Variance-wise segmentation for a temporal-adaptive SAX

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.