Feedthrough insulator cap for medical device battery

Abstract

A battery configured to support a relatively high rate of energy discharge relative to its capacity for energy intensive therapy delivery. The battery includes a feedthrough insulator cap disposed within the interior of the battery on at least a portion of a ferrule, at least a portion of an insulator, and at least a portion of a pin, which define a feedthrough extending through an enclosure of the battery; a first electrode disposed within the enclosure and electrically coupled to the pin; a second electrode disposed within the enclosure and separated a distance from the first electrode; and an electrolyte disposed between the first electrode and the second electrode. During operation of the battery, the feedthrough insulator cap reduces dendrite formation on at least a portion of the ferrule, the pin, or both.

What is claimed is: 
     
         1 . A battery comprising:
 an enclosure defining an interior of the battery and a feedthrough aperture open to an exterior of the battery;   a ferrule extending through the feedthrough aperture and coupled to the enclosure;   an insulator extending through the ferrule to the exterior of the battery;   a pin extending through the insulator from the interior of the battery to the exterior of the battery, wherein the insulator electrically insulates the pin from the ferrule;   a feedthrough insulator cap disposed within the interior of the battery on at least a portion of the ferrule, at least a portion of the insulator, and at least a portion of the pin;   a first electrode disposed within the enclosure and electrically coupled to the pin;   a second electrode disposed within the enclosure and separated a distance from the first electrode; and   an electrolyte disposed between the first electrode and the second electrode.   
     
     
         2 . The battery of  claim 1 , wherein the feedthrough insulator cap, during operation of the battery, prevents formation of dendrites on at least the portion of the ferrule or the portion of the pin. 
     
     
         3 . The battery of  claim 1 , wherein the feedthrough insulator cap comprises:
 a brim comprising an annular disk extending substantially within a plane, the brim having an interior edge and an exterior edge; and   a crown integrally formed with the interior edge of the brim, wherein the crown extends above the plane of the brim in a first direction.   
     
     
         4 . The battery of  claim 3 , wherein, prior to a reflow process, the crown extends above the plane of the brim at an angle within a range from about 90-degrees to about 135-degrees relative to the plane. 
     
     
         5 . The battery of  claim 3 , wherein a height of the crown above the brim is within a range between about 0.1 millimeters (mm) to about 5.0 mm. 
     
     
         6 . The battery of  claim 3 , wherein the brim comprises a deflection including the exterior edge of the brim, the deflection extending below the plane of the disk in a second direction. 
     
     
         7 . The battery of  claim 6 , wherein, prior to a reflow process, the deflection extends below the plane of the disk at an angle within a range from about 90-degrees to about 135-degrees relative to the plane. 
     
     
         8 . The battery of  claim 6 , wherein a height of the deflection below the plane of the disk is within a range between about 0.1 millimeters (mm) to about 3.0 mm. 
     
     
         9 . The battery of  claim 1 , wherein the ferrule comprises a cylindrical annulus having a radially exterior surface, a radially interior surface, and an interior annulus disposed within the enclosure, wherein the radially exterior surface is coupled to the feedthrough aperture, and wherein the feedthrough insulator cap is disposed over the interior annulus of the ferrule and at least a portion of the radially exterior surface. 
     
     
         10 . The battery of  claim 1 , wherein the battery is a high-rate primary lithium metal battery. 
     
     
         11 . A medical device comprising:
 an outer housing; and   a high-rate primary battery within the outer housing, wherein the high-rate primary battery is configured to supply power to one or more electronic components of the medical device, and wherein the high-rate primary battery comprises:
 an enclosure defining an interior of the battery and a feedthrough aperture open to an exterior of the battery; 
 a ferrule extending through the feedthrough aperture and coupled to the enclosure; 
 an insulator extending through the ferrule to the exterior of the battery; 
 a pin extending through the insulator from the interior of the battery to the exterior of the battery, wherein the insulator electrically insulates the pin from the ferrule; 
 a feedthrough insulator cap disposed within the interior of the battery on at least a portion of the ferrule, at least a portion of the insulator, and at least a portion of an interior segment of the pin; 
 a first electrode disposed within the enclosure and electrically coupled to the pin; 
 a second electrode disposed within the enclosure and separated a distance from the first electrode; and 
 an electrolyte disposed between the first electrode and the second electrode. 
   
     
     
         12 . The medical device of  claim 11 , wherein the feedthrough insulator cap, during operation of the battery, prevents formation of dendrites on at least a portion of the ferrule or the pin. 
     
     
         13 . The medical device of  claim 11 , wherein the feedthrough insulator cap comprises:
 a brim comprising an annular disk extending substantially within a plane, the brim having an interior edge and an exterior edge; and   a crown integrally formed with the interior edge of the brim, wherein the crown extends above the plane of the brim in a first direction.   
     
     
         14 . The medical device of  claim 13 , wherein, prior to a reflow process, the crown extends above the plane of the brim at an angle within a range from about 90-degrees to about 135-degrees relative to the plane. 
     
     
         15 . The medical device of  claim 13 , wherein a height of the crown above the brim is within a range between about 0.1 millimeters (mm) to about 5.0 mm. 
     
     
         16 . The medical device of  claims 13 , wherein the brim comprises a deflection including the exterior edge of the brim, the deflection extending below the plane of the disk in a second direction. 
     
     
         17 . The medical device of  claim 16 , wherein, prior to a reflow process, the deflection extends below the plane of the disk at an angle within a range from about 90-degrees to about 135-degrees relative to the plane. 
     
     
         18 . The medical device of  claim 16 , wherein a height of the deflection below the plane of the disk is within a range between about 0.1 millimeters (mm) to about 3.0 mm. 
     
     
         19 . The medical device of  claim 11 , wherein the ferrule comprises a cylindrical annulus having a radially exterior surface, a radially interior surface, and an interior annulus disposed within the enclosure, wherein the radially exterior surface is coupled to the feedthrough aperture, and wherein the feedthrough insulator cap is disposed on at least a portion of the interior annulus of the ferrule, the insulator, and at least a portion of the pin. 
     
     
         20 . The medical device of  claim 11 , wherein the high-rate primary battery is a high-rate primary lithium metal battery. 
     
     
         21 . The medical device of  claim 11 , wherein the medical device is configured to be implantable in a body of a patient. 
     
     
         22 . The medical device of  claim 11 , wherein the medical device is configured to provide cardiac rhythm management therapy to a heart of a patient. 
     
     
         23 . A method of assembling a battery comprising:
 positioning a feedthrough insulator cap on a feedthrough of the battery, wherein the battery comprises:
 an enclosure defining the interior of the battery and a feedthrough aperture open to an exterior of the battery, the feedthrough comprising:
 a ferrule extending through the feedthrough aperture and coupled to the enclosure; 
 an insulator extending through the ferrule to the exterior of the battery; and 
 a pin extends through the insulator from the interior of the battery to the exterior of the battery, and wherein the insulator electrically insulates the pin from the ferrule; 
 
 a first electrode disposed within the enclosure and electrically coupled to the pin; 
 a second electrode disposed within the enclosure and separated a distance from the first electrode; and 
 an electrolyte disposed between the first electrode and the second electrode; and 
   heating the feedthrough insulator cap to reflow a material of the feedthrough insulator cap onto at least a portion of a ferrule, at least a portion of an insulator, and at least a portion of an interior segment of a pin.   
     
     
         24 . The method of  claim 23 , wherein the feedthrough insulator cap comprises:
 a brim comprising an annular disk extending substantially within a plane, the brim having an interior edge and an exterior edge; and   a crown integrally formed with the interior edge of the brim, wherein the crown extends above the plane of the brim in a first direction.   
     
     
         25 . The method of  claim 24 , wherein the ferrule comprises a cylindrical annulus having a radially exterior surface, a radially interior surface, and an interior annulus disposed within the enclosure, wherein the radially exterior surface is coupled to the feedthrough aperture, and wherein heating the feedthrough insulator cap causes the brim to extend over a lip of a radially exterior surface of the ferrule. 
     
     
         26 . The method of  claim 24 , wherein the pin comprises an interior segment extending from the insulator to the first electrode, wherein heating the feedthrough insulator cap causes the crown to reflow on to at least a portion of the interior segment of the pin. 
     
     
         27 . The method of  claim 23 , further comprising electrically coupling the first electrode and the second electrode to an implantable medical device. 
     
     
         28 . The method of  claim 23 , further comprising implanting the high-rate primary battery in a body of a patient. 
     
     
         29 . The method of  claim 23 , wherein positioning the feedthrough insulator cap on the feedthrough comprises injection molding the feedthrough insulator cap directly onto the feedthrough.