US 4,397,919 A · Explosion resistant battery cells

Abstract

An explosion resistant battery cell incorporating safety features adapted to counter the effects of the build-up of high internal pressures. The external metallic casing for the cell has a non-cylindrical cross-section which may be square, rectangular or other geometric configuration other than cylindrical to allow bulging of the outer walls which may result from internal pressure build-up. A thermal venting mechanism is provided in the nature of a low melting point metal plug inserted in the end of an associated electrolyte fill tube, the metal plug providing a hermetic seal but having a melting point considerably below the temperature at which explosion of the battery cell might occur depending on the electrolyte being used.

Claims14

Dependent claims

In an explosion resistant sealed battery cell having an electrolyte and an anode-cathode structure, the improvement comprising:

a casing formed in a non-cylindrical configuration to render it distortable in shape by internal pressure to increase its volume, said non-cylindrical casing being made of a flexible material and having such dimensions and configuration to enable such volume expanding distortion without the creation of any breaks in the casing which would vent the interior thereof to atmosphere;
and
thermally responsive means associated with said cell for hermetically sealing the cell before and during volume expansion, said thermally responsive means being operable to melt at some pre-determined temperature associated with an internal pressure in excess of that causing volume expansion, melting of said thermally responsive means venting the casing to release excessive pressure from within said casing after the pressure induced volume expansion has taken place.

Dependencies are inferred from the claim text.

Explosion resistant battery cells

Life of this patent

Explosion resistant battery cells

Life of this patent

Abstract

Claims14