Structural Characterization and Electrochemical Performance of Titanium Diboride (TiB2) Powders Synthesized by Citrate Gel Method

This study reports synthesis of titanium boride (TiB₂) powders and their structural characterization and electrochemical performance for a potential electrode material for supercapacitors, employing the citrate gel method within a cost-effective solution-based process. Boric acid, titanium isopropoxide, and citric acid are utilized as precursors for the synthesis route. Preceramic powders obtained from the solution undergo heat treatment at 1400 and 1500 °C in an argon atmosphere. The synthesized powder is subjected to structural and morphological characterization through X-ray diffraction, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, differential thermal analysis-thermogravimetry, fourier-transform infrared spectroscopy, and raman spectroscopy measurements. Phase analysis reveals the formation of TiB₂. Scanning electron microscopy and transmission electron microscopy images clearly show that TiB₂ is obtained as a well-defined hexagonal plate-shaped morphology having side lengths of 300–700 nm and thicknesses of ≈12 nm. TiB₂ is used as electrode material in both symmetric and asymmetric devices. For asymmetric configuration, graphite, active carbon, and multilayer carbon nanotube powders are used as the counter electrode. Cyclic voltammetry, potentiostatic electrochemical impedance spectroscopy, and galvanostatic cycling with potential limitation are performed using the multichannel potentiostat. TiB₂ delivers an energy density of 0.0028 Wh kg⁻¹ at a power density of 113.3 W kg⁻¹.