多孔MnO@C立方体的制备及电化学性能研究

Preparation and Electrochemical Performance of Porous MnO@C Cube

采用水热法合成了原位葡萄糖包覆的前驱物MnCO_(3),将其煅烧制备出多孔MnO@C微米立方复合材料。利用X射线衍射仪、热重分析仪和扫描电子显微镜对该复合材料的晶体结构和微观形貌进行表征,并探究了MnO@C的电化学性能。结果表明,与未添加葡萄糖相比,MnO@C复合材料电化学性能明显改善。在1 C的电流密度下,经过200次循环,其放电比容量仍达883.7 mAh·g^(-1),容量保持率达95.1%;而在8 C大电流密度下,仍具有236.3 mAh·g^(-1)的放电比容量。葡萄糖的加入和介孔中空立方体结构的结合提高了MnO倍率性能,使其循环性能相对稳定。

In situ glucose-coated MnCO_(3) precursor is synthesized by hydrothermal method and calcined to prepare porous MnO@C micrometer cubic composite material.The crystal structure and micro morphology of the composite are characterized by X-ray diffraction,thermogravimetric analysis and scanning electron microscope.The electrochemical performance of MnO@C is investigated.The results show that the electrochemical performance of the MnO@C composite is significantly improved compared to the pure material without glucose.The discharge specific capacity reaches 883.7 mAh·g^(-1) and the capacity retention rate reaches 95.1% at a current density of 1 C after 200 cycles,while at a large current density of 8 C,it still has a discharge specific capacity of 236.3 mAh·g^(-1).The combination of glucose addition and the hollow mesoporous cubic structure improves the rate performance of MnO and makes its cycling performance relatively stable.