| Autor: |
Ziqi Wang, Guodong Qian, Yuanjing Cui, Yu Yang, Zhiyu Wang, Buxue Wang, Banglin Chen |
| Rok vydání: |
2015 |
| Předmět: |
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| Zdroj: |
Microporous and Mesoporous Materials. 203:86-90 |
| ISSN: |
1387-1811 |
| DOI: |
10.1016/j.micromeso.2014.10.026 |
| Popis: |
To make use of a metal–organic framework MIL-101(Cr 3+ ) as template and core generator, we report synthesis of a novel nanoscale yolk/shell octahedron of Cr 2 O 3 @TiO 2 and its high performance as the anode material for lithium ion battery. Nanoscale MIL-101(Cr 3+ ) was coated with amorphous TiO 2 shell and calcinated under Ar and then in air atmospheres to form nanoscale Cr 2 O 3 @TiO 2 . After heat treatment, the amorphous TiO 2 coated MIL-101(Cr) was transformed into nanosized Cr 2 O 3 crystals with crystalline TiO 2 cover, forming multicore yolk/shell octahedrons, as demonstrated from their SEM and TEM morphologies. The resulting Cr 2 O 3 @TiO 2 has moderate porosity with the BET surface area of 146 m 2 g −1 , and the diameter of its Cr 2 O 3 cores is 10–40 nm. It has demonstrated a reversible capacity of 510 mA h g −1 after 500 cycles at 0.5 C charge/discharge rate, which is much better than the bare nano Cr 2 O 3 without TiO 2 shell, and is one of the best-performed Cr 2 O 3 anode materials. The improved electrochemical performance of Cr 2 O 3 @TiO 2 is attributed to its small particle size with moderate porosity for the infiltration of electrolyte and the fast diffusion of Li + ions, its void space within yolk/shell structure to buffer volumetric variation of Cr 2 O 3 and its TiO 2 shell to restrain pulverized inner particles. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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