Capacitive vs Faradaic Energy Storage in a Hybrid Cell with LiFePO 4 /RGO Positive Electrode and Nanocarbon Negative Electrode

Abstract

© The Author(s) 2016. Published by ECS. We report an advanced device based on a Nitrogen-doped Carbon Nanopipes (N-CNP) negative electrode and a lithium iron phosphate (LiFePO4) positive electrode. We carefully balanced the cell composition (charge balance) and suppressed the initial irreversible capacity of the anode in the round of few cycles.We demonstrated an optimal performance in terms of specific capacity 170 mAh/g of LiFePO4 with energy density of about 203 Wh kg-1 and a stable operation for over 100 charge-discharge cycles. The components of this device (combining capacitive and faradaic electrodes) are low cost and easily scalable. This device has a performance comparable to those offered by the present technology of LIBs with the potential for faster charging; hence, we believe that the results disclosed in this work may open up new opportunities for energy storage devices.