Electrochemical cells operate under dynamical conditions, which are often extremely harsh and diverse, including pressure (P), volume (V), temperature (T), voltage (E), current (I), and frequency (f), in response to the demand of target application fields. Accordingly, a variety of mechanical, thermal, and electrochemical stresses can be exerted to energy storage devices and materials, whose performances and properties are often degraded along with the safety concern. We are focusing on the design parameters of electrode and electrolyte materials adaptable for extreme environments as well as extrinsic behaviors of materials and devices at the limiting operating conditions as below.