Cathode-electrolyte interphase (CEI) is vital to the safety and lifespan of high-voltage cathode materials. However, the CEI formation mechanism in Li-ion batteries remains unclear. In a recent Matter article, Zhang et al. report on a real-time formation mechanism. Here, we discuss challenges and propose design principles in the fabrication of high performance CEI. Cathode-electrolyte interphase (CEI) is vital to the safety and lifespan of high-voltage cathode materials. However, the CEI formation mechanism in Li-ion batteries remains unclear. In a recent Matter article, Zhang et al. report on a real-time formation mechanism. Here, we discuss challenges and propose design principles in the fabrication of high performance CEI. In situ TEM visualization of LiF nanosheet formation on the cathode-electrolyte interphase (CEI) in liquid-electrolyte lithium-ion batteriesZhang et al.MatterFebruary 7, 2022In BriefThe formation behaviors of LiF nanocrystals have been studied on anodes in Li-ion batteries; there is no research work reporting LiF crystal growth on cathodes. Here, we report a real-time LiF crystal formation on positively charged titanium (Ti) electrodes in an electrochemical liquid cell with 150-nm-thick Li hexafluorophosphate (LiPF6)/propylene carbonate (PC) liquid electrolyte loaded. The LiF nanocrystals show two-dimensional (2D) morphologies on the electrode surface, which can serve as a cathode electrolyte interface (CEI). Full-Text PDF