A Multi-Interfacial Material Design Leading Bifunctional Oxygen Reduction and Water Oxidation Electrocatalysis to Zinc–Air Battery Application
SK Tarik Aziz, Anshu Kumar, Mahendra Kumar Awasthi, Yashwant Pratap Kharwar, Imran Karajagi, Vikram Vishal, Prakash C. Ghosh, Deepak P. Dubal, Arnab Dutta
Abstract
The presence of an energy efficient and stable electrocatalyst capable of inflicting a bidirectional oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is vital for the proper functioning of a rechargeable zinc–air battery (ZAB). Here, we rationally combined ORR-active nitrogen-doped graphitic carbon (N@C) around an OER-inflicting Ce-doped Ni–Co layered double hydroxide (LDH) to generate a unique N@C_LDH-CeO 2 material, where all the segments operate synergistically to display bidirectional ORR/OER activity under analogous conditions. This multi-interfacial N@C_LDH-CeO 2 material displayed exceptional energy efficiency, which was measured by its relatively low potential difference (Δ E ) of 0.74 V between the half-wave potential of ORR ( E 1/2 ) and the OER potential at a current density of 10 mA cm –2 ( E j@ 10 ). This material was active in a ZAB assembly, achieving one of the highest reported specific energies (894.3 Wh kg –1 of Zn), appreciable power density (243 mW cm –2 ), and excellent specific capacity (698 mAh g –1 @ 10 mA cm –2 ), along with a remarkable durability of 270.0 h for 1600 continuous cycles. The tactical presence of N- and Ce-doping modulated the ORR and OER activity, respectively, as N@C_LDH-CeO 2 displayed ample active sites during electrocatalysis on either side. This material remains active even in a solid-state ZAB assembly, where it successfully transduces energy to an electronic device.