Transition metal-assisted layer-by-layer binder free deposition for high-performance energy storage devices

Abstract

The increasing energy demands of the world necessitate the development of advanced energy storage systems. Hybrid supercapacitors (HSCs) have emerged as promising candidates, combining the high specific power density (P_S) of supercapacitors (SCs) with the high specific energy density (E_S) of batteries (BATs). However, its performance is dependent on the properties of electrode materials, which need enhancements in conductivity, surface area, and electrochemical stability. In this study, we utilized magnetron sputtering technique for exploring the potential of interface engineering to improve the electrochemical performance of tungsten disulfide (WS₂) as a battery grade electrode material by incorporating chromium (Cr) and titanium (Ti) as an interfacial layer. This strategic modification significantly increased the conductivity, charge transfer efficiency, and structural stability of the WS₂ electrode. Electrochemical experimentation in both half-cell and full-cell configurations revealed that the WS₂/Cr and WS₂/Ti electrode exhibits superior C_S [2400 and 3800] F/g, respectively compared to pristine WS₂. Fabricated WS₂/Cr//AC and WS₂/Ti//AC attained E_S [95 and 117] Wh/kg and P_S [6800 and 8500] W/kg, respectively. The outcomes from the electrochemical testing further demonstrated the superior cyclic stability of WS₂/Cr//AC and WS₂/Ti//AC with [96.5 and 98.3] % which shows that Cr and Ti as an interfacial layer not only mitigates the limitations of WS₂ but also enables the devices to achieve higher performance metrics, underscoring the critical role of interface engineering in advancing HSCs technologies.