Designing electrode materials with engineered exposed facets provides a novel strategy to improve their electrochemical properties. However, the controllability of the exposed facet remains a daunting challenge, and a deep understanding of the correlation between exposed facet and Lit-transfer behavior has been rarely reported. In this work, single-crystal alpha-Fe2O3 hexagonal nanosheets with an exposed (001) facet are prepared with the assistance of aluminum ions through a one-step hydrothermal process, and structural characterizations reveal an Al3+-concentration-dependentgrowth mechanism for the alpha-Fe2O3 nanosheets. Furthermore, such alpha-Fe2O3 nanosheets, when used as lithium-ion battery anodes, exhibit high specific capacity (1261.3 mAh g(-1) at 200 mA g(-1)), high rate capability (with a reversible capacity of approximately 605 mAh g(-1) at 10 A g(-1)), and excellent cyclic stability (with a capacity of over 900 mAh g(-1) during 500 cycles). The superior electrochemical performance of alpha-Fe2O3 nanosheets is attributed to the pseudocapacitive behavior, Al-doping in the alpha-Fe2O3 structure, and improved Li+-transfer property across the (001) facet, as elucidated by first-principles calculations based on density functional theory. These results reveal the underlying mechanism of Li+ transfer across different facets and thus provide insights into the understanding of the excellent electrochemical performance.