Research Article 2018, 9(4) 234-240 Advanced Materials Letters Copyright © 2018 VBRI Press 234 Ternary hybrid electrode material based on polyaniline/carbon nanohorn/TiO 2 with high performance energy storage capacity Sandip Maiti # , Sumanta K. Karan # , Amit K. Das, Ranadip Bera and Bhanu B. Khatua* Materials Science Centre, Indian Institute of Technology Kharagpur, Kharagpur 721302, India *Corresponding author DOI: 10.5185/amlett.2018.1763 www.vbripress.com/aml Abstract Renewable energy is very much demanding in modern time. Herein, we have discussed energy storage performance of polyaniline (PANI) and carbon nanohorn (CNH) decorated titanium dioxide (TiO2) nanoparticle, high performance electrode material. This high performance energy storage material was prepared through simple and cost effective method via in-situ polymerization of aniline in presence of CNH and TiO2 nanoparticles. Thus, as prepared active electrode material provide high specific capacitance value of 1068 F/g at current density of 3 A/g. The existence TiO2 nanoparticle in the ternary hybrid leads to enhancement of capacitance value through synergistic effect compared to the pure components (e.g., PANI and CNH are 335 F/g and 240 F/g, respectively at same current density). As morphological analysis says, TiO2 nanoparticles are observed to be coated by CNH nanofiller and PANI fiber in the hybrid, which plays a key role to enhance the capacitance value of hybrid making it highly promising electrode material for energy storage in next generation power supply. Copyright © 2018 VBRI Press. Keywords: Supercapacitor, polymer hybrid composite, high energy storage, polyaniline, carbon nanohorn, TiO2 Introduction Renewable energy is most promising energy source in present time due to lack of fossil fuels. For alternating energy source, researchers are highly concentrated on supercapacitor electrode materials for their high performance activities [1-3]. Due to high power density, fast charging/discharging ability, high cyclic efficiency, supercapacitor electrode materials are hugly accepted in modern high performance digital area [4,5]. Thus, supercapacitor materials have been alternative energy source for portable devices, electronics cars, and electronics gazettes etc. Electrical double-layer capacitors (EDLCs) and pseudocapacitors are basically two different types of supercapacitors, for developing energy [6,7]. Among them, pseudocapacitors are considered most promising and futurities energy storage electrode material for their high performance activities. Several research works are already reported on the conducting polymer or carbon nanofiller based supercapacitor materials [8-17]. In this case, active electrode materials will perform both as EDLC and pseudocapacitor which will enhance the supercapacitor performance significantly [18-22]. Among transition metal oxides, TiO2 nanoparticles have attracted attention for energy storage due to its long-term thermodynamic stability, strong oxidizing power and non- toxicity. TiO2 nanoparticle based supercapacitor electrode materials reported earlier. However, they will not achieve high capacitance value. For instance, Zhang et al. [23] prepared multifunctional TiO2/graphene nanocomposites hydrogel by facile one-pot hydrothermal method. They reported the specific capacitance value of the nanocomposite as 206.7 F/g at 0.5 A/g current density. Ramadoss et al. [24] reported hydrothermal fabrication of porous two-dimensional (2D) reduced grapheme oxide/ TiO2 nanorod array/reduced graphene oxide (rGO/TiO2 NR/rGO) which delivers 114.5 F/g at scan rate of 5 mV/s. Sun et al. [25] have studied the electrochemical properties of TiO2/graphene composites which show specific capacitance value of 84 F/g at 10 mV/s scan rate. Deshmukh et al. [26] have synthesized Fe3O4/SWCNH nanocomposites and obtained the specific capacitance value of 377 F/g at the current density of 1A/g. In this present study, we report the synthesis and electrochemical characterization of hybrid electrode material (PTC) with high energy storage capacity. This work is combination of pseudocapacitive behavior of TiO2 nanoparticle and PANI along with the double layer capacitance of CNH. The ternary hybrid was synthesized through in-situ polymerization of aniline in presence of conducting CNH and TiO2 nanoparticles. The reason behind the choosing of CNH is that it has large surface area with high aspect ratio, inherent micropores at interstitial sites, high electrical conductivity, excellent porosity and considerable internal nanospace. In the hybrid material, TiO2 nanoparticles are coated by