Great efforts have been focused on exploring high-efficiency and stable catalysts towards oxygen reduction reaction (ORR) and reducing the use of polymer binders in cathodes for metal-air batteries. In consideration of synergistic effects, unique porous structure and improved properties, a composite of carbon nanotubes and three-dimensional graphene (CNTs-3D graphene) developed via a well-controlled route is urgently required. Herein, an ultrathin Co₃O₄ nanosheet clusters anchored on nitrogen-doped carbon nanotubes/3D graphene (NCNTs/3D graphene) composite was prepared by chemical vapor deposition (CVD) along with thermal treatments over a Ni foam substrate. The cyclic voltammetry (CV) and linear sweep voltammograms (LSVs) results indicate that the Co₃O₄/NCNTs/3D graphene composite possesses remarkable electrocatalytic performance towards ORR in alkaline condition compared with NCNTs/3D graphene, Co₃O₄/3D graphene, and 3D graphene catalysts, even outperforming the commercial 20 wt% Pt/C catalyst. Moreover, the Al-air coin cell employing Co₃O₄/NCNTs/3D graphene as binder-free cathode obtains an open circuit voltage of 1.52 V, a specific capacity of 482.80 mAh g⁻¹ at the discharge current density of 1.0 mA cm⁻², and a maximum power density (P_max) of 4.88 mW cm⁻², which are superior to the Al-air coin cell using Co₃O₄/3D graphene, Pt/C, and traditional Co₃O₄/NCNTs/3D graphene electrodes. This work supplies valuable insights to develop scalable binder-free cathodes using NCNTs/3D graphene based electrocatalysts with excellent catalytic activity towards ORR in Al-air systems.

人们一直致力于研究高效，稳定的催化剂以进行氧还原反应（ORR），并减少聚合物粘合剂在金属-空气电池阴极中的使用。考虑到协同效应，独特的多孔结构和改进的性能，迫切需要通过良好控制的路线开发的碳纳米管和三维石墨烯（CNTs-3D石墨烯）的复合材料。在此，通过化学气相沉积（CVD）以及在Ni泡沫衬底上的热处理，制备了锚固在氮掺杂的碳纳米管/ 3D石墨烯（NCNTs / 3D石墨烯）复合材料上的超薄Co ₃ O ₄纳米片簇。循环伏安法（CV）和线性扫描伏安图（LSVs）结果表明，Co ₃ O与NCNTs / 3D石墨烯，Co ₃ O ₄ / 3D石墨烯和3D石墨烯催化剂相比，₄ / NCNTs / 3D石墨烯复合材料在碱性条件下对ORR具有出色的电催化性能，甚至优于20 wt％的Pt / C催化剂。此外，使用Co ₃ O ₄ / NCNTs / 3D石墨烯作为无粘合剂阴极的铝制空气硬币电池在1.0 mA cm的放电电流密度下获得1.52 V的开路电压，482.80 mAh g ^-1的比容量。^-2和最大功率密度（P _max）为4.88 mW cm ^-2，优于使用Co ₃ O _4的铝制纽扣电池/ 3D石墨烯，Pt / C和传统的Co ₃ O ₄ / NCNTs / 3D石墨烯电极。这项工作提供了宝贵的见识，以开发具有可伸缩性的无粘结剂阴极，该阴极使用基于NCNTs / 3D石墨烯的电催化剂，对Al-空气系统中的ORR具有出色的催化活性。