Binder-Free 3D Integrated Ni@Ni₃Pt Air Electrode for Zn-Air Batteries

Developing an air electrode with high efficiency and stable performance is essential to improve the energy conversion efficiency and lifetime of zinc-air battery. Herein, Ni₃Pt alloy is deposited on 3D nickel foam by a pulsed laser deposition method, working as a stable binder-free air electrode for rechargeable zinc-air batteries. The polycrystalline Ni₃Pt alloy possesses high oxygen-conversion catalytic activity, which is highly desirable for the charge and discharge process in zinc-air battery. Meanwhile, this sample technique constructs an integrated and stable electrode structure, which not only has a 3D architecture of high conductivity and porosity but also produces a uniform Ni₃Pt strongly adhering to the substrate, favoring rapid gas and electrolyte diffusion throughout the whole energy conversion process. Employed as an air electrode in zinc-air batteries, it exhibits a small charge and discharge gap of below 0.62 V at 10 mA cm^-2, with long cycle life of 478 cycles under 10 min per cycle. Furthermore, benefitting from the structural advantages, a flexible device exhibits similar electrochemical performance even under the bending state. The high performance resulting from this type of integrated electrode in this work paves the way of a promising technique to fabricate air electrodes for zinc-air batteries.