Mechanistic Validation of Lifetime Prediction for Chlorine Evolution Electrodes Using Accelerated Lifetime Tests

The development of highly durable electrodes for the electrochemical chlorine evolution reaction (CER) at the industrial scale necessitates reliable and practical methods for predicting electrode lifetime. Among these, accelerated lifetime testing (ALT) has emerged as a widely accepted approach for simulating long-term degradation within a shortened time frame. In this study, we evaluated the mechanistic validity of the empirical lifetime prediction model for CER using Ti/Ru 0.3 Sn 0.35 Ti 0.35 O 2 electrodes. Through electrochemical and structural characterization, we confirmed that the major deactivation pathway is the thickening of an insulating oxide interlayer rather than catalyst layer deactivation. By systematically varying current density, temperature, and electrolyte concentration during ALT, we confirmed that the same deactivation mechanism persists across operating conditions, while these parameters modulate the oxidation kinetics of the Ti substrate and thereby govern the overall electrode lifetime. These insights offer a mechanistically grounded and experimentally validated framework for evaluating and optimizing electrode stability under practical operating conditions.