li anode (Li I PEO-LiTFSI I LTAP). A drastic decrease in ESR was achieved by the addition of PPI3TFSI to PEO-LiTFSI, allowing room temperature operation. The ESR of the multi -layered LixC6 negative electrode with PEO-LiTFSI-PPI3TFSI at 25 degrees C was 801 Omega cm(2), which is 1/6 the value of the multi-layered Li negative electrode with PEO-LiTFSI (5014 0 cm(2)). Charge/discharge test of the aqueous hybrid supercapacitor using multi-layered LixC6 negative electrode with PEO-LiTFSIPPI3TFSI at 25 degrees C afforded specific capacity of 20.6 mAh (g-activated carbon)-1 with a working voltage of 2.7-3.7 V, and good long-term capability up to 3000 cycles. Furthermore, an aqueous hybrid super capacitor consisting of a high capacitance RuO2 nanosheet positive electrode and multi-layered LixC6 negative electrode with PEO-LiTFSI-PPI3TFSI showed specific capacity of 196 mAh (g-RuO2)(-1) and specific energy of 625 Wh (kg-RuO2)-1 in 2.0 M acetic acid-lithium acetate buffered solution at 25 C. (C) 2016 Elsevier B.V. All rights reserved.