Delamination-free cathode/separator/anode assembly by introduction of multi-layer coated separator for long-term stable performance of lithium-ion batteries

Abstract

A lithium-ion batteries (LIBs) has become the alternative energy supply for portable devices and high-power applications such as electric vehicle and energy storage system for renewable energy. Next-generation LIBs should demonstrate high stability and safety for long-term and high energy density operation. It calls for the advancement of battery components such as the electrode, separator, and electrolyte. Among them, separators with high reliability and security are in urgent demand for the superior performance of LIBs. A new-type separator of LIBs with superior mechanical property has been designed and fabricated herein via ceramic and adhesive coating layer on both sides of a polyethylene separator. Additionally, we introduced the lamination process, which triggers the expression of the adhesive strength between the electrode and the separator without the suppression of lithium ion movement through the porous structure of coating layer at the separator. These multi-layer coated separators (MCSs) present excellent electrochemical performance build up with cycling, when used in coin and pouch cells. This implies that the novel separator is promising for longer stable applications. Also, two-coating layers were fabricated by an aqueous coating process. Utilization of an aqueous process not only offers environmental benefits but is also effective in cost reduction.