Hot embossing of thick Li-ion battery electrodes for improved rate capability and cycling stability

The development of high areal capacity electrodes with a long cycle life is crucial for next-generation Li-ion batteries. Numerous structuring strategies—ranging from bottom-up active material self-assembly to top-down electrode patterning — have been proposed to enhance ion transport and mitigate mechanical degradation in thick electrodes. However, these approaches often suffer from limited compatibility with roll-to-roll manufacturing or result in significant material wastage, constraining their industrial adoption. Here, we present hot embossing as a simple and scalable structuring strategy for thick electrodes. This work provides an analysis of the fundamental considerations governing hot embossing of electrode architectures, establishing a balanced assessment of opportunities and limitations of the technology. By varying the embossing parameters, binder and mould designs, we identify process conditions leading to high moulding fidelity and improvements in both rate capability and cycling stability. We also show that embossing can lead to non-uniform pore distributions in electrodes and shear alignment of active-material particles that can lead to poor rate performance. Overall, this work shows that hot embossing can enhance the performance of high-areal-loading electrodes, but that the outcome depends on the binder, active material, mould geometry and embossing parameters, and is therefore not universally beneficial.