Zhaomin Wang,Yong Cheng,Qian Li,Limin Chang,Limin Wang
Metallic Sb is deemed as a promising anode material for lithium ion batteries (LIBs) due to its flat voltage platform and high security. Nevertheless, the limited capacity restricts its large-scale application. Therefore, a simple and effective method to explore novel antimony trioxide with high capacity used as anode material for LIBs is imperative. In this work, we report a facile and efficient strategy to fabricate 1D hollow Sb 2 O 3 @TiO 2 composites by using the Kirkendall effect . When used as an anode material for LIBs, the optimal Sb 2 O 3 @TiO 2 composite displays a high reversible discharge capacity of 593 mAh g −1 at a current density of 100 mA g −1 after 100 cycles and a relatively superior discharge capacity of 439 mAh g −1 at a current density of 500 mA g −1 even after 600 cycles. In addition, a reversible discharge capacity of 334 mAh g −1 can also be obtained even at a current density of 2000 mA g −1 . The excellent cycling stability and rate performance of the Sb 2 O 3 @TiO 2 composite can be attributed to the synergistic effect of TiO 2 shell and hollow structure of Sb 2 O 3 , both of which can effectively buffer the volume expansion and maintain the integrity of the electrode during the repeated charge-discharge cycles.
Electrode materials with hollow micro/nanostructures and high electrical conductivity are important for achieving high-power supercapacitors, especially those with super-fast charging/discharging. TiN, which can be easily obtained from TiO2, is regarded as a high-power supercapacitor material. Here, we report that a nanoscale Kirkendall effect is triggered by surface branches on TiO2 nanowires, which then transform into hollow TiN nanotrees during a thermal nitridation process. The surface branches play a key role in accelerating the initial reaction, which forms a uniform, continuous surface TiN layer and induces the Kirkendall effect via surface diffusion. The hollow TiN nanotrees have a high surface area, porous structure, and high electrical conductivity. The constructed symmetric supercapacitors exhibit high areal and volumetric energy density, super-fast charge/discharge ability, and good capacitance retention up to 350 000 cycles. This work provides a new method to synthesize hollow TiN nanostructures and demonstrates their advantages in achieving high-power energy storage devices.
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