Three-dimensionally Ordered Macroporous β-Bi₂O₃ with Enhanced Electrochemical Performance in a Li-ion Battery

This paper describes a modified colloidal crystal templating method to prepare three-dimensionally ordered macroporous (3DOM) β-Bi₂O₃. The 3DOM β-Bi₂O₃ materials exhibit higher specific capacities and better capacity retention than conventional β-Bi₂O₃ nanoparticles as anode materials for Li-ion batteries. The initial discharge capacity of 3DOM β-Bi₂O₃ was as high as 1296 mA h g⁻¹ and the fourth discharge capacity was 526 mA h g⁻¹, whereas the discharge capacity of conventional non-templated β-Bi₂O₃ was only 299 mA h g⁻¹ after 4 cycles at a current rate of 0.2C. The improved electrochemical behavior of the 3DOM β-Bi₂O₃ electrodes is attributed to the 3DOM architecture, which provides easy access for Li⁺ ions to the surface of active material nanoparticles and short diffusion paths within the macropore walls, and also to the unique tunnel structure of β-Bi₂O₃.