Toward Ultrahigh-Capacity V sub(2)O sub(5) Lithium-Ion Battery Cathodes via One-Pot Synthetic Route from Precursors to Electrode Sheets

• Published in: Advanced materials interfaces Vol. 3; no. 14; p. np
• Main Authors: Lee, Jung Han, Kim, Ju-Myung, Kim, Jung-Hwan, Jang, Ye-Ri, Kim, Jeong A, Yeon, Sun-Hwa, Lee, Sang-Young
• Format: Journal Article
• Language: English
• Published: 01.07.2016
• Subjects: Accessibility; Architecture; Carbon; Cathodes; Electrodes; Gravimetry; Lithium-ion batteries; Multi wall carbon nanotubes; Vanadium pentoxide
• ISSN: 2196-7350; 2196-7350
• DOI: 10.1002/admi.201600173

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 sub(2)O sub(5)) that relies on multielectron insertion/extraction reactions. Application of V sub(2)O sub(5) to LIB cathodes, however, has been mostly focused on V sub(2)O sub(5) materials themselves with little emphasis on V sub(2)O sub(5)-incorporated cathode sheets. Here, as an unusual electrode-architecture approach to achieve ultrahigh-capacity V sub(2)O sub(5) cathode sheets, a new class of self-standing V sub(2)O sub(5) cathode sheets is demonstrated based on V sub(2)O sub(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 sub(2)O sub(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 sub(2)O sub(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. The self-standing (V sub(2)O sub(5)/multiwalled carbon tubes)/polyacrylonitrile nanofibers-mediated cathode sheet is presented as a new concept of electrode architecture to address the long-standing challenges of V sub(2)O sub(5) cathode sheets. The one-pot synthesis of the V sub(2)O sub(5) cathode sheet via concurrent electrospraying/electrospinning process followed by calcination enables unprecedented improvements in the gravimetric/volumetric cathode capacity, rate capability, and cycling performance far beyond those accessible with conventional electrode technologies.