# US 12,119,186 B2 · Electrolytic capacitor having an anode formed from a tantalum powder with a relatively low specific charge > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,119,186 B2 - Document ID: US12119186B2 - Status: Granted - Kind: B2 - Application number: 17/948,580 - Filed: 2022-09-20 - Published: 2023-03-02 - Granted: 2024-10-15 - Earliest claimed: 2020-04-03 - Assignees: Greatbatch Ltd. - Applicants: Greatbatch Ltd. - Inventors: Anthony C. Perez; Christina Scheuer; Barry C. Muffoletto; Jason T. Hahl - Web page: https://patentgrep.com/patent/US12119186B2 ## CPC - H01G 9/042: characterised by the material (H01G11/22 takes precedence) - H01G 9/012: specially adapted for solid capacitors - H01G 9/0425: {specially adapted for cathode} - H01G 9/048: characterised by their structure (H01G11/22 takes precedence) - H01G 9/052: Sintered electrodes - H01G 9/0525: {Powder therefor} - H01G 9/10: Sealing, e.g. of lead-in wires - H01G 9/145: Liquid electrolytic capacitors (H01G11/00 takes precedence) - H01G: CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE (selection of specified materials as dielectric H01B3/00; capacitors having potential barriers H10D1/62, H10K10/10) ## Abstract A wet tantalum electrolytic capacitor containing a cathode, fluidic working electrolyte, and anode formed from an anodically oxidized sintered porous tantalum pellet is described. The pellet is formed from a pressed tantalum powder. The tantalum powder is formed by reacting a tantalum oxide compound, for example, tantalum pentoxide, with a reducing agent that contains a metal having an oxidation state of 2 or more, for example, magnesium. The resulting tantalum powder is nodular or angular and has a specific charge that ranges from about 9,000 μF*V/g to about 11,000 μF*V/g. Using this powder, wet tantalum electrolytic capacitors have breakdown voltages that ranges from about 340 volts to about 450 volts. This makes the electrolytic capacitors ideal for use in an implantable medical device. ## Claims ### Claim 1 An electrolytic capacitor for use in an implantable medical device, the electrolytic capacitor comprising: a) a casing; b) at least one tantalum anode housed in the casing, the at least one tantalum anode comprising an anodically oxidized pellet formed from a pressed and sintered tantalum powder of agglomerated tantalum particles, wherein the at least one tantalum anode is characterized as having been formed to a voltage that ranges from 310 volts to about 430 volts, and wherein the tantalum powder has: i) tantalum particles with an aspect ratio of about 1 to about 2; ii) tantalum particles with sinter necks having a thickness that ranges from about 200 nanometers to about 1,100 nanometers; iii) a specific charge that ranges from about 9,000 μF*V/g to about 11,000 μF*V/g, and iv) wherein the at least one tantalum anode has a breakdown voltage that ranges from about 340 volts to about 450 volts; c) a lead wire that extends from the at least one tantalum anode to outside the casing, the lead wire being electrically isolated from the casing; d) a cathode comprising a cathode material coated on at least one inner surface of the casing or coated on a conductive substrate electrically connected to the casing, the cathode material facing the at least one tantalum anode; e) a separator positioned between the at least one tantalum anode and the cathode; and f) a fluidic working electrolyte contained in the casing in contact with the at least one tantalum anode and the cathode. ### Claim 2 (depends on 1) The capacitor of claim 1, wherein the at least one tantalum anode has a breakdown voltage that ranges from about 360 volts to about 420 volts. ### Claim 3 (depends on 1) The electrolytic capacitor of claim 1, wherein the sinter necks have a thickness that ranges from about 500 nanometers to about 800 nanometers. ### Claim 4 (depends on 1) The electrolytic capacitor of claim 1, wherein the tantalum powder has an energy density that ranges from about 2.0 J/cm3 to about 11.0 J/cm3. ### Claim 5 (depends on 1) The electrolytic capacitor of claim 1, wherein in addition to the at least one tantalum anode, the casing houses at least a second tantalum anode, and wherein the cathode material coated on the conductive substrate is positioned between the at least one tantalum anode and at least the second tantalum anode. ### Claim 6 (depends on 1) The electrolytic capacitor of claim 1, wherein the tantalum powder is formed by reacting an oxide of tantalum with a reducing agent that contains magnesium, strontium, barium, cesium, calcium, aluminum, and a combination thereof. ### Claim 7 (depends on 1) The electrolytic capacitor of claim 1, wherein the tantalum powder has a specific surface area that ranges from about 0.25 m2/g to about 0.6 m2/g. ### Claim 8 (depends on 1) The electrolytic capacitor of claim 1, wherein the tantalum powder has no more than about 50 ppm of an alkali metal. ### Claim 9 (depends on 1) The electrolytic capacitor of claim 1, wherein the tantalum powder is nodular or angular. ### Claim 10 (depends on 1) The electrolytic capacitor of claim 1, wherein the at least one tantalum anode is comprised of primary particles of tantalum have a median size that ranges from about 10 nanometers to about 500 nanometers. ### Claim 11 (depends on 1) The electrolytic capacitor of claim 1, wherein the at least one tantalum anode has a thickness that ranges from about 0.1 millimeters to about 3.5 millimeters, and a width that ranges from about 2 to about 25 millimeters. ### Claim 12 (depends on 1) The electrolytic capacitor of claim 1, wherein the casing is selected from titanium, tantalum, nickel, molybdenum, niobium, cobalt, stainless steel, tungsten, platinum, palladium, silver, copper, chromium, vanadium, aluminum, zirconium, hafnium, zinc, iron, and mixtures and alloys thereof. ### Claim 13 (depends on 1) The electrolytic capacitor of claim 1, wherein the cathode material is selected from an anodized-etched conductive material, a sintered active material with or without oxide contacted thereto, a double layer capacitive material, a finely divided carbonaceous material, graphite, carbon, platinum black, a redox, pseudocapacitive, an under potential material, an electroactive conducting polymer, polyaniline, polypyrrole, polythiophene, polyacetylene. ### Claim 14 (depends on 1) The electrolytic capacitor of claim 1, wherein the cathode material is selected from an oxide of a metal, a nitride of the metal, a carbon nitride of the metal, and a carbide of the metal, the metal being selected from the group of ruthenium, cobalt, manganese, molybdenum, tungsten, tantalum, iron, niobium, iridium, titanium, zirconium, hafnium, rhodium, vanadium, osmium, palladium, platinum, nickel, and lead. ### Claim 15 (depends on 1) The electrolytic capacitor of claim 1, wherein the working electrolyte has a pH that ranges from about 5.0 to about 7.5. ### Claim 16 (depends on 1) The electrolytic capacitor of claim 1, wherein the casing comprises a first casing member having a face wall meeting a surrounding sidewall that extends to an edge, and a second plate-shaped casing member that is sealed to the edge of the surrounding sidewall of the first casing member. ### Claim 17 (depends on 1) The electrolytic capacitor of claim 1, wherein the casing comprises mating clamshell-type casing members that are hermetically sealed together. ### Claim 18 (depends on 1) An implantable medical device comprising the electrolytic capacitor of claim 1. ### Claim 19 An electrolytic capacitor for use in an implantable medical device, the electrolytic capacitor comprising: a) a casing; b) at least one tantalum anode housed in the casing, the at least one tantalum anode comprising an anodically oxidized pellet formed from a pressed and sintered tantalum powder of agglomerated tantalum particles, wherein the at least one tantalum anode is characterized as having been formed to a voltage that ranges from about 310 volts to about 430 volts, and wherein the tantalum powder has: i) tantalum particles with an aspect ratio of about 1 to about 2; ii) tantalum particles with sinter necks having a thickness that ranges from about 500 nanometers to about 800 nanometers; iii) a specific charge that ranges from about 9,000 μF*V/g to about 11,000 μF*V/g, iv) wherein the at least one tantalum anode has a breakdown voltage that ranges from about 340 volts to about 450 volts; c) a lead wire that extends from the at least one tantalum anode to outside the casing, the lead wire being electrically isolated from the casing; d) a cathode comprising ruthenium oxide coated on at least one inner surface of the casing or coated on a conductive substrate electrically connected to the casing, the ruthenium oxide facing the at least one tantalum anode; e) a separator positioned between the at least one tantalum anode and the cathode; and f) a fluidic working electrolyte contained in the casing in contact with the at least one tantalum anode and the cathode. ### Claim 20 (depends on 19) The electrolytic capacitor of claim 19, wherein the at least one tantalum anode has a breakdown voltage that ranges from about 360 volts to about 420 volts.