A Multi-Modal Test System for Electro-Thermal-Mechanical Characterisation of Hybrid Solid-State Batteries

This paper presents the development and validation of a multi-functional system for the electro-thermal-mechanical characterization of hybrid solid-state batteries (HSSBs). The platform is specifically engineered to decouple mechanical influences from electrical and thermal responses, enabling detailed investigations into how externally applied forces affect battery performance. At its core is a precision-controlled clamping mechanism that applies and sustains predefined mechanical loads while simultaneously acquiring real-time measurement data. The system architecture accommodates static and dynamic loading modes, supporting in-situ analysis of state-of-charge (SOC)-dependent behaviors, temperature-induced deformation, and force relaxation dynamics. Validation experiments on commercial HSSB cells confirm the system’s high repeatability and uncover distinct electro-thermal-mechanical signatures associated with varying levels of mechanical bias. This platform offers a systematic and decoupled approach to studying the complex, interdependent phenomena governing solid-state battery operation, providing critical insights for material assessment, cell design optimization, and application-oriented modeling.