Mechanically Reinforced PVdF/PMMA/SiO₂ Composite Membrane and Its Electrochemical Properties as a Separator in Lithium‐Ion Batteries

Abstract

Compared with commercial polyolefin separators, the poor mechanical performance of electrospun polymeric membranes limits their usage as battery separators. Herein, poly(methyl methacrylate) (PMMA) and SiO2 nanoparticles were introduced into electrospun poly(vinylidene fluoride) (PVdF) membranes to form a PVdF/PMMA/SiO2 nonwoven membrane. A hot‐pressing method controlled the thickness of the electrospun membranes and improved their mechanical performance further. SEM tests show that PMMA partly melts in the composite membrane, which bonds neighboring electrospun fibers to reinforce the mechanical strength of the membrane. Uniformly distributed SiO2 nanoparticles on the electrospun fibers could supply higher resistance to mechanical impact. As a result, the composite membrane shows a high tensile strength (32.69 MPa) and high elongation at breakage (137.50 %). Differential scanning calorimetry and hot oven tests indicate that the composite membrane has excellent thermal stability. Furthermore, the addition of PMMA and SiO2 can decrease the crystallinity of PVdF and further improve the absorption of liquid electrolyte. According to the results of electrochemical tests, the composite membrane exhibits higher ionic conductivity (4.0×10−3 S cm−1) and lower interfacial resistance than those of the Celgard separator. The lithium‐ion cell assembled from the composite membrane exhibits more stable cycle performance, higher discharge capacity (158 mA h g−1), and excellent capacity retention.

Orientation of Electrospun Magnetic Nanofibers Near Conductive Areas

“…Generally, different technologies can be applied, such as the common needle-based one in which a polymer solution or melt is pressed through a needle into the electric field [4][5][6], wire-based techniques [7][8][9], cylinder-based one [10] and diverse other geometries of spinning electrode and substrate. Such nanofiber mats can be used for a broad variety of applications, such as air or water filtration [11][12][13], biotechnology and biomedicine [14][15][16][17], batteries and solar cells [18][19][20], etc.…”

Increased Mechanical Properties of Carbon Nanofiber Mats for Possible Medical Applications

“…Electrospinning allows for the creation of thin fibers in the diameter range between some ten and several hundred micrometers from diverse polymers or polymer blends [1]. Such nanofibers can be used, for example, for air filtration, [2][3][4], water filtration [5][6][7], batteries [8] or biomedical applications [9][10][11].…”

Performance improvement of electrolytic air dehumidification systems with high‐water‐uptake polymer electrolyte membranes

“…Solving the problem of PEM water content is of great significance for practical applications. The incorporation of hygroscopic inorganic nanoparticles, such as SiO 2 , TiO 2 , and ZrO 2 , into PEMs could improve their water‐retention performance . Although there have been several studies on nanocomposite membranes in recent years, most research has focused on the improvement of the proton conductivity or the selectivity of PEMs for fuel cells.…”