Wagemaker Marnix, Borghols Wouter J H, Mulder Fokko M
Department of Radiation, Radionuclides and Reactors, Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, 2629 JB Delft, The Netherlands.
J Am Chem Soc. 2007 Apr 11;129(14):4323-7. doi: 10.1021/ja067733p. Epub 2007 Mar 16.
Insertion reactions are of key importance for Li ion and hydrogen storage materials and energy storage devices. The particle size dependence of insertion reactions has been investigated for lithiated anatase TiO2, revealing progressively increasing Li capacity and Li-ion solubility for decreasing particle sizes, strongly deviating from the expected Li-rich and Li-poor phase separation as occurs in the bulk material. The phase diagram alters significantly, changing the materials properties already at sizes as large as 40 nm. A rationale is found in the surface strain that occurs between the different intercalated phases, which becomes energetically too costly in small particles. In particular the observed particle size-induced solid solution behavior is expected to have fundamental and practical implications for two-phase lithium or hydrogen insertion reactions.
插入反应对于锂离子和储氢材料以及储能装置至关重要。已对锂化锐钛矿型TiO₂的插入反应的粒径依赖性进行了研究，结果表明，随着粒径减小，锂容量和锂离子溶解度逐渐增加，这与块状材料中预期的富锂和贫锂相分离有很大偏差。相图发生了显著变化，在粒径大至40 nm时就已改变了材料性能。在不同插入相之间出现的表面应变中找到了一个合理的解释，这种表面应变在小颗粒中能量成本过高。特别是观察到的粒径诱导固溶体行为预计对两相锂或氢插入反应具有重要的理论和实际意义。
