To improve the energy density of lithium (Li) batteries and solve the problems of conventional single-salt electrolytes such as poor thermal stability

low conductivity

and Li dendrites

developing new blended-salts electrolytes has become an important research direction of Li battery electrolytes. Blended-salts can change the ion conductivity

Li ion solubility

viscosity

and other properties of the solution

and can improve the electrochemical performance of the battery by affecting the interface of electrode and electrolyte as well as the surface and interface of electrode materials. This paper collects the latest research literature at home and abroad

and reviews the research progress of blended-salts electrolytes for Li batteries

including different research directions such as Li ion batteries

Li metal batteries

Li sulfur batteries

and solid state batteries. The advantages and disadvantages of commonly used single-salts are summarized

the effects and mechanism explanations of hybrid electrolytes on different surface interfaces of batteries are elaborated

and the applications of blended-salts in different battery systems are analyzed. At last

the existing problems of blended-salts electrolytes and interface reactions are discussed

and the development direction and application of characterization of novel blended-salts and interface reactions are given. The current research studies of blended-salts are mostly limited to performance improvement and its mechanism needs to be further investigated. The existing explanation usually unfolds from single-salts

and the mechanism of synergistic effect of blended-salts is an important research direction in the future.