Optimizing Compaction Density for Accurate Electrochemical Characterization of Graphite Anodes in Li-ion Simulated Cells

Graphite anodes are critical for lithium-ion batteries, and simulated cells are indispensable tools for their electrochemical evaluation. However, the accuracy of these tests is often compromised by the overlooked parameter of compaction density. This study systematically investigates its impact on performance, interfacial impedance, and structural integrity. We demonstrate an optimal density range for consistent measurements of specific capacity and Coulombic efficiency. Excessive compaction degrades performance and increases data scatter, due to particle cracking, fresh surface exposure, increased side reactions, and hindered ion diffusion, as supported by SEM and EIS-DRT analysis. These findings provide pivotal guidelines for standardizing testing protocols and optimizing manufacturing processes.