PART I: NON-TECHNICAL SUMMARY Electrochemical ion insertion into inorganic metal oxide materials is an important mechanism that can enable energy storage, smart window, electronic, and environmental technologies. If the host materials are vanadium oxides, electrochemical insertion of ions can change their structure and properties in ways that are useful for such applications. Doing so from aqueous electrolytes is attractive from the standpoint of safety, sustainability, and scalability. However, vanadium oxides tend to degrade in water, making their use in aqueous systems challenging. This research, with support from the Solid State and Materials Chemistry program in NSF’s Division of Materials Research, takes a new approach to improving the stability of vanadium oxides in water. The research team introduces small amounts of other transition metals into vanadium oxides, using a method known as heteroatom doping. This improves the stability of vanadium oxides in aqueous electrolytes and encourages the desired ion insertion behavior. The project utilizes advanced in-situ electrochemical tools to investigate how the structure and composition of heteroatom-doped vanadium oxides influence their charging mechanism and, consequently, their electrochemical performance. The project brings together researchers from the United States and Israel with complementary expertise and will train students in both countries in state-of-the-art solid-state materials electrochemistry. The knowledg