Lithium Vanadium Phosphate/Carbon Nanofiber Films as Selfstanding, Binderfree, and Flexible Cathodes for Lithium‐Ion Batteries

Abstract

Flexible lithium vanadium phosphate/carbon nanofiber (i.e., Li3V2(PO4)3/C) were fabricated by an electrospinning process combined with hot‐pressed sintering, and are used in lithium‐ion batteries as selfstanding, binderfree and flexible cathodes. The microstructure and crystalline phase of the as‐prepared films are characterized by scanning electron microscopy, transmission electron microscopy, and X‐ray diffractometry. The electrochemical properties of the Li3V2(PO4)3/C nanofiber films were analyzed by cyclic voltammetry and galvanostatic charge/discharge tests. When the nanofiber precursor was sintered at 850 °C for 20 h, the resulting film displays high flexibility and crystallinity. This selfstanding Li3V2(PO4)3/C film exhibits a superior rate performance even at 20 C and good cycle ability, with a retention capacity of 112 mAh g−1 at a current density of 1 C after 1000 cycles and 71 mAh g−1 at 5 C after 800 cycles. These features are attributed to the special composite structure formed by the Li3V2(PO4)3 and the carbon support, and the 3D long‐range conductive networks.

Approaching high performancePVDF‐HFPbased solid composite electrolytes withLLTOnanorods for solid‐state lithium‐ion batteries

“…The cycling properties and rate capabilities of the solid‐state lithium‐ion batteries directly affect its commercial application 43 . To corroborate the superiority of the SCE, the NCM622/SCE/Li solid‐state batteries were assembled and tested at room temperature.…”

“…The cycling properties and rate capabilities of the solidstate lithium-ion batteries directly affect its commercial application. 43 To corroborate the superiority of the SCE, the NCM622/SCE/Li solid-state batteries were assembled and tested at room temperature. Figure 7A displays the rate capabilities of the batteries assembled with various PVDF-HFP-based SCEs with different contents of LLTO nanorods.…”

Nanostructured Li3V2(PO4)3 Cathodes

“…F) SEM image of Li 3 V 2 (PO 4 ) 3 /C nanofiber film (inset: bending of the Li 3 V 2 (PO 4 ) 3 /C nanofiber film). G) Rate performance of Li 3 V 2 (PO 4 ) 3 /C nanofiber film in the potential range of ≈3.0–4.8 V. Reproduced with permission . Copyright 2016, Wiley‐VCH.…”

“…The Li 3 V 2 (PO 4 ) 3 /C composite fiber membrane electrode exhibited excellent rate and cycle performances, e.g., delivering a discharge capacity of 143.4 mA h g −1 after 850 cycles (capacity retention: 98%, Figure E), which could be ascribed to the obtained long‐range conductive networks to greatly improve the electron transfer rate. Similarly, Pi et al adopted a facile electrospinning process and hot‐pressed sintering treatment to fabricate flexible and binder‐free Li 3 V 2 (PO 4 ) 3 /C nanofiber film cathodes. The composite film consisted of fibers of 173–322 nm in diameter and continuous conduvtive networks (Figure F).…”