Patent ID: 8304108

Claim:
A battery assembly, comprising: a battery, said battery comprising: a pre-formed cell case having an exterior sidewall surface, a first end portion and a second end portion, wherein said first end portion is comprised of a cell case bottom, and wherein said second end portion is comprised of a cap assembly retention lip and a central open portion; an electrode assembly contained within said pre-formed cell case, wherein a first electrode of said electrode assembly is electrically connected to said pre-formed cell case; and a cap assembly mounted to said pre-formed cell case, said cap assembly closing said central open portion of said second end portion, wherein said cap assembly further comprises a battery terminal electrically isolated from said pre-formed cell case and electrically connected to a second electrode of said electrode assembly; and a pre-formed sleeve positioned around and in contact with said pre-formed cell case, wherein said pre-formed sleeve is formed separately from said pre-formed cell case, wherein an interior surface of said pre-formed sleeve is proximate to said exterior sidewall surface of said pre-formed cell case, wherein a case contact region of said exterior sidewall surface of said pre-formed cell case remains uncovered by said pre-formed sleeve, wherein said case contact region is proximate to an end surface of said pre-formed cell case, wherein said pre-formed sleeve is comprised of a high yield strength material, wherein said pre-formed sleeve inhibits the escape of hot, pressurized gas from within said battery through said exterior sidewall surface of said cell case during a thermal runaway event, and wherein said pre-formed sleeve directs the flow of said hot, pressurized gas towards said first end portion or said second end portion.