Slurry process optimization through rheological investigation for electrochemical capacitors

Abstract

Electrode manufacturing is energy demanding and environmentally harmful, requiring a shift towards aqueous-processing and more efficient energy management. Slurry mixing, a critical stage in electrode production, determines the quality of the coating, ultimately shaping the electrochemical performance. Quality control of slurry mixing is typically performed through rheological analysis. Additionally, the monitoring of the rheological evolution reveals the underlying dispersing mechanisms but also the state of mixing, required for process optimization. To promote process sustainability and efficiency, aqueous-processed slurries for Electric Double Layer Capacitors (EDLCs) were analyzed rheologically to investigate the state of dispersion in order to minimize the energy consumption and prevent overmixing. Optimization through rheology resulted in a 35% reduction in processing time while producing electrodes with better mechanical strength, achieving electrochemical performances comparable to standard ones with improved rate capabilities. This method is not only cost-effective but is also transversal to other electrochemical energy storage technologies relying on wet mixing, offering significant benefits in terms of time savings and energy efficiency.