Rational construction of Na₃V₂(PO₄)₃ nanoparticles encapsulated in 3D honeycomb carbon network as a cathode for sodium-ion batteries

Developing suitable electrode materials with large-sized tunnel structure and fast ion diffusion pathways still is a huge challenge for sodium-ion batteries due to the larger ionic radius of sodium. Na₃V₂(PO₄)₃ nanoparticles encapsulated in three-dimensional (3D) honeycomb carbon network (3DHN-NVP) were designed and prepared via a novel sol-gel template method. When evaluated as a promising cathode for rechargeable sodium-ion batteries, the resultant 3DHN-NVP displays better electrochemical performance in terms of cycling stability, and rate capability compared to pristine NVP. This good performance can be ascribed to the 3D honeycomb carbon network in enhancing the electronic conductivity, shortening path lengths for electron transport, and alleviating the volume changes of electrode materials.