Electrochemical cell with flat casing and vent

Abstract

An electrochemical cell generating hydrogen gas upon discharge, wherein the cell has an outer casing, a vent aperture passing through a wall of the casing, and a rupturable membrane covering the vent aperture. The outer casing preferably has a flat wall running along the cell's length and a vent aperture passing through the flat wall. The cell may typically be an alkaline cell in the shape of a cuboid. The rupturable membrane may be secured by a ring facing the inside surface of the flat wall of the casing in a position adjacent the vent aperture. The rupturable membrane is preferably of polysulfone. The membrane allows hydrogen gas to permeate therethrough to the environment and is rupturable if hydrogen gas within the cell interior builds up rapidly to a threshold pressure level. Optionally, a pointed puncture member extends into the vent aperture to assist membrane rupture.

Description

technical field

[0001] The invention relates to an electrochemical cell having a hole in the wall of the housing and a rupturable membrane covering the hole. The invention relates to a flat battery, which may be an alkaline battery, having an anode comprising zinc, a cathode comprising manganese dioxide and an electrolyte comprising liquid potassium hydroxide. Background technique

[0002] Common alkaline cells (alkaline electrochemical cells) have an anode comprising zinc and a cathode comprising manganese dioxide. Batteries are generally formed with elongated cylindrical casings. A new battery has an open circuit (EMF) voltage of approximately 1.5 volts, with an average operating voltage of 1.0 to 1.2 volts at half service life (100 to 300 mA). A cylindrical housing is initially formed with an open end and an opposite closed end. When the battery contents are fed, the end cap with the insulating plug is inserted into the open end of the case and forms the negative pole....

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