Ionic liquid–based solid electrolytes (ionogels) for application in rechargeable lithium battery

Ionic liquid (IL) based solid electrolytes are commonly known as ionogels (IGs). IGs are synthesized by the incorporation/entrapment of ILs in any inorganic- or/and organic-type solid host materials. After the incorporation of any typical lithium salt in IGs, it offers several advantages for lithium-ion rechargeable batteries (LIBs), including safety-based processing compatibility under the various operating thermal and electrochemical conditions. IGs show various advantages in terms of ionic conductivity, thermal and mechanical stability, chemical and electrochemical stability compared with the conventional liquid–based electrolytes, and other solid electrolytes. These exotic features show that IGs are not only considered for LIBs but also used as promising solid electrolytes for the development of next-generation rechargeable battery technologies. Various approaches for developing the lithium-ion conducting IGs and their effect as solid electrolytes on the performance of LIBs are reviewed here. Moreover, this article emphasizes smart approaches for the synthesis of organic, inorganic, and hybrid host-based IGs to achieve LIBs with high capacity, high rate capability, and excellent cycling stability. It is believed that the article will provide an update for the reader regarding the key advancement in the field of IL-based solid electrolytes (IGs) for application in the rechargeable lithium battery.