Su Xiaoru, Huang Jian, Yan Bangyuan, Hong Zhouping, Li Siyuan, Pang Baocheng, Luo Yulin, Feng Li, Zhou Mingjiong, Xia Yongyao
School of Materials Science and Chemical Engineering, Ningbo University Ningbo Zhejiang 315211 P. R. China
State Key Laboratory of Chemical Engineering, Institute of Pharmaceutical Engineering, College of Chemical and Biological Engineering, Zhejiang University Hangzhou Zhejiang 310027 P. R. China.
RSC Adv. 2018 Sep 6;8(55):31388-31395. doi: 10.1039/c8ra05871g. eCollection 2018 Sep 5.
ZnMnO has attracted enormous attention as a novel anode material for rechargeable lithium-ion batteries due to its high theoretical capacity. However, it suffers from capacity fading because of the large volumetric change during cycling. Here, porous ZnMnO yolk-shell microspheres are developed through a facile and scalable synthesis approach. This ZnMnO can effectively accommodate the large volume change upon cycling, leading to an excellent cycling stability. When applying this ZnMnO as the anode in lithium-ion batteries, it shows a remarkable reversible capacity (400 mA h g at a current density of 400 mA g and 200 mA h g at 6400 mA g) and excellent cycling performance (540 mA h g after 300 cycles at 400 mA g) due to its unique structure. Furthermore, a novel conversion reaction mechanism of the ZnMnO is revealed: ZnMnO is first converted into intermediate phases of ZnO and MnO, after which MnO is further reduced to metallic Mn while ZnO remains stable, avoiding the serious pulverization of the electrode brought about by lithiation of ZnO.
由于具有高理论容量，ZnMnO作为一种新型的可充电锂离子电池负极材料引起了广泛关注。然而，由于其在循环过程中存在较大的体积变化，导致容量衰减。在此，通过一种简便且可扩展的合成方法制备了多孔ZnMnO蛋黄壳微球。这种ZnMnO能够有效地适应循环过程中的大体积变化，从而具有出色的循环稳定性。当将这种ZnMnO用作锂离子电池的负极时，由于其独特的结构，它表现出显著的可逆容量（在电流密度为400 mA g时为400 mA h g，在6400 mA g时为200 mA h g）和优异的循环性能（在400 mA g下循环300次后为540 mA h g）。此外，还揭示了ZnMnO的一种新型转化反应机制：ZnMnO首先转化为ZnO和MnO的中间相，之后MnO进一步还原为金属Mn，而ZnO保持稳定，避免了由ZnO锂化导致的电极严重粉化。
