Tellurium-Polysulfide Chemistry Enables Stable Operation of Lithium-Sulfur Batteries with Limited Lithium Inventory and Electrolyte Supply

摘要

The practical realization of lithium-sulfur (Li-S) batteries with high energy density is currently limited by the poor cyclability of the lithium-metal anode. Lithium plating and stripping in the liquid ether-based electrolyte is irreversible over long-term cycling and this leads to rapid capacity fade. Due to the reducing nature of lithium, parasitic side reactions with the electrolyte also occur with considerable severity during cell operation. This eliminates a significant portion of the available lithium inventory and electrolyte supply, and the cell fails prematurely. These problems can be sidestepped by employing surplus lithium and electrolyte in the cell, but this compromises the stack-level energy density. Stabilizing lithium deposition and reducing electrolyte decomposition is of critical importance to enabling commercially viable Li-S batteries with high energy density and long cycle life.