In Situ-Formed Electrolyte Design: Comprehensive Study of the Charge–Discharge Mechanism for the Improvement of the Performance of Conversion-Type Anode

MgH2 has been extensively examined for its potential as a lithium-ion battery anode owing to its high theoretical capacity and appropriate redox potential (0.5 V). To increase energy density, MgH2 was utilized to create a solid electrolyte in situ, thereby increasing the active material content in the anode layer. For MgH2, exploration of increased electrode thickness was undertaken to enhance energy density, with thicknesses surpassing 140 µm demonstrating consistent capacity. Ex situ analysis revealed disparities in reaction distribution based on electrode thickness. Additionally, investigations into MgCl2 and Ca(BH4)2 for in situ electrolyte formation displayed potential but necessitated further optimization. TiH2 is promising anode material with its high capacity and low potential. The mixing of TiH2 with MgH2 enhanced electronic conductivity and dynamic performance. Variations in carbon additives exerted significant effects on capacity and energy density. The efficiency of delithiation/lithiation was found to correlate with the conductivity of lithium salt. Subsequent research should focus on elucidating the impacts of product morphology and mechanical properties.