Comparative characteristic evaluation of commercial sensors for organic solvent leakage detection in renewable energy and secondary battery applications

This study was conducted to quantitatively evaluate the performance and characteristic behavior of leakage detection sensors under controlled laboratory conditions, motivated by potential organic solvent leakage incidents in renewable energy and secondary battery applications. Three types of sensors—film-type, separate point-type, and integrated point-type—were tested using target substances including organic carbonate electrolytes such as dimethyl carbonate (DMC) and ethyl methyl carbonate (EMC), as well as sulfuric acid and sodium hydroxide. The evaluation focused on changes in capacitance and the reusability of each sensor. Unlike previous capacitance-based solvent detection studies that relied on laboratory-prepared samples or novel sensing materials, this work provides a systematic comparison of commercially available sensor architectures under realistic industrial carbonate-solvent leakage scenarios.The integrated point-type sensor demonstrated reliable capacitance-based detection and formed a consistent capacitance range for each type of organic solvent. Specifically, DMC and EMC showed stable values around 83.0 pF and 80.5 pF, respectively, which reflects differences in their dielectric-related behavior and indicates potential applicability for qualitative material identification. Moreover, this sensor maintained performance within ±5% deviation after drying, thereby verifying excellent reusability.In contrast, the film-type sensor could only detect changes in resistance and was not reusable. The separate point-type sensor did not provide quantitative measurements but proved feasible for repeated leakage alerts through buzzer alarms. However, the capacitance response rapidly saturated after initial wetting (k → 0), indicating that the method is inherently suitable for qualitative identification rather than quantitative leakage estimation.These results indicate that the integrated point-type sensor is a promising option for qualitative detection of organic solvent leakage. By comparing the capacitance response ranges, repeatability, precision, and stability of each sensor type, this study provides foundational data for developing future alarm systems based on qualitative material identification and supporting the future development and validation of sensor-based leakage monitoring technologies.