The role of lignin-molybdenum disulfide as a nano-filler in enhancing the performance of crosslinked hydrogel nanofibers membrane for lithium-ion battery separators

The anticipated development of modern lithium-ion batteries (LIBs) has significantly slowed down due to safety concerns, and the fabrication of sophisticated separators is considered a necessary approach to enhance the safety of LIBs. Recently, the use of crosslinked hydrogel nanofiber membranes as LIBs has demonstrated encouraging outcomes. Nevertheless, their mechanical properties still require enhancement. This study introduces a simple method for preparing hybrid composite crosslinked hydrogel nanofiber membranes of acrylamide (AM) and polyvinyl alcohol (PVA) reinforced with nanofiller of molybdenum disulphide nanosheets loaded on lignin (MoS 2 @L). Initially, MoS 2 @L nanofiller was prepared by using lignin as a substrate to enhance MoS 2 dispersion and also to improve its compatibility with the nanofibers matrix. Subsequently, an electrospinning-polymerization technique was used to prepare a crosslinked hydrogel nanofiber membrane of PVA and AM with different amounts of MoS 2 @L. The optimal ratio of electrospinning solution with nanofiller (MoS 2 @L) content were determined. The incorporation of MoS 2 @L revealed that the PVAM-MoS 2 @L composite hydrogel nanofiber separator had the maximum tensile strength (16.5 MPa). The PVAM-MoS 2 @L separator demonstrated high electrolyte absorption capacity (687.4 %), high porosity (85.3 %), high ion conductivity (3.13 mS/cm), and a high lithium-ion transfer number (tLi+ = 0.563). Notably, the PVAM-MoS 2 @L separator enabled coin cells to exhibit commendable electrochemical performance. Compared to the PVA and Celgard separators, the PVAM-MoS 2 @L separator maintained a higher capacity retention of 82.7 % (117.3 mAh/g) even after 500 cycles at 1C. These results underscore the potential of the PVAM-MoS 2 @L separator as a high-performance, safe, and commercially viable alternative for next-generation LIBs.