Tailoring the nanostructure and composition of transition metal nitrides is highly important for their use as potent low-cost electrocatalysts. Cobalt nitride (CoN) exhibits strong catalytic activity for oxygen evolution reaction (OER). However, its poor catalytic efficiency for oxygen reduction reaction (ORR) hinders its application in rechargeable zinc-air batteries (ZABs) as the air cathode. In this work, we deploy the effective strategy of Mn doping to improve both OER and ORR activity of CoN nanowires as the cathode material for ZAB. Theoretical calculation predicts that moderate Mn doping in cobalt nitride results in a downshift of the d-band center and reduces the adsorption energy of reaction intermediates. With ∼10 at% Mn dopants, stronger catalysis activities for both OER and ORR are achieved compared to pure CoN nanowires. Subsequently, both aqueous and flexible quasi-solid-state ZABs are constructed using the Mn-doped CoN nanowires array as additive-free air cathode. Both types of devices present large open circuit potential, high power density and long-cycle stability. This work pushes forward the progress in developing cost-effective ZABs.

调整过渡金属氮化物的纳米结构和组成对于将其用作有效的低成本电催化剂非常重要。氮化钴（CoN）对氧气析出反应（OER）表现出强大的催化活性。但是，其氧还原反应（ORR）的催化效率差，阻碍了其在作为空气阴极的可充电锌空气电池（ZAB）中的应用。在这项工作中，我们部署了锰掺杂的有效策略，以提高作为ZAB阴极材料的CoN纳米线的OER和ORR活性。理论计算预测，氮化钴中适度的Mn掺杂会导致d带中心的下移并降低反应中间体的吸附能。与纯CoN纳米线相比，使用约10 at％的Mn掺杂剂，对OER和ORR都具有更强的催化活性。后来，水性和柔性准固态ZAB都是使用Mn掺杂的CoN纳米线阵列作为无添加剂的空气阴极来构造的。两种类型的设备都具有大的开路电位，高功率密度和长周期稳定性。这项工作推动了开发具有成本效益的ZAB的进展。