Evaluation of the performance of high-specific-surface-area activated carbon from coconut shell bio-precursor in zinc-ion hybrid supercapacitor systems with fast charge/discharge capability

Document Type : Original Article

Authors
Nima Dalir 1
Ali Zeinodiny 2
1 Department of renewable energy
2 Ph.D. Candidate, Department of Physical Chemistry, Faculty of Basic Sciences, Tarbiat Modares University, Tehran, Iran
Abstract
The ever-increasing advancement of portable electronic devices and electric vehicles dramatically increases the demand for high-performance energy storage systems. Unfortunately, current technologies in this field each suffer from their own specific drawbacks. Supercapacitors suffer from low energy density, lithium-ion batteries are associated with safety hazards, and alkaline zinc/manganese dioxide batteries lack adequate stability over repeated cycles. In this research, we introduce a novel energy storage system termed zinc-ion hybrid supercapacitor (ZHS), in which activated carbon, zinc metal, and aqueous zinc sulfate solution are employed as the positive electrode, negative electrode, and electrolyte, respectively. The operation of this device is based on two reversible processes: adsorption/desorption of ions onto the surface of activated carbon at the cathode side, and deposition/dissolution of zinc ions on the metallic anode. This dual mechanism enables zinc-ion hybrid supercapacitors to repeatedly store and release electrical energy at high rates. The results demonstrate that these devices achieve a specific capacity of 100 mAh/g and favorable cycling stability. Owing to their excellent safety, fast charge/discharge capability, and ultra-long cycle life, these zinc-ion hybrid supercapacitors can be considered promising candidates for the next generation of energy storage systems.
Keywords
Zinc-ion hybrid supercapacitor
Biomass
Aqueous electrolyte
Energy storage
Subjects