Nitrogen-Doped Carbon Material As the Electrocatalyst for Oxygen Reduction Reaction in Rechargeable Zinc-Air Flow Batteries

Abstract

Rechargeable Zn-air flow batteries are a promising candidate for grid energy storage applications. Zinc-air batteries (ZABs) have low environmental impact, and low cost, which give this system the potential to be applied for large-scale energy storage [1]. Active and durable electrocatalysts in the positive side of the ZABs are important to catalyze the oxygen reduction reaction (ORR) during discharge. N-doped carbons have been reported as a cost-effective catalyst with higher catalytic activity than Pt/C to catalyze the ORR in metal-air flow batteries [2, 3].In this study colloid imprinted carbons (CICs) and graphene-based materials were applied as the ORR catalyst to improve the performance of the zinc-air battery. Nitrogen doped CICs (NCICs) were prepared by an electropolymerization / carbonization process. Nitrogen doped graphene (NG) were prepared by an electrochemical exfoliation method. The prepared doped carbon materials were characterized by physicochemical characterization methods including SEM and XPS. To evaluate the electrocatalytic activity and the number of electrons transferred in the ORR reaction, cyclic voltammetry (CV) and rotating disk electrode (RDE) experiments were carried out in a three-electrode cell. CV and RDE experiments indicated that NG and NCICs improved the ORR activity.In this study, a flow-through cell design for the air side was applied to evaluate the performance of the air cathode of the Zn-air flow cell, operating at constant current conditions during discharge.1]Li, Yanguang, Ming Gong, Yongye Liang, Ju Feng, Ji-Eun Kim, Hailiang Wang, Guosong Hong, Bo Zhang, and Hongjie Dai. "Advanced zinc-air batteries based on high-performance hybrid electrocatalysts." Nature communications 4 (2013): 1805.[2] Lai, Linfei, Jeffrey R. Potts, Da Zhan, Liang Wang, Chee Kok Poh, Chunhua Tang, Hao Gong, Zexiang Shen, Jianyi Lin, and Rodney S. Ruoff. "Exploration of the active center structure of nitrogen-doped graphene-based catalysts for oxygen reduction reaction." Energy & Environmental Science 5, no. 7 (2012): 7936-7942.[3] Dai, Liming, Yuhua Xue, Liangti Qu, Hyun-Jung Choi, and Jong-Beom Baek. "Metal-free catalysts for oxygen reduction reaction." Chemical reviews 115, no. 11 (2015): 4823-4892.