A novel hierarchical star-like (0304 was successfully synthesized from self-assembled hierarchical Co(OH)F
precursors via a facile hydrothermal method and subsequent annealing in air. The morphological evolution
process of the Co(OH)F precursors was investigated by examining the different reaction times during
synthesis. First, hexagonal plates are formed, and then nanodiscs grow on the surface of the plates.
Subsequently, dissolution and regrowth of Co(OH)F occur to form the star-like hierarchical structures.
(0304 obtained from thermal decomposition of the (o(OH)F precursor in air at 350 O( exhibited high
reversible capacity as an anode material in lithium ion batteries. The specific charge capacity of
1036 mA h g-1 was obtained in the first cycle at a current density of 50 mA g- 1, and after 100 cycles,
the capacity retention was nearly 100%. When the current density was increased to 500 mA g-1 and
2 A g- 1, the capacities were 995 and 641 mA h g-1, respectively, after 100 cycles. In addition, a capacity
of 460 mA h g-1 was recorded at a current density of lOA g-1 in the rate capability test. The excellent
electrochemical performance of the (0304 electrodes can be attributed to the porous interconnected
hierarchical nanostructures, which protect the small particles from agglomeration and buffer the
volume change during the discharge-charge process.