To meet the growing global demand for electronics that can operate for long periods of time, engineers will need to develop highly performing and stable batteries with increasingly longer lifetimes. To reliably continue improving battery technologies, one should ideally be able to continuously monitor the dynamic chemistry inside their cells in real-world operating conditions, to identify potential issues and maximize their performance.To meet the growing global demand for electronics that can operate for long periods of time, engineers will need to develop highly performing and stable batteries with increasingly longer lifetimes. To reliably continue improving battery technologies, one should ideally be able to continuously monitor the dynamic chemistry inside their cells in real-world operating conditions, to identify potential issues and maximize their performance.