A novel electrochemically compatible, high‐voltage, and nonflammable electrolyte has been prepared based on a fluorinated ether with no flash point, that is, 1,1,1,3,3,3‐hexafluoroisopropyl methyl ether (HFPM). Our experimental results demonstrate that this F‐electrolyte is not only totally nonflammable in fire burning tests, but it also exhibits a remarkably high anodic stability of at least 5.5 V (vs. Li+/Li). In particular, this F‐electrolyte has good compatibility with graphite anodes. Mesocarbon microbeads/LiNi0.5Mn1.5O4 18650 batteries made with this F‐electrolyte display an excellent cycling stability with 82 % capacity retention after 200 cycles at a high cutoff voltage of 4.9 V, confirming their potential as high‐voltage lithium‐ion batteries with enhanced safety and longevity.
Electrolytes play a decisive role in determining the energy density, cycling life, safety, and temperature adaptability of lithium-ion batteries or any advanced battery chemistries. Here a "pseudoconcentrated electrolyte" combining advantages of both concentrated and diluted electrolytes is described as a brandnew approach for high-performance lithium-ion batteries. By designing a heterogeneous liquid structure for an electrolyte, we made it possible for Li + to form a solvation sheath structure that is only attainable in concentrated electrolytes while using a low salt concentration. Such a pseudoconcentrated electrolyte, with lithium bis(trifluoromethanesulfonyl imide) as lithium salt and carbonates as solvents, demonstrates high electrochemical oxidation resistance and a high anticorrosion capability toward an Al current collector, which are usually the characteristics of concentrated electrolytes, as well as high ionic conductivity and low viscosity, which are only available from diluted electrolytes. Thus, this innovative approach provides a brand-new avenue to tailor electrolyte properties for advanced battery chemistry applications.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.