US Patent 9905860 Water activated battery system having enhanced start-up behavior

A water activated lithium battery cell having a thermal agent component for warming up cell components upon deployment. Also a water-activated battery system that is adapted to operate in and/or on the surface of a waterbody (i.e., a body of water including those which are natural or man made). In various embodiments the battery system comprises an operably breachable hermetic enclosure and at least one lithium battery cell having an open-cathode architecture, the lithium cell disposed inside the hermetic enclosure and therein maintained in an open ionic circuit condition (i.e., an inactive state) throughout battery system storage. Moreover, optionally, a thermal agent may be disposed inside the hermetic enclosure for warming up one or more battery cell components, the agent typically water activated, which is to mean that it (the thermal agent) evolves heat by reacting with water.