A High Surface Area Carbon‐coated 3D Nickel Nanomesh for Li‐O₂ Battery

: Nanostructured electrodes show great promises for application in batteries and could improve their energy and power density. Herein, a carbon-coated 3D Ni nanomesh was used as an air cathode for non-aqueous Li-air (O2 ) battery applications. A 3 μm thick 3D Ni nanomesh was fabricated, showing an excellent surface area/footprint area ratio (90 cm2 :1 cm2 ) and uniformly distributed pores, on which a conformal amorphous carbon coating was applied for the first time. This carbon-coated 3D Ni nanomesh showed an approximately 100 times larger charge-footprint capacity than that of the glassy carbon electrode. Owing to its tunable properties, a capacity higher than 6 mAh cm-2 could be achieved for a carbon-coated 3D Ni nanomesh with a thickness of 100 μm, whereas the practical capacities of current air electrodes are in the range of 2 mAh cm-2 .