Bringing real-time observability to practical aqueous zinc-ion batteries

The practical deployment of aqueous zinc-ion batteries (AZIBs) is limited by the lack of observability of internal electrochemical states. Critical failure processes, including hydrogen evolution, zinc dendrite growth, and cathode dissolution, evolve dynamically and remain inaccessible to conventional battery management systems based on external signals. Here, we highlight a sensing-centric approach that enables real-time observability in working AZIBs. By integrating miniaturized in-situ sensors, key parameters such as internal pressure, pH, and mechanical stress can be directly monitored during operation, providing continuous access to internal battery state evolution. This transforms AZIBs from black box into observable electrochemical systems, enabling early detection of battery failure and safety risks. Coupling multi-modal sensing with data-driven models and digital twins further enables predictive battery management under realistic conditions, offering a pathway toward reliable and scalable AZIB deployment. It can also be applied for Li metal batteries.