Mg–Al hydroxide intercalated ionic liquids for quasi-solid-state lithium batteries

Solid -state lithium batteries are considered safer energy storage, but their payload and energy density are limited due to the large interfacial impedance caused by the poor Li+ transmission power between the solid-state electrolyte (SSE) and the electrode material. To involve the interface problem, we studied a solid-state electrolyte based on Mg–Al layered double hydroxides (LDH) intercalated ionic liquids containing lithium salt (LiIL). The characterization of LDHs and LDH-LiIL was considered by X-ray diffraction. Morphology was examined in the scanning electron microscope. This electrolyte exhibits good electrochemical performance with an ionic conductivity of the order of 10−3 at room temperature. Half-cell Li/LiFePO4 with LDH-LiIL electrolytes has a capacity above 110 mAh·g−1 at 1 C. In addition to the inherently high ionic conductivity of LDH-LiIL, the interfacial wetting effect of LiIL results in a unique interfacial contact between the electrolyte and the electrode, creating an effective Li+ conductive network throughout the cell, considered a key factor in the superior performance of solid-state lithium battery.