Jiang Yao, Yue Ji-Li, Guo Qiubo, Xia Qiuying, Zhou Chong, Feng Tao, Xu Jing, Xia Hui
School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
Herbert Gleiter Institute of Nanoscience, Nanjing University of Science and Technology, Nanjing, 210094, China.
Small. 2018 May;14(19):e1704296. doi: 10.1002/smll.201704296. Epub 2018 Apr 14.
The electrochemical performance of most transition metal oxides based on the conversion mechanism is greatly restricted by inferior cycling stability, rate capability, high overpotential induced by the serious irreversible reactions, low electrical conductivity, and poor ion diffusivity. To mitigate these problems, highly porous Mn O micro/nanocuboids with in situ formed carbon matrix (denoted as Mn O @C micro/nanocuboids) are designed and synthesized via a one-pot hydrothermal method, in which glucose plays the roles of a reductive agent and a carbon source simultaneously. The carbon content, particle size, and pore structure in the composite can be facilely controlled, resulting in continuous carbon matrix with abundant pores in the cuboids. The as-fabricated Mn O @C micro/nanocuboids exhibit large reversible specific capacity (879 mAh g at the current density of 100 mA g ) as well as outstanding cycling stability (86% capacity retention after 500 cycles) and rate capability, making it a potential candidate as anode material for lithium-ion batteries. Moreover, this facile and effective synthetic strategy can be further explored as a universal approach for the synthesis of other hierarchical transition metal oxides and carbon hybrids with subtle structure engineering.
基于转化机制的大多数过渡金属氧化物的电化学性能受到较差的循环稳定性、倍率性能、由严重不可逆反应引起的高过电位、低电导率和差的离子扩散率的极大限制。为了缓解这些问题，通过一锅水热法设计并合成了具有原位形成碳基质的高度多孔MnO微/纳米立方体（表示为MnO@C微/纳米立方体），其中葡萄糖同时充当还原剂和碳源。复合材料中的碳含量、粒径和孔结构可以很容易地控制，从而在立方体内形成具有丰富孔隙的连续碳基质。所制备的MnO@C微/纳米立方体表现出大的可逆比容量（在100 mA g的电流密度下为879 mAh g）以及出色的循环稳定性（500次循环后容量保持率为86%）和倍率性能，使其成为锂离子电池负极材料的潜在候选者。此外，这种简便有效的合成策略可以进一步探索作为一种通用方法，用于合成其他具有精细结构工程的分级过渡金属氧化物和碳杂化物。
