Toward Ultrahigh-Capacity V₂O₅ Lithium-Ion Battery Cathodes via One-Pot Synthetic Route from Precursors to Electrode Sheets

Acquisition of high-energy density is the highest priority requirement and unending challenge in energy storage systems including lithium-ion batteries (LIBs). One theoretically preferable way to reach this goal is the use of cathode active materials such as vanadium pentoxide (V₂O₅) that relies on multielectron insertion/extraction reactions. Application of V₂O₅ to LIB cathodes, however, has been mostly focused on V₂O₅ materials themselves with little emphasis on V₂O₅-incorporated cathode sheets. Here, as an unusual electrode-architecture approach to achieve ultrahigh-capacity V₂O₅ cathode sheets, a new class of self-standing V₂O₅ cathode sheets is demonstrated based on V₂O₅/multiwalled carbon tubes (MWNTs) mixtures spatially besieged by polyacrylonitrile nanofibers (referred to as “VMP cathode sheets”). Notably, the VMP cathode sheet is fabricated directly via one-pot synthetic route starting from V₂O₅ precursor (i.e., through concurrent electrospraying/electrospinning followed by calcination), without metallic foil current collectors/carbon powders/polymeric binders. The one-pot synthesis allows dense packing of V₂O₅ nanoparticles in close contact with MWNT electronic networks and also formation of well-developed interstitial void channels (ensuring good electrolyte accessibility). This material/architecture uniqueness of the VMP cathode sheet eventually enables significant improvements in cell performance (particularly, gravimetric/volumetric capacity of cathode sheets) far beyond those accessible with conventional electrode technologies.