Hierarchical Porous N-Doped Carbon Nanofibers with Encapsulated Li3VO4 Nanoparticles for Lithium-Ion Storage

Lithium vanadium oxide (Li3VO4) is a highly promising anode material for lithium-ion batteries due to its high theoretical capacity and moderate operation voltage. However, its low intrinsic electronic conductivity leads to an undesirable rate capability and restricts its practical applications. To address this issue, we designed a structure of hierarchical porous carbon network-wrapped Li3VO4 nanoparticles to enhance the overall electrochemical performance, especially at high rates. Polyacrylonitrile (PAN) and poly(methyl methacrylate) (PMMA) were employed as carbon sources and porous templates during the electrospinning and subsequent calcination processes. This approach can enhance the electronic conductivity, improve the contact area between Li3VO4 and the electrolyte, and decrease the ion/electron diffusion path. As a result, the constructed hierarchical porous N-doped C nanofiber-encapsulated Li3VO4 nanoparticles (P-LVO/NC NFs) exhibited an ultrahigh discharge capacity of 1039.5 mA h g–1 and a stable capacity of 736.8 mA h g–1 after 500 cycles at 0.5 A g–1. Furthermore, they demonstrated an outstanding rate capability of 397.7 mA h g–1 and at 5.0 A g–1. The unique hierarchical porous structure provided excellent reaction kinetics, resulting in exceptional Li-ion storage performance. Therefore, the fabricated P-LVO/NC NFs hold great potential as high-performance anode materials.