Patent ID: 8852808

Claim:
An electrochemical cell comprising a housing having disposed therewithin an electrolyte, and a multi-layer article at least partially immersed in the electrolyte; wherein the multi-layer article comprises a first metallic current collector, a first electrode material in electrically conductive contact with the first metallic current collector, a second electrode material in ionically conductive contact with the first electrode material, a porous separator disposed between and contacting the first electrode material and the second electrode material, and a second metallic current collector in electrically conductive contact with the second electrode material; wherein the porous separator comprises a nanoweb that comprises a plurality of nanofibers, and the nanofibers consist essentially of a fully aromatic polyimide and wherein the fully aromatic polyimide is characterized by a crystallinity index of 0.11 or greater; wherein the electrolyte comprises an organic solvent and a lithium salt soluble therein; and wherein the solvent comprises propylene carbonate, esters, ethers, or trimethylsilane derivatives of ethylene glycol or poly(ethylene glycols) or combinations of the foregoing.