Enhanced Specific Capacitance of Self-Assembled Three-Dimensional Carbon Nanotube/Layered Silicate/Polyaniline Hybrid Sandwiched Nanocomposite for Supercapacitor Applications

Platelike montmorillonite (known as nanoclay), with ∼1 nm thick aluminosilicate layers, is the most common layered silicate used because of its availability and environment-friendly nature. With the increasing demand for cheaper and eco-friendly materials for energy storage applications, these layered silicates could be explored as a suitable candidate. In this work, a series of self-assembled three-dimensional electrode materials for supercapacitors have been synthesized from carbon nanotubes (CNTs), Cloisite 30B, and polyaniline (PANI) by both in situ and ex situ approaches. The role of the layered silicate in the electrochemical performance of these electrode materials has been explored. Morphological studies revealed the successful coating of PANI over the CNTs and silicate layers of the Cloisite 30B and the development of a self-assembled three-dimensional porous sandwichlike structure. With the incorporation of layered silicate, the morphology was observed to be highly porous with an enhanced electroactive surface that permits easy access of the electrolyte toward improved electrochemical performance. A 28% increase in specific capacitance with respect to the CNT/PANI nanocomposite was achieved with the ex situ addition of Cloisite 30B, which increased to 110% for the in situ product. The sample retained about 92% of its initial specific capacitance after 2000 cycles. Similar capacitance performance results were also documented from galvanostatic charging-discharging analysis at 5A/g. All of these results demonstrate the promising behavior of the developed electrode material for supercapacitor applications.