Sandwiched polyimide‐composite separator for lithium‐ion batteries via electrospinning and electrospraying

Abstract

A novel type of sandwiched separator for lithium-ion batteries has been developed by combining electrospinning and electrospraying techniques. This separator consists of three layers in which the top and bottom layers are prepared by electrospinning a poly(amic acid) ammonium salt (PAAS) solution and the middle layer is obtained by electrospraying a mixture of the PAAS solution and inorganic nanoparticles (SiO 2 or Al 2 O 3). Subsequently, the sandwiched separators are imidized at 250 C in a nitrogen atmosphere. The morphology, porosity, thermal stability, mechanical strength, wettability and electrochemical performance of sandwiched separators were examined and the results were compared with those of a commercial separator (SV718). The thermal properties of the sandwiched separators and SV718 were determined using a thermal gravimetric analyzer and a differential scanning calorimeter. The sandwiched separators had no melting peak, whereas SV718 had a melting peak at 139 C, demonstrating the higher thermal stability of sandwiched separators. The electrolyte contact angles of sandwiched separators were around 11.5 , which were significantly lower than that of SV718. Moreover, the porosity and electrolyte uptake of sandwiched separators were over 81% and 910%, respectively, while those values of SV718 were 43% and 121%, respectively. The higher porosity, electrolyte uptake, and wettability of the sandwiched separators resulted in the better their cycling performance and higher specific-discharge capabilities than SV718.

Advances in Electrospun Hybrid Nanofibers for Biomedical Applications

“…They had achieved this by the fabrication of hybrid nanofibers with inorganic nanoparticles sandwiched between two layers. Here, immobilization of nanoparticles on the surface of a nanofiber was performed by electrospraying [ 152 ]. Additionally, hybrid nanofibers contained a layer of SiO 2 and Al 2 O 3 .…”

“…Interestingly, we have observed that 3D PCL microfibers prepared by centrifugal spinning showed a better proliferation of fibroblasts while 2D core/shell nanofibers prepared by needleless emulsion electrospinning showed a higher proliferation of keratinocytes [ 169 ]. Polycaprolactone/gelatin/hyaluronic acid nanofibers were developed to mimic a glioblastoma tumor extracellular matrix [ 152 ]. In another study, electrospun PCL membranes blended with hydroxyapatite (HA) were developed, and its potential in differentiating inflamed dental pulp stem/progenitor cells (IDPSCs) into odontoblasts was evaluated [ 180 ].…”

Recent Advances on Materials for Lithium-Ion Batteries

“…The future trends on the separator technology include the development of more complex and multifunctional membranes, particularly with the increasing of the devices' safety, by adding shutdown functions to the separators [199]. Novel separator architectures based on three layers were developed combining electrospinning and electrospraying techniques and composed of PI and poly(amic acid) ammonium salt (PAAS) solution with inorganic nanoparticles (SiO 2 or Al 2 O 3 ) [185]. Another three-layer separator was produced based on poly (ethylene-co-vinyl acetate) (EVA)/polyimide (PI)/EVA (PIE) with high thermal stability and a shutdown function [230].…”

High‐performance flexible temperature sensor from hybrid nanocomposite for continuous human body temperature monitoring

“…[11][12][13] Electrospinning is another technique that seems appropriate for developing flexible devices although it has not been explored deeply with respect to the fabrication of temperature sensors. [14] It is simple, productive and compared to solvent cast films, electrospun films show higher malleability due to a very high aspect ratio. [10,15] Wang et al prepared an Ag-SBS-based bi-modal electrospun flexible temperature-pressure sensor with linear temperature sensitivity and stable temperature observations under various pressure loadings.…”