LiBH4 as a Solid-State Electrolyte for Li and Li-Ion Batteries: A Review

In this paper, the methods used to enhance the conductivity of LiBH4, a potential electrolyte for the construction of solid-state batteries, are summarized. Since this electrolyte becomes conductive at temperatures above 380 K due to a phase change, numerous studies have been conducted to lower the temperature at which the hydride becomes conductive. An increase in conductivity at lower temperatures has generally been obtained by adding a second component that can increase the mobility of the lithium ion. In some cases, conductivities at room temperature, such as those exhibited by the liquid electrolytes used in current lithium-ion batteries, have been achieved. With these modified electrolytes, both lithium metal and lithium-ion cells have also been constructed, the performances of which are reported in the paper. In some cases, cells characterized by a high capacity and rate capability have been developed. Although it is still necessary to confirm the stability of the devices, especially in terms of cyclability, LiBH4-based doped electrolytes could be employed to produce solid-state lithium or lithium-ion batteries susceptible to industrial development.