Ultrahigh performance supercapacitors utilizing core-shell nanoarchitectures from a metal-organic framework-derived nanoporous carbon and a conducting polymer.

Abstract

Hitherto, many reports on composite materials for electrochemical applications are based on one-dimensional carbon nanotubes or two-dimensional graphene materials. However, these composite materials usually suffer from a stacking problem during electrochemical cycling. A smart nanoarchitectural design is needed for composite materials in order to overcome this problem. Recent research on electrochemical energy storage (EES) applications has focused on the development of three-dimensional (3-D) core-shell structures. The basis for high performance electrochemical energy storage is to control the efficient intercalation of ions in such a 3-D structure. Here, we demonstrate controlled synergy between the physicochemical properties of nanoporous carbon and conducting polyaniline polymer (carbon-PANI), which leads to some new interesting electrochemical properties. The time-dependent controlled optimization of the core-shell nanocomposites consisting of nanoporous carbon with a thin layer of PANI nanorod arrays gives useful control over supercapacitor performance. Furthermore, these carbon-PANI nanocomposites can electrochemically access ions with remarkable efficiency to achieve a capacitance value in the range of 300-1100 F g-1. When assembled in a two electrode cell configuration, the symmetric supercapacitor (SSC) based on carbon-PANI//carbon-PANI shows the highest specific energy of 21 W h kg-1 and the highest specific power of 12 kW kg-1. More interestingly, the SSC shows capacitance retention of 86% after 20 000 cycles, which is highly superior compared to previous research reports.