Synergistic Effect of WN/Mo₂C Embedded in Bioderived Carbon Nanofibers: A Rational Design of a Shuttle Inhibitor and an Electrocatalyst for Lithium–Sulfur Batteries

Abstract

To improve the innate shuttle effect and the sluggish redox kinetics of lithium−sulfur batteries, a composite made of a bimetallic compound embedded in nitrogen-doped carbon nanofibers (CNFs) is synthesized by employing biomass collagen fibers (CFs) as a structure template. Metal anions WO 4 2− and MoO 4 2− are grafted on plant polyphenolmodified CFs and then in situ converted into WN/Mo 2 C implanted in a matrix of CNFs (WMCNFs). The obtained WN/Mo 2 C is of quantum size and uniform distribution, exposing the active sites maximally. Further, the heterostructure of the bimetallic composite enables unique electronic interaction, thereby synergistically enhancing its adsorption capability toward soluble intermediates and activating its catalytic function for liquid−liquid and liquid−solid conversions. Combining these merits, when used as a separator modification material and a sulfur host simultaneously, the WMCNFs composite exhibits remarkable cycling stability with 91.45% capacity retention after 500 cycles at 2 C and also prominent rate performance of delivering 552.75 mAh g −1 at a current rate of 10 C. Meanwhile, the stable luminescence operation of LED lights powered by the assembled pouch cell demonstrates the application potential of this biomaterial-derived composite.

Collagen‐Based Flexible Electronic Devices for Electrochemical Energy Storage and Sensing

“…To solve this, people prepared the reconstructed ESM film with uniform well-designed nanoporous structure (RESM) by dissolution and regeneration of eggshell in NaOH/Urea/LiOH solvent (Figure 4b). [132] At room temperature, LiFePO 4 /Li cells with Celgard film, ESM and RESM as separators have comparable initial discharge capacity (130,143, and 138 mAh g −1 at 0.5 C, respectively) and cycle stability (125,133, and 140 mAh g −1 at 0.5 C after 100 consecutive cycles). However, compared with Celgard-2400 and natural ESM, the negatively charged surface of RESM separators effectively suppressed the formation of lithium dendrite, even after long-term cycling at a high rate or high temperature (120 °C), also displaying boosted rate capability and cycling retention.…”

“…It is an excellent strategy to use CAs as template and carbon source to chelate metal compounds and then carbonize them to obtain carbon fiber/metal oxide as a separator modification coating material for Li‐S batteries, as shown in Figure 2. In the latest work, [ 133 ] benefiting from the unique 1D fiber structure and abundant functional groups of nitrogen‐enriched CAs, a bimetallic composite of WN/Mo 2 C modified carbon fibril bundle for separator modification of Li‐S batteries were synthesized, by grafting metal anions WO 4 2− /MoO 4 2− onto tannin‐immobilized CAs, followed by a facile one‐step calcination. While CAs realized self‐nitridation, it also contributed to the self‐template formation of carbon nanofibers.…”

Collagen and Silk Fibroin as Promising Candidates for Constructing Catalysts

“…The TOF value of the Ru-CCS catalyst for the HER was 3.70 s −1 , and the Faradaic efficiency was 96.4%. Wang used biomass collagen fibers as structural templates to synthesize bimetallic compounds embedded in N-doped carbon nanofibers (CNFs) [ 135 ]. The unique 1D fibrous structure of CNFs was conducive to the construction of high-efficiency conductive frameworks with high specific surface area, maximizing the exposure of active sites to improve electrical conductivity.…”

Renewable biomass-derived carbon-based hosts for lithium–sulfur batteries

“…Compared with single metal compound components, the implantation of different metal compounds can enhance the anchoring effect with polysulfides. 242 A bimetallic compound embedded in N-doped carbon nanofibers (WMCNFs) was synthesized and applied for LSBs by Wang et al 243 Biomass collagen fibers (CFs) utilized their native architectures to act as carbon templates while dipping two metal precursors (Fig. 15d).…”