Utilization and Advancement of an Electrolyte Containing Mixed Electrolyte Salts in Electrochemical Energy Storage Devices Mainly Based on Lithium-Ion Batteries

An electrolyte salt as an indispensable component has a dramatic impact on the performance of electrochemical energy storage devices. However, every electrolyte salt cannot satisfy all the needs of an electrolyte for rechargeable batteries. For example, in lithium-ion batteries, shortages like the decomposition of the lithium hexafluorophosphate (LiPF₆)-based electrolyte at high temperature, the corrosion to the Al cathodic current collector of the lithium difluorosulfonamide (LiFSI)- or lithium bistrifluoromethanesulfonylimide (LiTFSI)-based electrolyte, the low conductivity of the lithium tetrafluoroborate (LiBF₄)-based electrolyte, and the inappropriately stable electrochemical windows of the lithium difluorooxalateborate (LiDFOB)- or lithium bisoxalatoborate (LiBOB)-based electrolyte restrict further development of the single lithium salt-based electrolyte for the rechargeable batteries. In this case, much effort has been spent in overcoming the inherent shortage of each electrolyte salt, in which the strategy of mixing an electrolyte salt is attracting growing attention. Herein, an overview about the research progress surrounding the mixed electrolyte salts is presented, including the effect of mixed electrolyte salts on the property’s optimization of the electrolyte, the performance of the Al current collector, various cathodes, next-generation anodes, and full batteries. This review aims to elucidate the role of a mixed electrolyte salt in how it influences the battery’s components, ultimately changing the performance of various rechargeable batteries.