One-pot synthesis of N,S-doped pearl chain tube-loaded Ni3S2 composite materials for high-performance lithium–air batteries

Abstract

To improve the high reversibility of lithium–air batteries, an air electrode needs to have excellent electrochemical performance and spatial structure. Ni₃S₂ nanoparticles are loaded onto an N,S-doped pearl chain tube (N,S-PCT) by a method called quasi-chemical vapor deposition (Q-CVD). Additionally, N and S are doped during the synthesis process, thereby forming an ideal pipe rack-like structure. The large amount of space in the tube rack can provide sufficient storage to act as a buffer for the discharge products, and the interconnected tubes can effectively promote the dispersion of O₂ and electrolyte. The addition of Ni₃S₂ nanoparticles effectively reduces the charge transfer resistance, thereby increasing the electron mobility of the cathode. Ni₃S₂@N,S-PCT cathodes effectively improve the cycling and high-rate performance of lithium–air batteries, demonstrating an ultrahigh discharge capacity of 16 733.7 mA h g⁻¹ at a current density of 400 mA g⁻¹ and an ultrahigh discharge capacity of 5088.1 mA h g⁻¹ at a current density of 1000 mA g⁻¹. When the cut-off capacity is 1000 mA h g⁻¹, the battery with the Ni₃S₂@N,S-PCT-800 electrode can achieve cycling stability for 148 cycles. This research provides a new solution for the design of lithium–air batteries with high electrocatalytic performance.