Single-Phase Ternary Compounds with a Disordered Lattice and Liquid Metal Phase for High-Performance Li-Ion Battery Anodes

Si is considered as the promising anode materials for lithium-ion batteries (LIBs) owing to their high capacities of 4200 mAh g(−1) and natural abundancy. However, severe electrode pulverization and poor electronic and Li-ionic conductivities hinder their practical applications. To resolve the afore-mentioned problems, we first demonstrate a cation-mixed disordered lattice and unique Li storage mechanism of single-phase ternary GaSiP(2) compound, where the liquid metallic Ga and highly reactive P are incorporated into Si through a ball milling method. As confirmed by experimental and theoretical analyses, the introduced Ga and P enables to achieve the stronger resistance against volume variation and metallic conductivity, respectively, while the cation-mixed lattice provides the faster Li-ionic diffusion capability than those of the parent GaP and Si phases. The resulting GaSiP(2) electrodes delivered the high specific capacity of 1615 mAh g(−1) and high initial Coulombic efficiency of 91%, while the graphite-modified GaSiP(2) (GaSiP(2)@C) achieved 83% of capacity retention after 900 cycles and high-rate capacity of 800 at 10,000 mA g(−1). Furthermore, the LiNi(0.8)Co(0.1)Mn(0.1)O(2)//GaSiP(2)@C full cells achieved the high specific capacity of 1049 mAh g(−1) after 100 cycles, paving a way for the rational design of high-performance LIB anode materials. [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40820-023-01026-4.