Single-Phase Ternary Compounds with a Disordered Lattice and Liquid Metal Phase for High-Performance Li-Ion Battery Anodes
Yanhong Li, Lei Zhang, Hung‐Yu Yen, Yucun Zhou, Gun Jang, Songliu Yuan, Jeng‐Han Wang, Peixun Xiong, Meilin Liu, Ho Seok Park, Wenwu Li
Abstract
Abstract 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.