Lithium ion batteries (LIBs), which have the highest energy density among all currently available rechargeable batteries, have recently been considered for use in hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and pure electric vehicles (PEV). A major challenge in this effort is to increase the energy density of LIBs to satisfy the industrial needs of HEVs, PHEVs, and PEVs. Recently, new types of lithium-air and lithium-copper batteries that employ hybrid electrolytes have attracted significant attention; these batteries are expected to succeed lithium ion batteries as next-generation power sources. Herein, we review the concept of hybrid electrolytes, as well as their advantages and disadvantages. In addition, we examine new battery types that use hybrid electrolytes.