Sodium Vanadium Oxide (NVO) Material Properties—Impact on Electrochemistry and Functional Properties in Zn-Ion Aqueous Batteries

<br/>Implementation of intermittent renewable energy sources derived from wind and solar power provides interest in the development of safe, sustainable, low cost energy storage including batteries based on aqueous electrolytes. Zn as a negative electrode has a high theoretical capacity (820 mAh/g), low redox potential (-0.76 V vs. SHE), and low toxicity with a voltage window suitable for use with aqueous electrolytes<br/>Vanadium based materials are appealing for aqueous electrochemical energy storage due to the multiple accessible redox states for the vanadium center. Layered vanadates are of interest for Zn-ion batteries as the vanadium redox center allows for high capacity and the layered structure promotes facile ion transfer. In particular, sodium vanadium oxides (NVO) show promise as cathode materials for Zn-ion aqueous batteries. Understanding the parameters that govern the charge storage mechanisms of the Zn/NVO aqueous systems remains of key interest where investigations that tune material properties can provide insight toward ultimately controlling electrochemical outcomes in Zn/NVO systems. Materials properties, their impact on functional electrochemistry such as capacity delivery and capacity retention were determined using methods including synchrotron based x-ray absorption analysis and will be discussed.