Nano SiO2 particle formation and deposition on polypropylene separators for lithium-ion batteries

Abstract

This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. b s t r a c tThe novelty of this work is the formation and deposition of SiO 2 , as opposed to deposition using commercially available SiO 2 powder suspension in the solution, to form ceramic coating on polypropylene (PP) separators for lithium-ion battery. The formation of SiO 2 nanoparticles with uniform particle size is accomplished through direct hydrolysis of tetraethyl orthosilicate (TEOS), while the deposition of the formed SiO 2 on PP separators was conducted in the same solution containing polyvinylidene fluoridehexafluoropropylene (PVDF-HFP) as binders and acetone as the solvent. The effects of the ceramic coating on the surface morphology, tensile strength, contact angles, electrolyte uptake, thermal shrinkage of the PP separators and the cell performances such as battery rate capability and Coulombic efficiency were investigated. The coated separators show significant reduction in thermal shrinkage and improvement in tensile strength, contact angles, electrolyte uptake and battery performance as compared to the plain PP separator. Crown

Characterising the structural properties of polymer separators for lithium-ion batteries in 3D using phase contrast X-ray microscopy

“…The PE layer exhibits the greatest resistance per unit thickness compared to its counterparts in the Celgard samples, which were manufactured using a dry process. The ceramic layers are shown to have little effect on the overall tortuosity of the membrane, but have been shown to improve the thermal and mechanical properties [52,53], as well as the wettability of polymer separators [54,55]. Hence, the combination of high tensile strength resulting from its isotropic structure, high tortuosity, and the presence of the ceramic layer [52,53] would help mitigate the risks associated overheating, dendrite growth and electrode displacement [56,57], making this separator favourable for safety critical applications.…”

Flexible inorganic membranes used as a high thermal safety separator for the lithium-ion battery

“…However, a safety issue, caused by the thermal shrinkage of the polyolens at higher temperatures, has limited their further applications in energy storage systems, especially in hybrid electric vehicle (HEV) areas. 8,9 To improve the thermal stability of the separator for the safety of lithium-ion batteries, the polyolen membranes were modied [10][11][12][13] and lots of new type of separators [14][15][16][17][18] were designed. Among them, the purely inorganic separators prepared with the sintering method could have the advantage of "absolutely" thermal stability, strong electrolyte absorption content and no dendrite puncturing problems.…”

Deformable and flexible electrospun nanofiber-supported cross-linked gel polymer electrolyte membranes for high safety lithium-ion batteries

“…However, the practical application of the thin gel polymer electrolyte lm with low ionic resistance is currently limited to a large extent due to its poor mechanical strength and low stability. [6][7][8] Electrospun nanobrous membranes are a particular type of polymer lms with a large specic surface area, high porosity, and an interconnected network structure. This special structure endows the polymer with excellent properties, such as good liquid absorbency, and contributes to the formation of a membrane with smooth ion conduction channels and high ionic conductivity.…”