Long-Cycling Cellulose-Based Gel Polymer Electrolyte Utilizing Nanohydrotalcite as a Li+ Transport Redistributor.

The hydroxyl groups on the surface of the cellulose-based gel polymer electrolyte lead to poor interfacial compatibility due to side reactions with lithium sheets. In this paper, a novel cellulose-based gel polymer electrolyte was prepared by uniformly coating the surface of a cellulose membrane with a nanohydrotalcite/PVDF-HFP composite using electrospinning technology. This cellulose-based gel polymer electrolyte exhibits good interfacial compatibility and excellent cycling stability (91.7% specific capacity retention after 500 cycles at 0.5C). Theory and experiments have shown that nanohydrotalcite on the surface of cellulose membrane can effectively prevent the contact of hydroxyl groups with lithium sheets to reduce the side reactions. In addition, nanohydrotalcite can also act as a Li+ transport redistributor to facilitate the uniform deposition of Li+ and reduce the formation of lithium dendrites to extend the cycle life.

Electrospun Sandwich-like Structure of PVDF-HFP/Cellulose/PVDF-HFP Membrane for Lithium-Ion Batteries.

Cellulose membranes have eco-friendly, renewable, and cost-effective features, but they lack satisfactory cycle stability as a sustainable separator for batteries. In this study, a two-step method was employed to prepare a sandwich-like composite membrane of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)/cellulose/ PVDF-HFP (PCP). The method involved first dissolving and regenerating a cellulose membrane and then electrospinning PVDF-HFP on its surface. The resulting PCP composite membrane exhibits excellent properties such as high porosity (60.71%), good tensile strength (4.8 MPa), and thermal stability up to 160 °C. It also has exceptional electrolyte uptake properties (710.81 wt.%), low interfacial resistance (241.39 Ω), and high ionic conductivity (0.73 mS/cm) compared to commercial polypropylene (PP) separators (1121.4 Ω and 0.26 mS/cm). Additionally, the rate capability (163.2 mAh/g) and cycling performance (98.11% after 100 cycles at 0.5 C) of the PCP composite membrane are superior to those of PP separators. These results demonstrate that the PCP composite membrane has potential as a promising separator for high-powered, secure lithium-ion batteries.