Spatially anchoring the lithiophilic composites within the mixed-conducting phase: A hybrid storage mechanism enabled by the Al-Si@AlSiO_X composite

The soaring demand for high-energy–density lithium batteries necessitates the technological innovation of anodes with high gravimetric capacity, cycling durability, and the comparable production cost as the graphite anodes. Here we report an aluminothermic method to develop the multifunctional Al-Si@AlSiO_X composite for various types of battery configurations. Without additional post-treatment after the aluminothermic process, the multi-components in the composite enable the robust cyclability and high Coulombic efficiency in the full-cell prototype. Additionally, we quantitatively analyze the capacity contribution ratio from the lithium alloying and metallic plating processes in the hybrid metallic batteries; the dynamic phasic evolution analysis further confirms the mixed-conducting properties of the interconnected Li-Al alloy/LiAlSiO_X network to boost the electrode kinetics. These features render the Al-Si@AlSiO_X composite anode the potential use in the energy-dense metallic batteries with the average CE of higher than 99.5% (0.25 mA cm⁻², 1 mAh cm⁻²) and the stabilized lithium deposition amount up to 10 mAh cm⁻².