A novel cellulose membrane from cattail fibers as separator for Li-ion batteries

Cattail is widely abounding in wetlands and marshes and is usually considered as an abundant and inexpensive biomass lignocellulose resource due to its rapid growth. In this paper, a novel cellulose (named as TOCF) separator for Li-ion batteries (LIBs) is successfully fabricated from cattail fibers by 2, 2, 6, 6-tetramethylpiperidine-1-oxyl (TEMPO) oxidation and vacuum filtration. The proposed TOCF membrane shows good tensile strength (75 MPa), superior thermal dimensional stability, sufficient porosity (64.8%), outstanding liquid electrolyte uptake (323%) as well as large ionic conductivity (2.83 mS cm−1). Moreover, the Li/LiFePO4 cell assembled using the TOCF separator demonstrates better discharge capacity and cycling stability than the cell with a commercial Celgard separator. Thus, the TOCF separator is a promising and low-cost candidate used in high-performance LIBs.