Elucidating the synergy of layer-by-layer TMDC-TMN deposition for superior electrochemical performance in supercapattery devices

Supercapatteric devices can combine the advantages of batteries and supercapacitors, addressing their individual limitations in power and energy density. This study focuses on enhancing the electrochemical performance of battery-grade electrodes through the strategic incorporation of transition metal dichalcogenides and transition metal nitrides, specifically tungsten disulfide. Utilizing the magnetron sputtering, we integrated conductive layers of chromium nitride and titanium nitride between substrate and WS 2 . Results of thorough electrochemical testing revealed that the initial specific capacity (Q s ) of WS 2 was 600 C/g. However, by incorporating interfacial layers of CrN and TiN, the Q s was significantly improved 830 C/g and 1230 C/g, demonstrating the substantial impact of interface engineering on overall performance of WS 2 . The fabricated supercapatteric devices, demonstrated exceptional performance, with WS 2 /CrN//AC achieving Q s of 950 C/g and WS 2 /TiN//AC reaching a Q s of 1100 C/g. Moreover, WS 2 /CrN//AC and WS 2 /TiN//AC attained power densities of 6800 W/kg (with 99.8 % capacity retention) and 7108 W/kg (with 99.9 % capacity retention), respectively, and energy densities of 98 Wh/kg and 135 Wh/kg, highlighting the superior performance and stability of WS 2 /TiN//AC. Additionally, for examining the diffusive and capacitive behaviors of devices, two different semi-empirical models were further used and compared. This work emphasizes the potential of interface engineering in enhancing the performance of hybrid energy storage (HES) systems. • A binder free magnetron sputtering technique was employed to fabricate the electrodes. • Interface engineering was used to improve the electrochemical performance of positrode. • Transition metal nitrides were used as an interlayer between substrate and WS 2 . • The devices WS 2 /CrN//AC device delivered high energy and power density of 98 Wh/kg and 6800 W/kg. • The WS 2 /TiN//AC device demonstrated high energy and power density of 135 Wh/kg and 7108 W/kg