Sonochemical synthesis of welded titanium dioxide-silver nanocomposite as a 3-dimensional direct ink writing printed cathode electrode material for high-performance supercapacitor

Using a facile ultra-sonication method, Ag nanoparticles are embedded into TiO₂ nanoparticles, and the as-developed composite material is 3D printed through direct ink writing (DIW) process as an electrode material for supercapacitor. The as-printed TiO₂–Ag composite electrode displayed a lower contact angle value of 32.2°, with higher surface energy of 76.32 mJ m⁻². The electrochemical performance of the TiO₂ nanoparticles incorporated with silver nano-powder is improved significantly in-comparison to pristine TiO₂ nanoparticles. The significant improvement in the electrochemical performance of the TiO₂ nanoparticles with the incorporated silver nano-powder is due to the synergistic interaction between the TiO₂ nanoparticles and the silver nano-powder developed through sonochemical process. The plain TiO₂ and TiO₂–Ag composite printed electrode revealed a maximum specific capacitance (specific capacity) values of 148.43 (56.84 mA h mg⁻¹) and 257.8 (122.96 mA h mg⁻¹) F g⁻¹ at 1 A g⁻¹, respectively. TiO₂–Ag composite printed electrode also maintained a capacitance retention of 58.3% at a higher current density of 10 A g⁻¹. The electrochemical impedance spectroscopy study also confirms that the incorporation of silver nano-powder into TiO₂ nanoparticles reduces charge transfer resistance (R_ct). The TiO₂–Ag nanocomposite electrode shows excellent long-term cycling stability with 96% of capacitance retention after 3,000 continuous GCD cycles. Moreover, TiO₂–Ag//AC based asymmetric supercapacitor device is developed which delivers a high energy density of 26.72 W h Kg⁻¹ at minimum power density of 655.61 W kg⁻¹. These results indicate a high potential of the as-printed TiO₂–Ag composite electrode material for energy storage applications.