α-FeO with novel double hexagonal pyramid morphology synthesized using a dual-ion co-work system as an anode for lithium-ion batteries

In this study, α-Fe 2 O 3 particles with novel double hexagonal pyramid morphology were synthesized via a facile hydrothermal method in a rare system of coexisting ammonium ions (NH 4+ ) and carbonate ions (CO 3 2− ), which was different from the previously used single-ion inducing system. A series of experimental results indicated that the synergistic effects of NH 4+ and CO 3 2− played a decisive role in the formation process of α-Fe 2 O 3 particles with the unique morphology, and the formation mechanism was attributed to the oriented aggregation and Ostwald ripening process. When utilized as anode materials for LIBs, the α-Fe 2 O 3 particles with the double hexagonal pyramid morphology exhibited the excellent cycling stability of 700 mA h g −1 after 100 charge/discharge cycles with the high coulombic efficiency of 98% starting from the 25th cycle; this indicated that these particles could be a promising alternative anode for LIBs. α-Fe 2 O 3 particles with double hexagonal pyramid morphology were synthesized via hydrothermal method in the system of coexisting NH 4 + and carbonate ions CO 3 2− , which was different from the previously used single-ion inducing system.