Battery

Abstract

A battery includes a battery can housing an cell that supplies electrical energy at terminals of the cell by an electro-chemical reaction with oxygen, the can including, a first member having at least one hole that is exposed to air; and a second member. The battery also includes a mechanism coupled to one of the first and second members to move the one of the first and second members such that when current is drawn from the battery, the opening in the member allows air to pass into the battery, and to move the one of the first and second members such that when current is not drawn from the battery, the opening in the member is not in registration to inhibit air to pass into the battery. The battery also includes a circuit to control the mechanism. In one embodiment the circuit monitors levels of O 2 in a air plenum that surrounds the cell. The circuit to monitor levels of O 2 in the air plenum includes a florescent detector/sensor that senses and responds to changes in O 2 in the plenum by using the “quenching effect” of oxygen on a fluorescent material

1 .- 25 . (canceled) 
   
   
       26 . An air valve for a battery comprises:
 a first cylindrical member having at least one hole in sidewalls of the member, the hole exposed to air;   a ribbon of a shape memory alloy material, the ribbon disposed over the at least one hole in the first cylinder; and   a circuit coupled to ribbon in order to move the ribbon such that when current is consumed from the battery, the opening in the cylindrical member is uncovered by the ribbon to allow air to pass through the valve, and to move the ribbon such that when current is not drawn from the battery, the opening in the cylindrical member is covered by the ribbon to inhibit air from passing through the valve.   
   
   
       27 . The battery of  claim 26 , wherein the cylindrical member has a plurality of openings arranged in a column along the length of the cylindrical member and the ribbon covers or uncovers the plurality of openings. 
   
   
       28 . The battery of  claim 26 , wherein the cylindrical member has a plurality of openings, arranged in a plurality of columns of openings along the length of the cylindrical member and further comprises:
 a plurality of ribbons including the ribbon, the plurality of ribbons covering or uncovering the plurality of openings arranged in the plurality of columns.   
   
   
       29 . A battery comprises:
 a cell;   an air valve to control the level of air in the cell;   an air plenum surrounding the cell;   a circuit to monitor levels of O 2  in the air plenum.   
   
   
       30 . The battery of  claim 29  wherein the circuit to monitor levels of O 2  in the air plenum comprises:
 a florescent detector/sensor that senses and responds to changes in O 2  in the plenum by using the “quenching effect” of oxygen on a fluorescent material.   
   
   
       31 . The battery of  claim 30  wherein fluorescent material absorb light in a certain wavelength range and emit light over a different range of wavelengths to give an indication of the level of O 2  in the plenum. 
   
   
       32 . The battery of  claim 30  wherein the fluorescent sensor comprises a permeable polymer matrix that is doped with a dopant to produce fluorescence in the presence of oxygen. 
   
   
       33 . The battery of  claim 30  wherein the fluorescent sensor further comprises:
 a LED emitter to illuminate the matrix material in the excitation spectrum; and   a photodiode receiver to detect a phase shift in light spectrum and hence change of the oxygen level.   
   
   
       34 . The battery of  claim 30 , further comprises:
 a signal processor coupled to the fluorescent sensor, the processor executing an empirically determined algorithm to monitor the level of oxygen in the cell according to the current being drawn from the cell in order to regulate the air valve and hence air flow into the cell.   
   
   
       35 . The battery of  claim 34 , wherein the signal processor outputs a signal that can be used to switched open/close the air valve and thus modulate the supply of air to the cell dependant current drawn from the cell. 
   
   
       36 . The battery of  claim 34 , wherein the signal processor executes an algorithm to operate the air mover in direct relationship to the oxygen consumed by the cell, and output current/voltage levels produced from the cell. 
   
   
       37 . The battery of  claim 31 , wherein the fluorescent O 2  sensor is comprised of Pt (TfPP) (platinium tetraphenylporphryrin), Pt OEP (platinium octaethylporphryrin), or Ru(BaThO) 3  (ruthenimum complexes) immobilized in an oxygen permeable matrix. 
   
   
       38 . The battery of  claim 29 , wherein the cell is a fuel cell. 
   
   
       39 . The battery of  claim 29 , wherein the cell is a direct methanol fuel cell. 
   
   
       40 . The battery of  claim 29 , wherein the cell is a metal-air cell. 
   
   
       41 . The battery of  claim 29 , wherein the cell is a zinc-air cell. 
   
   
       42 . The battery of  claim 29 , wherein the fuel cell is a direct methanol cell and the air valve is used to isolate in an anode chamber of the fuel cell from crossing over to a cathode when the anode catalyst is electrically disconnected from a load preventing evaporation of the methanol in the cell. 
   
   
       43 .- 55 . (canceled) 
   
   
       56 . A method of operating a battery, the method comprises:
 controlling a quantity of air that enters an metal-air battery by:   monitoring levels of O 2  in the battery by sensing and responding to changes in O 2  in battery and moving a first cylindrical member having at least one hole that is exposed to air relative to a second member having a least one hole according to monitored levels of O 2  in the battery.   
   
   
       57 . The method of  claim 56 , wherein monitoring uses a fluorescent sensor comprising a permeable polymer matrix that is doped with a dopant to produce fluorescence in the presence of oxygen, and the method further comprises:
 monitoring the level of fluorescence.   
   
   
       58 . The method of  claim 57 , further comprising:
 outputting a signal to switched open/close an air valve to modulate the supply of air to the cell dependant upon the current drawn from the cell.