<p>The electrochemical performance of lab-scale coin-cell batteries is highly sensitive to assembly parameters, which can lead to significant performance variation and hinder the reproducible screening of novel materials. This study presents the application of Design of Experiments (<i>DoE</i>) methodologies to optimize key assembly parameters in coin-cell lithium-ion batteries employing LiMn₂O₄ cathodes. Specifically, the influence of three assembly variables—crimping pressure (700, 800, and 900&#xa0;kg), number of current collectors (one or two units), and electrolyte volume (30, 50, and 70&#xa0;µl)—was evaluated in terms of their impact on electrochemical impedance and galvanostatic discharge capacity. Analysis of variance (ANOVA) revealed that crimping pressure had the most significant effect on both response variables. Taguchi optimization identified the optimal assembly configuration as a crimping pressure of 800&#xa0;kg, an electrolyte volume of 70&#xa0;µl, and the use of a single current collector. Under these conditions, the battery exhibited the lowest resistance values (<InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(\:{R}_{ct}=590\:{\Omega\:}\)</EquationSource> </InlineEquation>) and the highest discharge capacity (65 mAh g⁻¹). These findings highlight the critical interplay between battery assembly conditions and the functional performance of LiMn₂O₄-based lithium-ion batteries.</p> Graphical Abstract <p></p>