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 (V 2 O 5 ) that relies on multielectron insertion/extraction reactions. Application of V 2 O 5 to LIB cathodes, however, has been mostly focused on V 2 O 5 materials themselves with little emphasis on V 2 O 5 ‐incorporated cathode sheets. Here, as an unusual electrode‐architecture approach to achieve ultrahigh‐capacity V 2 O 5 cathode sheets, a new class of self‐standing V 2 O 5 cathode sheets is demonstrated based on V 2 O 5 /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 V 2 O 5 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 V 2 O 5 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.