Pyrophosphate Na2CoP2O7Polymorphs as Efficient Bifunctional Oxygen Electrocatalysts for Zinc-Air Batteries

Gond, R and Singh, S and Zhao, X and Singh, D and Ahuja, R and Fichtner, M and Barpanda, P (2022) Pyrophosphate Na2CoP2O7Polymorphs as Efficient Bifunctional Oxygen Electrocatalysts for Zinc-Air Batteries. In: ACS Applied Materials and Interfaces .

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Abstract

eveloping earth-abundant low-cost bifunctional oxygen electrocatalysts is a key approach to realizing efficient energy storage and conversion. By exploring Co-based sodium battery materials, here we have unveiled nanostructured pyrophosphate Na2CoP2O7 polymorphs displaying efficient bifunctional electrocatalytic activity. While the orthorhombic polymorph (o-NCPy) has superior oxygen evolution reaction (OER) activity, the triclinic polymorph (t-NCPy) delivers better oxygen reduction reaction (ORR) activity. Simply by tuning the annealing condition, these pyrophosphate polymorphs can be easily prepared at temperatures as low as 500 °C. The electrocatalytic activity is rooted in the Co redox center with the (100) active surface and stable structural framework as per ab initio calculations. It marks the first case of phospho-anionic systems with both polymorphs showing stable bifunctional activity with low combined overpotential (ca. ∼0.7 V) comparable to that of reported state-of-the-art catalysts. These nanoscale cobalt pyrophosphates can be implemented in rechargeable zinc-air batteries.

Item Type:	Journal Article
Publication:	ACS Applied Materials and Interfaces
Publisher:	American Chemical Society
Additional Information:	The copyright for this article belongs to the American Chemical Society.
Keywords:	Calculations; Cobalt compounds; Electrocatalysts; Electrolysis; Electrolytic reduction; Oxygen; Sodium compounds; Zinc compounds, Bi-functional; Bifunctional electrocatalysts; Cobalt pyrophosphate; DFT calculation; Electrocatalytic activity; Energy storage and conversions; Low-costs; Oxygen reduction reaction; Reaction activity; Zinc-air battery, Zinc air batteries
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	06 Oct 2022 10:51
Last Modified:	06 Oct 2022 10:52
URI:	https://eprints.iisc.ac.in/id/eprint/77235

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