Rational Design of a Low-Solvating Non-Flammable Electrolyte for Na-ion/metal Batteries.

Abstract

Exponential reduction in Lithium reserves is an alarming indicator for requirement of alternate energy storage solutions to reduce the dependency on Lithium-ion Batteries. Sodium-ion batteries are considered as the most-promising replacement to Lithium-ion batteries. Electrolytes are the major components of the battery that contribute to its safety. Electrolyte is the major component of the battery that contributes to its safety. Most commercial LIBs have safety issues due to flammable electrolyte. SIBs in order to be better than LIBs need to be non-flammable in nature. The resulting two decades of research on electrolytes for SIBs have focused on this aspect, while not compromising on the performance. Therefore, research on electrolytes has relied on the SEI theory to optimize the components of electrolytes. This thesis focuses on developing a low-solvating and a non-flammable electrolyte with exceptional cycling stability. The NVP||Na cells of the designed non-flammable electrolytes had a capacity fading of only 3% after 75 cycles as of now in comparison to 70% capacity fading of the base electrolyte within the above-mentioned number of cycles. This project also involved the synthesis of Battery-grade Sodium Hexafluorophosphate (NaPF6 salt) due to its poor-quality commercial supply. The yield was calculated to be more than 96%.