Potential complexes of NaCF3SO3-tetraethylene dimethyl glycol ether (tetraglyme)-based electrolytes for sodium rechargeable battery application

摘要

The increasing energy demand on available global lithium resources has created concerns on development of new and advanced sustainable energy sources. Sodium-based batteries have emerged as promising substitutions to Li-based batteries. We describe here sodium trifluoromethanesulfonate (NaCF3SO3) electrolyte system based on tetraethylene glycol dimethyl ether (tetraglyme). The ionic conductivity of the electrolytes showed a maximum value of 1.6mScm(-1) for 40mol% of NaCF3SO3 at room temperature and increased up to of 9.5mScm(-1) at 373K. The system showed the anodic stability of the electrolytes up to ca. 5.2V (Na+/Na) and facile deposition of sodium began at relatively low overpotential, around -0.01V vs. Na+/Na, which showed a good reversibility of the electrolytes. Preliminary tests of the electrolyte in half sodium-ion cells employing Na3V2(PO4)(3) as cathode electrodes were performed and the cells delivered capacity of 74mAhg(-1) at C/10.