Surface functionalization of cellulose derived from hemp by tetraethyl orthosilicate (TEOS) and poly vinylidene fluoride (PVDF)-based composite separator membrane for lithium-ion batteries (LIBs)

Separators play a crucial role in enhancing the electrochemical performance of lithium-ion batteries (LIBs). However, achieving separators with exceptional electrochemical performance and high stability remains a significant challenge. In this study, we meticulously designed composite membranes based on polyvinylidene fluoride (PVDF) with varying contents of microcrystalline cellulose/tetraethyl orthosilicate (MCC/TEOS). The increase in hydrophilicity of PVDF by adding MCC-TEOS weight contents endowed the 3 wt% MCC/TEOS-based PVDF separator membrane with superior electrolyte absorption and reduced resistance, resulting in an impressive ionic conductivity of 0.514 mS/cm higher than the pristine PVDF membrane (0.253 mS/cm). Furthermore, the LIB cell utilizing the 3 wt % MCC/TEOS-based PVDF separator membrane consistently demonstrated stable charge/discharge profiles at a rate of 0.2C, achieving a specific capacity of 98 mAh/g, compared to only 43 mAh/g for the pristine PVDF membrane. These findings underscore the significant potential of MCC/TEOS as a biofiller for bio-membranes, making it an optimal choice for applications in LIBs. • Biomaterial, known as microcrystalline cellulose (MCC), was derived from hemp fiber. • The steps of biomaterial functionalization are affordable and replicable. • 3 wt% MCC/TEOS-based PVDF membrane exhibited a remarkable battery performance. • MCC/TEOS provided as the alter biomaterials for membrane applications.