Ceramic-Coated Separator to Enhance Cycling Performance of Lithium-ion Batteries at High Current Density

Abstract

Given the global demand for green energy, the battery industry is positioned to be an important future technology. Lithium-ion batteries (LIBs), which are the most widely used battery in the market, are the focus of various research and development efforts, from materials to systems, that seek to improve their performance. The separator is one of the core materials in LIBs and is a significant factor in the lifespan of high-performance batteries. To improve the performance of present LIBs, electrochemical testing and related surface analyses of the separator is essential. In this paper, we prepared a ceramic (Boehmite, γ-AlOOH) coated polypropylene separator and a porous polyimide separator to compare their electrochemical properties with a commercialized polypropylene (PP) separator. The prepared separators were assembled into nickelmanganese-cobalt (NMC) cathode half-cell and full-cell lithium-ion batteries. Their cycling performances were evaluated using differential capacity and electrochemical impedance spectroscopy with ethylene carbonate:dimethylcarbonate (EC:DMC) electrolyte. The ceramic coated polypropylene separator exhibited the best cycle performance at a high 5 C rate, with high ionic conductivity and less resistive solid electrolyte interphase. Also, it was confirmed that a separator solid electrolyte interface (SSEI) layer formed on the separator with cycle repetition, and it was also confirmed that this phenomenon determined the cycle life of the battery depending on the electrolyte.

Dual‐Modified Electrospun Fiber Membrane as Separator with Excellent Safety Performance and High Operating Temperature for Lithium‐Ion Batteries

“…[18] In the past decade, three main strategies have been used for designing and preparing separators for LIBs, and many new separators beyond polyolefin or modified polyolefin-based separators have been designed and prepared. The first strategy is to prepare new separators beyond polyolefin or modified polyolefinbased separators by coating inorganic particles on the surface of polyolefin-based organic components, such as polyacrylonitrile separator with increased porosity and enhanced electrolyte wettability is fabricated by electrospinning method, [19] and Al 2 O 3 modified polyolefin membrane with enhanced electrolyte wettability and thermal stability can be obtained. [20] The second strategy is to develop full-inorganic composition separators to improve the thermal stability of the assembled devices.…”

Thermal Stability Enhancement of Separators by Ceramic/Carboxymethyl Cellulose Nanofiber Coating

“…As a promising strategy, Al 2 O 3 ceramic coatings provide good heat dissipation, which increases the operating temperature range and enhances the mechanical strength of the separator. Moreover, the high surface area and good wetting properties of the Al 2 O 3 ceramic nanoparticles can contribute to the e cient electrolyte in ltration and retention, making the battery separator more e cient and reliable (Yu et al 2016;Cho et al 2021;Zhou 2022).…”