Understanding Electrode-Electrolyte Solution Interactions Between TiO 2 Nanotube Electrode and Nonaqueous Electrolytes for Sodium-Ion Batteries

Sodium-ion battery technology presents a promising sustainable alternative to the current dominating lithium-ion battery technology due to its low cost associated with its high earth abundance. It has been shown that the interfacial chemistry between anodes and sodium-based or lithium-based electrolytes have markedly different effect even when using the same solvent. It is important to investigate sodium-based electrolytes and to elucidate the mechanisms of electrode and electrolyte interactions. The design and development of next generation electrolytes for sodium-ion batteries is catered towards the improved performance based on evaluation of thermodynamic /transport properties, chemical and electrochemical stability, thermal stability and interfacial chemistry. In this work, we have investigated the electrochemical properties of TiO 2 nanotube electrode in various electrolytes containing different solvent mixtures (cyclic, acyclic carbonates) with NaClO 4 1 salt and NaPF 6 salt and have found that the interaction between the TiO 2 NT electrode and the nonaqueous electrolytes plays a critical role in the charging/discharging processes. In addition, we have conducted fundamental studies of the chosen sodium-based electrolytes on their chemical stability, thermal stability and electrochemical stability. References: Kamath, G.; Cutler, R.; Deshmukh, S. A.; Shakourian-Fard, M.; Parrish, R.; Huether, J.; Butt, D.; Xiong, H.; Sankaranarayanan, S. K. R. S., In Silico Based Rank-Order Determination and Experiments on Non-Aqueous Electrolytes for Sodium Ion Battery Applications. J. Phys. Chem. C 2014, 118, 13406−13416