Synergistic Bifunctional Catalyst Design based on Perovskite Oxide Nanoparticles and Intertwined Carbon Nanotubes for Rechargeable Zinc–Air Battery Applications

Abstract

Advanced morphology of intertwined core-corona structured bifunctional catalyst (IT-CCBC) is introduced where perovskite lanthanum nickel oxide nanoparticles (LaNiO3 NP) are encapsulated by high surface area network of nitrogen-doped carbon nanotubes (NCNT) to produce highly active and durable bifunctional catalyst for rechargeable metal-air battery applications. The unique composite morphology of IT-CCBC not only enhances the charge transport property by providing rapid electron-conduction pathway but also facilitates in diffusion of hydroxyl and oxygen reactants through the highly porous framework. Confirmed by electrochemical half-cell testing, IT-CCBC in fact exhibits very strong synergy between LaNiO3 NP and NCNT demonstrating bifunctionality with significantly improved catalytic activities of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Furthermore, when compared to the state-of-art catalysts, IT-CCBC outperforms Pt/C and Ir/C in terms of ORR and OER, respectively, and shows improved electrochemical stability compared to them after cycle degradation testing. The practicality of the catalyst is corroborated by testing in a realistic rechargeable zinc-air battery utilizing atmospheric air in ambient conditions, where IT-CCBC demonstrates superior charge and discharge voltages and long-term cycle stability with virtually no battery voltage fading. These improved electrochemical properties of the catalyst are attributed to the nanosized dimensions of LaNiO3 NP controlled by simple hydrothermal technique, which enables prolific growth of and encapsulation by highly porous NCNT network. The excellent electrochemical results presented in this study highlight IT-CCBC as highly efficient and commercially viable bifunctional catalyst for rechargeable metal-air battery applications.

Laminated Cross‐Linked Nanocellulose/Graphene Oxide Electrolyte for Flexible Rechargeable Zinc–Air Batteries

“…[6] However, in portable applications, their merits are largely limited by the bulky battery configurations, as a result of relying on aqueous electrolytes. [7,8] To this end, one approach is to swap aqueous electrolytes for versatile, solid-sate alternatives, making zinc-air batteries safer, lighter, and more portable. The main issues related to the solid-state electrolytes are insufficient ionic conductivity, electrolyte retention, and complex synthesis process.…”

Perovskite Electrocatalysts for the Oxygen Reduction Reaction in Alkaline Media

“…Carbon may corrode or erode at oxidative potentials [98], which is a known problem for the stability of catalyst layers made from inks or slurries. The design of perovskite-carbon hybrid systems [98][99][100][101][102] is a possible avenue to make composite electrodes more robust so that catalyst stability is decoupled from catalyst activity. Synergetic effects between carbon supports and perovskite catalysts is a very active field of research and the reader is referred to a recent review for additional discussion [98].…”

“…In terms of cost, it was estimated composite electrodes of micron-sized LaMnO 3+δ [22] and Pt have about equal activity per cost [26], so that the most active nanoparticle LaMnO 3 composite in Table 3 would be about four times cheaper as compared to the commercial Pt/C benchmark in Figure 3b, albeit at significantly increased catalyst weight. Thus, perovskite oxides have been employed in many prototype devices of fuel cells [66,144,145] and Zn-air batteries [101,102,108], which is reviewed in detail elsewhere [11,89,90].…”

Highly active Co-doped LaMnO 3 perovskite oxide and N-doped carbon nanotube hybrid bi-functional catalyst for rechargeable zinc–air batteries

“…In the first stage, procedure is outlined elsewhere in our previous report. [21] A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT 5 …”