Safety shutdown separators

摘要

The present invention pertains to electrochemical cells which comprise (a) an anode; (b) a cathode; (c) a solid porous separator, such as a polyolefin, xerogel, or inorganic oxide separator; and (d) a nonaqueous electrolyte, wherein the separator comprises a porous membrane having a microporous coating comprising polymer particles which have not coalesced to form a continuous film. This microporous coating on the separator acts as a safety shutdown layer that rapidly increases the internal resistivity and shuts the cell down upon heating to an elevated temperature, such as 110° C. Also provided are methods for increasing the safety of an electrochemical cell by utilizing such separators with a safety shutdown layer.

主权项

1. An electrochemical cell comprising:
(i) an anode; (ii) a cathode; (iii) a solid porous separator; and (iv) a nonaqueous electrolyte, wherein said separator and said electrolyte are interposed between said anode and said cathode;
and wherein said separator comprises an inorganic oxide separator layer having a microporous coating on one side of said separator layer, wherein said microporous coating comprises styrenated acrylic polymer particles having a diameter of between 100 and 150 nm.