# US 7,268,996 B1 · Electrolyte for very high voltage electrolytic capacitors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,268,996 B1 - Document ID: US7268996B1 - Status: Granted - Kind: B1 - Application number: 10/340,051 - Filed: 2003-01-10 - Granted: 2007-09-11 - Earliest claimed: 2003-01-10 - Assignees: Pacesetter, Inc. - Inventors: Roland Francis Dapo; Christopher Feger - Web page: https://patentgrep.com/patent/US7268996B1 ## CPC - H01G 9/035: Liquid electrolytes, e.g. impregnating materials (H01G11/54 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 The present invention is directed to an electrolyte for use in very high voltage electrolytic capacitors and to an electrolytic capacitor impregnated with the electrolyte of the present invention for use in an implantable cardioverter defibrillator (ICD). The electrolyte according to the present invention is composed of a mixture of an alkoxy-substituted alcohol, such as 2-methoxyethanol, 2-ethoxyethanol, or 2-butoxyethanol, and a long chain dicarboxylic acid, where the acid functional groups are separated by 34 carbons (referred to as “dimer acid”) or 54 carbons (referred to as “trimer acid”). The solution is then neutralized with ammonium hydroxide or other amine, such as ammonia, dimethylamine, trimethylamine, diethylamine, triethylamine, ethanolamine, diethanolamine, triethanolamine, diisopropylethylamine and N-methylimidazole. Additional cosolvents, such as ethylene glycol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, di(ethylene glycol), tri(ethylene glycol), tetra(ethylene glycol), propyl alcohol, isopropyl alcohol, n-butanol, and di(ethylene glycol) butyl ether, may be added. Also, a cathode depolarizer, or degassing agent, from the group of nitro-substituted aromatic compounds (nitroaromatics) can be added to reduce the amount of gas produced during capacitor life. ## Claims ### Claim 1 An electrolyte for use in very high voltage electrolytic capacitors, comprising: an alkoxy-substituted alcohol; a dicarboxylic acid where the acid functional groups are separated by at least 34 carbons; and an amine. ### Claim 2 (depends on 1) An electrolyte according to claim 1, wherein said electrolyte has a breakdown voltage of greater than about 750 V. ### Claim 3 (depends on 1) An electrolyte according to claim 1, wherein said alkoxy-substitute alcohol is 2-methoxyethanol. ### Claim 4 (depends on 1) An electrolyte according to claim 1, wherein said alkoxy-substitute alcohol is 2-ethoxyethanol. ### Claim 5 (depends on 1) An electrolyte according to claim 1, wherein said alkoxy-substitute alcohol is 2-butoxyethanol. ### Claim 6 (depends on 1) An electrolyte according to claim 1, wherein said dicarboxylic acid is dimer acid and the acid functional groups are separated by 34 carbons. ### Claim 7 (depends on 1) An electrolyte according to claim 1, wherein said dicarboxylic acid is trimer acid and the acid functional groups are separated by 54 carbons. ### Claim 8 (depends on 1) An electrolyte according to claim 1, wherein said amine is selected from the group consisting of ammonia, dimethylamine, trimethylamine, diethylamine, triethylamine, ethanolamine, diethanolamine, triethanolamine, diisopropylethylamine and N-methylimidazole. ### Claim 9 (depends on 1) An electrolyte according to claim 1, wherein said amine is ammonium hydroxide. ### Claim 10 (depends on 1) An electrolyte according to claim 1, comprising about 30.0% to about 80.0% by weight of an alkoxy-substituted alcohol, about 5.0% to about 40.0% by weight of a dicarboxylic acid where the acid functional groups are separated by at least 34 carbons, and not more than about 6.0% by weight of an amine. ### Claim 11 (depends on 1) An electrolyte according to claim 1, comprising about 35.0% to about 75.0% by weight of an alkoxy-substituted alcohol, about 20.0% to about 35% by weight of a dicarboxylic acid where the acid functional groups are separated by at least 34 carbons and about 2.0% to about 4.0% by weight of an amine. ### Claim 12 (depends on 1) An electrolyte according to claim 1, further comprising a cosolvent. ### Claim 13 (depends on 12) An electrolyte according to claim 12, wherein said cosolvent is selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, di(ethylene glycol), tri(ethylene glycol), tetra(ethylene glycol), propyl alcohol, isopropyl alcohol, n-butanol, and di(ethylene glycol) butyl ether. ### Claim 14 (depends on 12) An electrolyte according to claim 12, comprising about 30.0% to about 80.0% by weight of an alkoxy-substituted alcohol, not more than about 50.0% by weight of a cosolvent, about 5.0% to about 40.0% by weight of a dicarboxylic acid where the acid functional groups are separated by at least 34 carbons, and about not more than about 6.0% by weight of an amine. ### Claim 15 (depends on 12) An electrolyte according to claim 12, comprising about 35.0% to about 75.0% by weight of an alkoxy-substituted alcohol, about 5.0% to about 40.0% by weight of a cosolvent, about 20.0% to about 35% by weight of a dicarboxylic acid where the acid functional groups are separated by at least 34 carbons and about 2.0% to about 4.0% by weight of an amine. ### Claim 16 (depends on 1) An electrolyte according to claim 1, further comprising a cathode depolarizer. ### Claim 17 (depends on 16) An electrolyte according to claim 16, wherein said cathode depolarizer is a nitro-substitute aromatic compound. ### Claim 18 (depends on 17) An electrolyte according to claim 17, wherein said nitro-substituted aromatic compound is selected from the group consisting of: nitrobenzene, nitrotoluene, nitrophenol, nitroacetophenone, nitrobenzyl alcohol and nitroanisole. ### Claim 19 (depends on 1) An electrolyte according to claim 1, further comprising water. ### Claim 20 (depends on 19) An electrolyte according to claim 19, comprising not more than about 8.0% by weight water. ### Claim 21 An electrolyte for use in very high voltage electrolytic capacitors, comprising 2-methoxyethanol, di(ethylene glycol), dimer acid and ammonium hydroxide. ### Claim 22 (depends on 21) An electrolyte according to claim 21, comprising about 30.0% to about 80.0% by weight 2-methoxyethanol, not more than about 50.0% by weight di(ethylene glycol), about 5.0% to about 40.0% by weight dimer acid, and not more than about 6.0% by weight ammonium hydroxide. ### Claim 23 (depends on 21) An electrolyte according to claim 21, comprising about 35.0% to about 75.0% by weight 2-methoxyethanol, about 5.0% to about 40.0% by weight di(ethylene glycol), about 20.0% to about 35% by weight dimer acid and about 2.0% to about 4.0% by weight ammonium hydroxide. ### Claim 24 (depends on 21) An electrolyte according to claim 21, comprising 50.0% by weight 2-methoxyethanol, 23.0% by weight di(ethylene glycol), 25.0% by weight dimer acid and 2.0% by weight ammonium hydroxide. ### Claim 25 (depends on 1) An electrolytic capacitor impregnated with the electrolyte of claim 1. ### Claim 26 (depends on 21) An electrolytic capacitor impregnated with the electrolyte of claim 21. ### Claim 27 (depends on 1) An implantable cardioverter defibrillator comprising an electrolytic capacitor impregnated with the electrolyte of claim 1. ### Claim 28 (depends on 21) An implantable cardioverter defibrillator comprising an electrolytic capacitor impregnated with the electrolyte of claim 21.