An Advance Additive for High Voltage Capability and Superior Cycle Stability Sodium-Ion Battery

Abstract

There are currently two main issues of sodium ion batteries. Because of sodium has a large Ionic radius, the kinetic process is slow, resulting in poor rate and cycling performance of Sodium-ion battery. Secondly, the Standard electrode potential of sodium (-2.71 V vs. SHE) is higher than that of lithium (-3.04 V vs. SHE), resulting in a lower operating voltage of Sodium-ion battery. Adding additives is effective in forming solid electrolyte interface (SEI) and cathode electrolyte interface (CEI), which is a great method to help solve the above problems. Through physical characterization and theoretical calculations, it was analyzed that the 1,3-Propane sultone (1,3-PS) can effectively participate in the generation of SEI and CEI owing to its reductive potential and Lowest Unoccupied Molecular Orbital (LUMO) energy. Because of lower LUMO energy, the 1,3-PS molecules have higher reduction potentials and occurs reduction reaction on the anode to form a passivation layer film prior to solvent decomposition. In addition, 1,3-PS can also prevent electrolyte oxidation and decomposition, thus improving battery inflation issues.1,3-PS proved to improve performance for high voltage capability and superior cycle stability Sodium-ion battery, achieving of a 96.16% capacity retention and an 5.9% higher discharge specific capacity at 50mA·g-1 than the half battery without the additive. NVP | | HC punch battery was assembled with 1,3-PS of 1000 cycles plating / stripping, achieving a better capacity retention and antioxidant capacity as compared to the punch battery with the blank electrolyte.

Keywords: 1, 3-Propane sultone, Sodium-ion batteries, Lowest Unoccupied Molecular Orbital, Solid and cathode electrolyte interface