A flexible small-scale electrochemical flow cell.

Reproducible electrochemical characterization in bench-scale flow cells remains limited by variability in cell architecture, assembly practices, and operating conditions across users and laboratories. Although numerous cell designs have been reported, comprehensive guidance detailing component selection, fabrication, assembly, and testing protocols is largely absent. Here, we present a compact flow cell, engineered to improve experimental rigor while maintaining architectural flexibility and cost-effectiveness. The platform incorporates interchangeable components, enabling adaptation to diverse electrochemical applications including redox flow batteries, electrolyzers, and fuel cells, with additional modifications and ancillary balance of plant where necessary. The small scale of the device lowers volume and area requirements for electrolytes and cell components, respectively, facilitating high-throughput, yet systematic studies of emerging chemistries and materials. As a representative use case, we characterize cell performance using two diagnostic configurations and a model redox electrolyte, common in flow battery literature. We also present a framework distinguishing marginal and total repeatability to quantify variability across independent cell builds and operators. Using cell polarization and galvanostatic cycling protocols, we demonstrate consistent performance across configurations and users. By coupling transparent design documentation with a quantitative repeatability framework, this work seeks to establish a reproducible foundation for bench-scale flow cell experimentation and to support cross-laboratory comparability in electrochemical research.