Hollow Ni–NiO nanoparticles embedded in porous carbon nanosheets as a hybrid anode for sodium-ion batteries with an ultra-long cycle life

Abstract

As a candidate of the next-generation rechargeable batteries, sodium-ion batteries (SIBs) have attracted great interest owing to the high abundance, low cost and environmental benignity of sodium resources. However, a shortage of appropriate anode materials with superior electrochemical performance has become the major bottleneck for their future development. Here, a unique hybrid material of hollow Ni–NiO nanoparticles embedded in porous carbon nanosheets (PCNs) was fabricated through a facile in situ synthesis strategy. As an anode in SIBs, the as-fabricated Ni–NiO/PCN electrode shows an ultra-long cycle life (a nearly unvarying capacity of 235.4 mA h g⁻¹ at a current density of 1 A g⁻¹ even after 5000 cycles), which originates from the synergistic effect of high-content carbon, interconnected PCNs, metallic Ni phase, and hollow Ni–NiO nanoparticles. This work provides a promising strategy for rationally developing novel electrode materials for advanced energy storage devices.