Enhanced Electrochemical Performance of CuO Capsules@CDs Composites for Solid-State Hybrid Supercapacitor

Abstract

Capsule-like CuO/CDs (CuO@CDs) with a surface area of 33.12 m2 g–1 were synthesized by the hydrothermal treatment, compared to 19.02 m2 g–1 for pristine CuO. An anode was then fabricated from capsule-like CuO@CDs to form a hybrid solid-state supercapacitor (HSSC) with the activated carbon (AC) cathode and PVA/1M KOH as an electrolyte. Three electrode system offered 1208.88 F/g (specific capacitance at 2 A/g current density) and unveiled a remarkable life cycle (retention) and Coulombic efficiency (CF): 93 and 98% after 5000 charge–discharge cycles at 10 A/g. In terms of performance, the HSSC delivered 1.5 V and 102.60 F/g (50.74 C/g) at 2 A/g, 8437.50 W/kg (power density), and 36.90 Wh/kg (energy density). The HSSC still retained 92% of cyclic stability and 83% of CF after 10,000 cycles.

Review of Battery-type Transition Metal (Cu, Co, and Ni) Oxide Based Electrodes: From Fundamental Science to Fabrication of a Hybrid Supercapacitor Device

“…The carbon dots being 0 D in nature exhibit high surface area and elevated electrochemical activity. As reported the binary composite of carbon dots decorated copper oxide shows a specific capacitance value of 1200 F g –1 at a current density of 2 A g –1 Table shows the electrochemical behavior of the various copper-based supercapacitors.…”

“…Recently pristine copper oxide and its composites have been synthesized using MOF as a template, using hydrothermal treatment with the aid of urea and polyethylene glycol as shape directing agents. − MOF derived Cu displays a specific capacitance of 451C g –1 at a sweep rate of 3 mV s –1 . Nickel doped CuCo 1.5 Ni 0.5 S 4 nanoneedles grown on Ni foam electrodes shows a specific capacitance of 326 mAh g –1 at a current density of one A g –1 .…”

A Comprehensive Review of Ammonium Ion Hybrid Supercapacitors: Exploring Recent Breakthroughs and Future Horizons

“…These HSCs feature two distinct types of electrodes: one functioning as a pseudocapacitive or battery-type cathode and the other as a capacitor-type anode. Moreover, an insulated separator is positioned between the cathode and anode to prevent short circuits resulting from direct electrode contact, allowing only the facile movement of ammonium ions. , Consequently, depending on the chosen materials, the hybrid device demonstrates both electric double-layer capacitance (EDLC) and pseudocapacitive mechanisms attributed to the anode and cathode, respectively. − …”