Brookhaven National Laboratory, Upton, NY, 11973, USA.
Institute of Physics, Academia Sinica, Taipei, 11529, Taiwan.
Angew Chem Int Ed Engl. 2017 Jun 26;56(27):7813-7816. doi: 10.1002/anie.201703168. Epub 2017 May 29.
Lithiation/delithiation induces significant stresses and strains into the electrodes for lithium ion batteries, which can severely degrade their cycling performance. Moreover, this electrochemically induced strain can interact with the local strain existing at solid-solid interfaces. It is not clear how this interaction affects the lithiation mechanism. The effect of this coupling on the lithiation kinetics in epitaxial Fe O thin film on a Nb-doped SrTiO substrate is investigated. In situ and ex situ transmission electron microscopy (TEM) results show that the lithiation is suppressed by the compressive interfacial strain. At the interface between the film and substrate, the existence of Li Fe O rock-salt phase during lithiation consequently restrains the film from delamination. 2D phase-field simulation verifies the effect of strain. This work provides critical insights of understanding the solid-solid interfaces of conversion-type electrodes.
锂化/脱锂会在锂离子电池的电极中引起显著的应力和应变，从而严重降低其循环性能。此外，这种电化学诱导的应变可以与固-固界面处存在的局部应变相互作用。目前尚不清楚这种相互作用如何影响锂化机制。本研究考察了在掺铌 SrTiO 衬底上外延 FeO 薄膜中的锂化动力学的这种耦合效应。原位和非原位透射电子显微镜（TEM）结果表明，压应变界面抑制了锂化。在薄膜和衬底之间的界面处，锂化过程中存在 LiFeO 岩盐相，从而阻止了薄膜分层。二维相场模拟验证了应变的作用。这项工作提供了对转换型电极固-固界面的深入理解。
