3D Imaging and in-operando Tracking of Battery Electrode Microstructures

Abstract

Global demands for energy storage, supply and portability has seen continual increase. Meeting these requirements will be accelerated through an ability to directly image electrochemical devices such as batteries, in 3D, at high resolutions. However, despite their importance, the influence of microstructure on electrode behaviour remains poorly understood. Tomographic techniques allow for direct 3D imaging and chracterisation of complex microstructures down towards tens of nanometers; which are inadequately described in 2D. The performance of battery electrodes are dependent on their inherent nano/micro scale structures where important reactions occur. Microstructural differences in mechanical, electrochemical or transport behaviour at fine length scales ultimately influences cell and pack level performance. Additionally, during processing or operation microstructural evolution may degrade electrochemical performance. Here we utilise tomographic techniques to probe different 3D battery anode structures at high resolutions to capture micro-nanometer length scale structure. The advanced 3D quantification of complex electrode shapes, structures and morphology facilitate an understanding of cell level behaviour. Furthermore, we directly image and track in-operando interfacial and microstructural changes during anode lithiation (Figure 1). In doing so, this provides important insights for electrode design and understanding sources of performance degradation.