Suppression of Polysulfide Dissolution and Shuttling with Glutamate Electrolyte for Lithium Sulfur Batteries

Abstract

The lithium sulfur battery is regarded as a potential next-generation high-energy battery system. However, polysulfides dissolve and shuttle through the electrolytes, causing rapid capacity decay, serious self-discharge, and poor high-temperature performances. Here, we demonstrate that by directly introducing glutamate into commercial electrolytes, these issues can be tackled simultaneously. With abundant negatively charged hydroxyl groups, the glutamate additive electrolyte effectively suppresses the shuttling of negatively charged polysulfide ions through strong repulsive interaction up to 1.54 eV. With glutamate additive electrolyte, the lithium sulfur battery has a capacity retention of 60% after 1000 cycles at 5.95 mA/cm2, a self-discharge rate on the order of one-third that of commercial electrolytes, and stable operation at 60 °C.