High performance silicon nanowires/ruthenium nanoparticles micro-supercapacitors. (10th July 2019)

• Record Type: Journal Article
• Authors: Bencheikh, Yasmina; Harnois, Maxime; Jijie, Roxana; Addad, Ahmed; Roussel, Pascal; Szunerits, Sabine; Hadjersi, Toufik; El Hak Abaidia, Seddik; Boukherroub, Rabah
• Is Part Of: Electrochimica acta. Volume 311(2019)
• Page Start: 150
• Page End: 159
• Publication Date: 2019-07-10
• Subjects: Micro-supercapacitors -- Silicon nanowires -- Ruthenium nanoparticles -- Solid-state devices; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2019.04.083
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: The continuous increase of small electronic devices calls for small energy storage components, commonly known as micro-supercapacitors, that can ensure autonomous operation of these devices. In this work, we propose a simple and straightforward method to achieve high energy and power densities of a silicon-based micro-supercapacitor, consisting of silicon nanowires decorated with ruthenium nanoparticles (Ru/Si NWs). The Si NWs are obtained through the common vapor-liquid-solid (VLS) growth mechanism, while a simple electroless process is used to deposit Ru nanoparticles. While silicon nanostructuration allows to increase the surface area, coating with Ru NPs introduces a pseudocapacitance necessary to attain high energy and power densities. The Ru/Si NWs micro-supercapacitor exhibits a specific capacitance of 36.25 mF cm −2 at a current density of 1 mA cm −2 in a neutral Na2 SO4 electrolyte and a high stability over 25 000 cycles under galvanostatic charge-discharge at 1 mA cm −2 . A solid state supercapacitor is then fabricated with symmetric electrodes separated by a polyvinyl alcohol/sulfuric acid electrolyte. The device displays a specific capacitance of ∼18 mF cm −2 at a current density of 1 mA cm −2 and a specific power density 0.5 mW cm −2 . This solid-state nanowire device also exhibits a good stability over 10 000 galvanostatic charge-discharge cycles. Graphical abstract: Image 1 Highlights: Silicon nanowires decorated with ruthenium nanoparticles (Ru/Si NWs) are prepared. The Ru/Si NWs substrate is used to design a solid-state micro-supercapacitor. The device displays a specific capacitance of 18 mF cm −2 at 1 mA cm −2 The device exhibits a good stability over 10 000 cycles of charge-discharge cycles.