Mitigating supercapacitor self-discharge with CNT-infused WO 3 nanoclusters and sodium alginate-based lyotropic liquid crystal

This research aims to focus on developing advanced electrode–electrolyte materials for high-performance supercapacitors with suppressed self-discharge behavior. WO 3 nanoclusters are hydrothermally synthesized with multiwalled carbon nanotubes as the electrode material. Sodium alginate (SA) and K 2 S 2 O 8 are used as composite electrolytes, which play a significant role in enhancing the electrochemical performance of supercapacitors. The structural, morphological and chemical features were thoroughly assessed, when studying the properties of SA-based lyotropic liquid crystal (LLC) materials. The electrochemical behavior of these materials was also measured, through use of standard electrochemical methods. The micelle formation and electrolyte arrangement in the SA-based LLC were investigated using Polarizing optical microscopy and dynamic light scattering studies. The optimized supercapacitor delivers a specific capacitance of 194.88 F g −1 in 70 mM LLC at a current density of 0.8 A g −1 and produced the energy density of 27.07 Wh kg −1 , with a power density of 4.872 kW kg −1 . A significant contribution of this research for enhancing the longevity and efficiency of supercapacitors is the reduction in self-discharge rates. The leakage current obtained 1.28 µ A g −1 indicating low self-discharge and good voltage retention characteristics of the device with the voltage decay rate of 1.89% h −1 . Moreover, it demonstrates impressive stability, maintaining high current retention and 90% coulombic efficiency even after 10 000 cycles. These findings emphasize the strong capability of the WO 3 /MWCNT–LLC system for next-generation supercapacitors with superior efficiency, longevity, and diminished self-discharge.