Hybrid energy storage devices combining carbon-nanotube/polyaniline supercapacitor with lead-acid battery assembled through a “directly-inserted” method

Abstract

In this work, we used a new method to assemble hybrid energy storage devices, combining electrochemical capacitor with lead-acid battery. The ultrathin, flexible and low-weight carbon-nanotube/polyaniline (CNT/PANI) composite films used as supercapacitor electrodes were “directly-inserted” into a lead-acid battery in series or parallel. This quite simple and effective method is promising for large-scale industrialization as it reduces production and process complexity. The assembled hybrid devices showed notably improved properties, including a 19% increase in specific capacity, a 21% increase in specific energy or a 6% increase in specific power when compared to the conventional independent lead-acid batteries, which can be attributed to the synergic effect of batteries and supercapacitors.