Ti-based reference electrodes for inline implementation into Lithium-ion pouch cells

Despite growing demand for Li-ion batteries in the portable, industrial, and electric vehicle markets, the performance and safety monitoring of these state-of-the-art rechargeable cells is quite limited, relying on conventional full-cell measurements with in situ reference electrode technologies lagging behind in application. Herein, for the first time a long-term (>2000 h) stable Ti-based reference electrode is reported, and a new design enabling impact-free implementation into pouch. The methodology can also be used with other reference electrode materials. Various electrochemical characterization techniques are used to verify the usability and stability of the developed reference electrode, in turn enabling monitoring of individual electrode cycling performance and open circuit potential (OCP) via the galavanostatic intermittent titration technique (GITT) and differential capacity analysis. The findings offer a potential way of incorporating stable in situ reference electrodes into current and future generations of lithium-ion batteries.