Cathode Dissolution as a Battery Failure Mechanism in Silver Vanadium Oxide (SVO) and Structurally-Stabilized SVO-Analogue Materials Using Phosphate (PO43-)

The detailed understanding of non-Faradaic parasitic reactions which diminish battery calendar life is essential to the development of effective batteries for use in long life applications.  The dissolution of cathode materials including manganese, cobalt and vanadium oxides in battery systems has been identified as a battery failure mechanism, yet detailed dissolution studies including kinetic analysis are absent from the literature.  The results presented provide a framework for the quantitative and kinetic analyses of the dissolution of cathode materials which will aid the broader community in more fully understanding this battery failure mechanism.

In this study, a series of vanadium oxide and phosphate based cathode materials are studied relative to their dissolution in battery electrolyte.  Kinetic analysis of the results provides a quantitative framework for rationalizing the impact of structure and composition on dissolution.  Further, the result of cathode solubility at the systems level is investigated shedding light on the interaction of the negative electrode with the dissolved transition metal species.  The findings are used to provide a conceptual model for the resultant impedance rise.