Xu Yuhui, Zhang Gaini, Zhang Jianhua, Wang Xiaoxue, Wang Jingjing, Jia Shuting, Yuan Yitong, Yang Xiaoli, Xu Kaihua, Wang Chunran, Zhang Kun, Li Wenbin, Li Xifei
Shaanxi International Joint Research Center of Surface Technology for Energy Storage Materials, Institute of Advanced Electrochemical Energy & School of Materials Science and Engineering, Xi'an University of Technology, Xi'an 710048, China; Engineering Research Center of Conducting Materials and Composite Technology, Ministry of Education, Xi'an 710048, China.
GEM Co., Ltd., Shenzhen 518101, China.
J Colloid Interface Sci. 2023 Dec 15;652(Pt A):305-316. doi: 10.1016/j.jcis.2023.08.084. Epub 2023 Aug 12.
MnO cathode materials have presented challenges due to their poor conductivity, unstable structure, and sluggish diffusion kinetics for aqueous zinc-ion batteries (AZIBs). In this study, a nanostructured MnO cathode material was synthesized using an acid etching method, Which introduced abundant Mn(III) sites, resulting in the formation of numerous oxygen vacancies. Comprehensive characterizations revealed that these oxygen vacancies facilitated the reversible adsorption/desorption of Zn ions and promoted efficient electron transfer. In addition, the designed mesoporous structure offered ample active sites and shortened the diffusion path for Zn and H ions. Consequently, the nanosized MnO cathode exhibited enhanced reaction kinetics, achieving a considerable reversible specific capacity of 388.7 mAh/g at 0.1 A/g and superior durability with 72.0% capacity retention over 2000 cycles at 3.0 A/g. The material delivered a maximum energy density of 639.7 Wh kg at 159.94 W kg. Furthermore, a systematic analysis of the zinc storage mechanism was performed. This work demonstrates that engineering oxygen vacancies with nanostructure regulation provides valuable insights into optimizing MnO cathode materials for AZIBs.
由于其导电性差、结构不稳定以及水系锌离子电池（AZIBs）的扩散动力学迟缓，MnO阴极材料面临诸多挑战。在本研究中，采用酸蚀刻法合成了一种纳米结构的MnO阴极材料，该方法引入了丰富的Mn(III)位点，从而形成了大量氧空位。综合表征表明，这些氧空位促进了锌离子的可逆吸附/脱附，并促进了有效的电子转移。此外，设计的介孔结构提供了充足的活性位点，并缩短了锌离子和氢离子的扩散路径。因此，纳米MnO阴极表现出增强的反应动力学，在0.1 A/g时实现了388.7 mAh/g的可观可逆比容量，以及在3.0 A/g下2000次循环后72.0%的容量保持率的优异耐久性。该材料在159.94 W/kg时的最大能量密度为639.7 Wh/kg。此外，还对锌存储机制进行了系统分析。这项工作表明，通过纳米结构调控来设计氧空位为优化用于AZIBs的MnO阴极材料提供了有价值的见解。
