Sustainable cathode-electrolyte interphases of nickel-rich layered oxides in-situ functionalized by lithium fluoride abundant layers for lithium-ion batteries

Although Nickel-rich cathodes have been noted as key materials for electric vehicles, their reliable hightemperature performance is considered the primary bottleneck for future applications. Herein, we propose 1H, 1H, 5H-octafluoropentyl 1,1,2,2-tetrafluoroethyl ether as an interface stabilizing additive for Ni-rich cathode, which can offer cathode-electrolyte interphase layers. It is anticipated that fluorine-abundant proposed additives can form lithium fluoride-based cathode-electrolyte interphase layers through electrochemical oxidation, making the cathode-electrolyte interphase layers robust and durable due to their improved mechanical properties. In the analyses, it is observed that the suggested additive provides 5.5 nm-based cathode-electrolyte interphase layers at the cathode interface by electrochemical oxidation. In terms of cycling performance, the additive-contained electrolytes reveal prolonged cycling retention (62.2%), whereas the standard electrolyte displays only 40.7% retention because electrolyte decomposition is not managed in the absence of the additive. Further, post-analyses indicate that durable lithium fluoride-based cathode-electrolyte interphase layers remain on the recovered cathode, whereas most of the surface is covered by decomposed adducts in the cycled cathode in the presence of the standard electrolyte.