Abstract: The present disclosure a gel polymer electrolyte for an electrochemical cell that cycles lithium ions. The gel polymer electrolyte includes a polymer host, a liquid electrolyte, and greater than or equal to about 0.1 wt. % to less than or equal to about 10 wt. % of a sulfolene additive. In certain variations, the gel polymer electrolyte also includes greater than or equal to about 0.1 wt. % to less than or equal to about 5 wt. % of an ethylene carbonate additive. The ethylene carbonate additive may be selected from the group consisting of: vinyl ethylene carbonate (VEC), fluoroethylene carbonate (FEC), vinylene carbonate, and combinations thereof. In each instance, the lithium electrolyte may include a first lithium salt, a second lithium salt that is distinct from the first lithium salt, and a third lithium salt that is distinct from the first lithium salt and the second lithium salt.