Efficient Co–Ni oxysulfide nanoarchitectured materials for long-lasting electrochemical cells: Biodegradable parafilm assisted pouch-type cells for portable electronic applications

Abstract

An advance of highly efficient transition metal chalcogenides-based electroactive material for electrochemical cells (ECCs) is of high significance for endorsing large-scale sustainable fabrication of energy storage devices. Herein, the binary metal chalcogenide fish scales-like structures (FSSs) were directly grown on the conductive current collector (nickel foam) using a single-step sulfurization process. In this process, the reaction temperature plays a key role in generating the cobalt-nickel oxyhydroxide (Co–Ni)OH FSSs at a constant reaction time. As result, the as-designed (Co–Ni)OH-140 exhibited higher electrochemical performance than the other ones prepared at different reaction temperatures (i.e., 120 and 160 °C). Furthermore, the sulfur (S) dopant suggestively not only enhances the electrical conductivity but also improves the electrochemical performance of the electrode. The resulting Co–Ni oxysulfide ((Co–Ni)OS) FSS electrode exhibited significantly improved electrochemical activity with outstanding cycling retention of 116% even after 20000 cycles. Moreover, by utilizing the charge storage properties of the (Co–Ni)OS FSS electrode, an ECC was assembled, which is fabricated by using a biodegradable parafilm as the pouch. The as-fabricated ECC exhibited maximum areal/specific energy density (0.44 mWh cm −2 /65.9 Wh kg −1 ) and power density (51.5 mW cm −2 /7.6 kW kg −1 ) with a high rate capability of 59.1% even at a higher current density of 60 mA cm −2 . Furthermore, the self-powering work station with the wind turbine for energy conversion and the ECCs for charge storage was designed to drive portable electronic devices. The simple and cost-effective strategies of hierarchically connected nanomaterials provide a new path for the development of high-efficient ECCs. Synopsis: Binder-free metal chalcogenides-based nano active materials are designed using a single-step hydrothermal approach, followed by the sulfurization process. To assemble the electrochemical cell, biodegradable parafilm is used as the pouch-like bag to store energy, which can be stored from the wind energy to operate the real-time electronic appliances.