Carbon‐Coated Electrospun V₂O₅ Nanofibers as Photoresponsive Cathode for Lithium‐Ion Batteries

Abstract

Photo‐rechargeable batteries represent a synergistic concept that integrates both energy harvesting and energy storage modalities based on dual‐functional materials. Electrospun vanadium oxide nanofibers (VNFs) seamlessly coated with conductive carbon (VNF‐C‐120) as dual‐action cathode materials for photo‐rechargeable lithium‐ion batteries (LIBs) are reported. The materials deliver a high discharge capacity of 160 mAh g−1, which could be increased up to 184 mAh g−1 (C rate of 0.75) under light illumination that confirmed the photoresponsive behavior. Long‐term stability tests (300 cycles at 0.75C) and the post‐mortem analysis show that besides being a conductive sheath, the carbon coating is also essential in retaining the structural and morphological stability of V2O5 fibers, which was manifested in a higher capacity retention upon cycling compared to the non‐carbon‐coated VNF (43.85% capacity retention VNF and 61.13% capacity retention for VNF‐C‐120 after 300 cycles). In contrast, the pristine VNF electrode cannot reach 400 cycles, due to the failure of the cell, which, however, is prevented in cells operating with carbon‐coated electrodes. Further, the photo‐rechargeability of the cell is demonstrated under a UV lamp that delivered an overall conversion efficiency of 4.24% for VNF and 5.07% for the VNF‐C‐120.

A perspective on photoelectrochemical storage materials for coupled solar batteries

“…An effective strategy for harnessing solar energy is to combine photoelectric conversion materials with energy storage materials. 59 To achieve this, the substrate material (or current collector) is also crucial for efficient charge separation and transfer. The layer-by-layer assembly design of multi-component photoelectrochemical storage materials, as shown in Fig.…”

Advances in Electrospun Materials and Methods for Li-Ion Batteries

“…In addition to producing electrodes for electrochemical batteries, electrospinning is also used to construct the cathode for photo-responsive batteries, and the working is given in Figure 4 c. Vanadium oxide nanofibers coated with conductive carbon, such as the VNF-C-120 [ 54 ], are used as the cathode for lithium-ion batteries that can be recharged using sunlight. Given its photo responsiveness, reversible redox active behavior, necessary bandgap, and affordability, V 2 O 5 is selected as the ideal cathode.…”

“…[ 23 ] 2020, Elsevier) ( c ) Schematic representing the photo charging mechanism of (I) VNF and (II) VNF-C-120 (reused with copyrights from Ref. [ 54 ] 2022, Wiley) ( d ) Cycling stability and capacity retention tests at 0.75 C of VNF (red) and VNF-C-120 (gray) (reused with copyrights from Ref. [ 54 ] 2022, Wiley).…”

“…[ 54 ] 2022, Wiley) ( d ) Cycling stability and capacity retention tests at 0.75 C of VNF (red) and VNF-C-120 (gray) (reused with copyrights from Ref. [ 54 ] 2022, Wiley).…”

Recent progress in device designs and dual‐functional photoactive materials for direct solar to electrochemical energy storage

“…Constructing an electron transfer layer or a hole blocking layer in the photoelectrode is a valid method to reduce the recombination of photogenerated carriers. Mathur et al [ 167 ] designed electrospun vanadium oxide nanofibers coated with conductive carbon (VNF‐C), in which the conductive carbon is the electron transfer layer and the in situ formation of VO 2 on the surface of VNF‐C is the hole‐blocking layer. These two layers in the VNF‐C produce a space charge layer, which enables rapid transport of photogenerated electrons and leaves behind photogenerated holes to participate in the following oxidation reaction (Figure 14a).…”