Advanced anode material designs utilizing dual phase alloy systems like Si/FeSi₂ nano-composites show great potential to decrease the capacity degrading and improve the cycling capability for Lithium (Li)-ion batteries. Here, we present a multi-scale characterization approach to understand the (de-)lithiation and irreversible volumetric changes of the amorphous silicon (a-Si)/crystalline iron-silicide (c-FeSi₂) nanoscale phase and its evolution due to cycling, as well as their impact on the proximate pore network. Scattering and 2D/3D imaging techniques are applied to probe the anode structural ageing from nm to μm length scales, after up to 300 charge-discharge cycles, and combined with modeling using the collected image data as an input. We obtain a quantified insight into the inhomogeneous lithiation of the active material induced by the morphology changes due to cycling. The electrochemical performance of Li-ion batteries does not only depend on the active material used, but also on the architecture of its proximity.

利用双相合金系统（如 Si/FeSi ₂纳米复合材料）的先进阳极材料设计在减少锂 (Li) 离子电池的容量退化和提高循环能力方面显示出巨大潜力。在这里，我们提出了一种多尺度表征方法来理解非晶硅 (a-Si)/结晶铁硅化物 (c-FeSi _{2 ) 的（去）锂化和不可逆体积变化}) 纳米级相及其由于循环而发生的演变，以及它们对邻近孔隙网络的影响。应用散射和 2D/3D 成像技术来探测从 nm 到 μm 长度尺度的阳极结构老化，经过多达 300 次充放电循环，并结合使用收集的图像数据作为输入的建模。我们获得了对由循环引起的形态变化引起的活性材料的不均匀锂化的量化洞察。锂离子电池的电化学性能不仅取决于所使用的活性材料，还取决于其邻近结构。