Kang Qiaoling, Qin Yezhi, Shi Jiangwei, Xiong Boru, Tang Wenying, Gao Feng, Lu Qingyi
College of Materials and Chemistry, China Jiliang University, Hangzhou 310018, PR China; State Key Laboratory of Coordination Chemistry, Coordination Chemistry Institute, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, PR China.
Department of Materials Science and Engineering, Jiangsu Key Laboratory of Artificial Functional Materials, Collaborative Innovation Center of Advanced Microstructures, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210023, PR China.
J Colloid Interface Sci. 2022 Sep 15;622:780-788. doi: 10.1016/j.jcis.2022.04.151. Epub 2022 Apr 30.
The design and synthesis of hollow-nanostructured transition metal oxide-based anodes is of great importance for long-term operation of lithium ion batteries (LIBs). Herein, a special hollow bowl-like α-FeO nanostructure is controllably synthesized through a facile hydrothermal technique and exhibits great electrochemical lithium storage performance when used as LIBs anode. Under a facile hydrothermal condition, α-FeO nanostructures evolve from solid pie-like structure to hollow bowl-like structure and finally α-FeO nanorings through the regulation of HPO derived from ionized NaPO·12HO and Ostwald ripening process. The designed hollow bowl-like α-FeO nanostructure not only has the merits of hollow structure, which can accelerate the diffusion of lithium ions and electrons, but also shows great mechanical strength to disperse stress when compared to solid pie-like and ring-like α-FeO nanostructures, which would avoid collapse during charge/discharge process. As a result, the as-synthesized hollow bowl-like α-FeO nanostructure displays an initial reversible capacity of 1616 mAh g at a current density of 1 A g, an excellent cycling performance with a reversible capacity of 1018 mAh g after 500 cycles and an outstanding rate capability (68.1% capacity retention at current densities from 100 to 2000 mA g). This work provides not only a novel hollow bowl-like α-FeO nanostructure with high specific surface area and stable structure as potential electrode materials for energy storage, but also a facile self-templated strategy free of any surfactants and templates for hollow nanostructures.
中空纳米结构过渡金属氧化物基负极的设计与合成对于锂离子电池（LIBs）的长期运行至关重要。在此，通过简便的水热技术可控地合成了一种特殊的中空碗状α-FeO纳米结构，当其用作LIBs负极时表现出优异的电化学锂存储性能。在简便的水热条件下，α-FeO纳米结构通过对源自电离的NaPO·12HO的HPO的调控以及奥斯特瓦尔德熟化过程，从实心饼状结构演变为中空碗状结构，最终形成α-FeO纳米环。所设计的中空碗状α-FeO纳米结构不仅具有中空结构的优点，能够加速锂离子和电子的扩散，而且与实心饼状和环状α-FeO纳米结构相比，还表现出极大的机械强度以分散应力，这将避免在充放电过程中发生坍塌。结果，所合成的中空碗状α-FeO纳米结构在电流密度为1 A g时显示出1616 mAh g的初始可逆容量，在500次循环后具有1018 mAh g的可逆容量的优异循环性能以及出色的倍率性能（在100至2000 mA g的电流密度下容量保持率为68.1%）。这项工作不仅提供了一种具有高比表面积和稳定结构的新型中空碗状α-FeO纳米结构作为潜在的储能电极材料，而且还提供了一种无需任何表面活性剂和模板的简便自模板策略用于制备中空纳米结构。
