Syringeless electrospinning of PVDF/SiO2 as separator membrane for high-performance lithium-ion batteries

Lithium-ion batteries (LIBs) have attained great attention nowadays as a next-generation energy solution, but all of the current components need to be improved in order to meet the requirement for LIBs with mid-/high power density and capacity. Especially, the stretched olefin membrane as a separator should be reconsidered because it contains intrinsic limitations in pore size and electrolyte wettability, which is directly related to fast charge/discharge rate of LIBs. Electrospun non-woven nanofiber web has been considered as a promising candidate to improve Li-ion transportation. However, several features should be addressed for practical applications, such as the production rate (and cost) of the electrospun non-woven web, mechanical properties, and corresponding safety. In this paper, we present the electrospun non-woven web composed of PVDF based composite nanofiber as a separator in LIBs using syringeless electrospinning. Syringeless electrospinning can increase their production rate over at least 8 times higher than conventional electrospinning. In addition, this method is advantageous to incorporate colloidal inorganic fillers into the non-woven web, which makes it possible to increase the mechanical strength and electrolyte wettability. The LIBs with our non-woven separator shows improved electrochemical performances over that with the olefin separator.