Exploring the role of carbon binder domain morphology in enhancing the electrochemical performance of Li-ion battery
Wei Sun, Chun Huang
Abstract
The electrochemical performance of Li-ion batteries (LIBs) is significantly influenced by electrode microstructure. The carbon and binder domain (CBD) plays an important role as it supports electronic conduction and maintains mechanical integrity. Despite its importance, the impact of CBD morphology on electrochemical performance remains poorly understood. One of the reasons is that CBD requires higher resolution to resolve the nanostructures, and techniques such as most X-ray computed tomography (XCT) machine cannot resolve CBD. This study establishes a workflow that incorporates active material (AM) particles obtained from XCT with numerically generated CBD morphology to build a 3D image-based and physics-resolved model to predict its electrochemical performance. Our model considers both explicit and implicit configurations of dense and nanoporous CBD during the electrochemical modelling process. Results indicate that the interface between AM and electrolyte significantly limits discharge capacity under explicit dense CBD configurations. In contrast, film-coating-like nanoporous CBD could enhance LIB longevity due to locally homogeneous lithiation in AM particles. Our findings also suggest that Li-ion transport is a major limitation in achieving higher (dis)charge rate capacities (5C) under implicit CBD considerations. This study highlights the crucial role of CBD morphology in optimising electrode design for improved battery performance. • Couple XCT imaging and numerically generated carbon binder domain (CBD) morphology. • Explicit and implicit CBD electrochemical simulations. • Analysing impact of CBD morphology on interface area and discharge performance. • Identifying ionic transport limit of CBD at high-rate conditions. • Providing guidance on CBD morphology optimisation for electrode design.