Novel Hydrogel-Derived Bifunctional Oxygen Electrocatalyst for Rechargeable Air Cathodes

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Commercialization of zinc-air batteries is hindered by the absence of efficient, cost-effective bifunctional catalysts for oxygen reduction and evolution reactions.
• Existing catalysts often lack the required activity, durability, or cost-efficiency for widespread adoption.

Purpose of the Study:

• To develop and evaluate novel bifunctional catalysts for rechargeable zinc-air batteries.
• To address the limitations of current catalysts by creating a highly active and durable material.

Main Methods:

• Synthesis of NiCo nanoparticles anchored on porous fibrous carbon aerogels (NiCo/PFC aerogels) using a novel K2Ni(CN)4/K3Co(CN)6-chitosan hydrogel-derived method.
• Electrocatalytic performance testing of NiCo/PFC aerogels as air-cathode catalysts in rechargeable Zn-air batteries.

Main Results:

• NiCo/PFC aerogels demonstrated excellent bifunctional catalytic activity for oxygen electroreduction and evolution.
• The developed Zn-air battery with NiCo/PFC aerogels exhibited stable cycling for 600 hours (300 cycles) at 10 mA cm-2, significantly outperforming Pt/C+IrO2 catalysts.
• The round-trip overpotential showed only a minor increase during extended cycling.

Conclusions:

• NiCo/PFC aerogels represent a promising, cost-effective, and highly durable bifunctional catalyst for rechargeable Zn-air batteries.
• The novel synthesis method provides a scalable route to advanced electrocatalyst materials.
• These findings pave the way for the commercial viability of high-performance Zn-air energy storage systems.