Dielectric material containing dipolar molecules

• US 5,390,073 A
• Filed: 01/11/1993
• Issued: 02/14/1995
• Est. Priority Date: 01/11/1993
• Status: Expired due to Fees

• Current Assignee: Maxwell Electronic Components Group Incorporated (Tesla Inc.)
• Original Assignee: Maxwell Laboratories, Inc. (UCAP Power, Inc.)
• Inventors: McMillan, William G.
• Primary Examiner(s): Paschall, Mark H.
• Assistant Examiner(s): Mills, Gregory L.
• Application Number:
  US08/002,916
• Time in Patent Office: 764 Days
• Field of Search: 361/314, 361/315, 361/319, 361/323, 361/327, 252/570, 252/575, 252/577, 524/236
• US Class Current: 361/327
• CPC Class Codes: H01B 3/44 vinyl resins; acrylic resins silicones H01B3/46
• CPC Class Codes: H01G 4/18 of synthetic material, e.g. derivatives of cellulose H01G4/16 takes precedence
• CPC Class Codes: H01G 4/221 characterised by the composition of the impregnant
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

Dielectric materials having a high dipole moment density are provided. The high dipole moment density is achieved by the use of a substituted α-amino acid, such as N-trimethyl glycine and related homologues having nonpolar sidechain groups, with three alkyl substitutions on the nitrogen of the α-amino group. These molecules have a high dipole moment and small volume, allowing rapid rotation around the α-amino, carboxyl dipole. N-trimethyl glycine alone or in combination with one or more homologues is preferably provided as a solute in a liquid dielectric solution. Alternatively, these molecules are provided as substituents on a linear polymer.

Claims

1. A capacitor including at least two electrodes separated by a dielectric material, wherein said dielectric material comprises at least one N-trialkyl substituted α

-amino acid of the formula;

##STR2## wherein R₁ is chosen from the group consisting of hydrogen and a non-polar group; and

R₂, R₃, and R₄ are alkyl groups having no more than three carbon atoms.

2. The capacitor according to claim 1 wherein said alkyl groups R₂, R₃, and R₄ are methyl groups.

3. The capacitor according to claim 2 wherein said trialkyl substituted material includes N-trimethyl glycine.

4. The capacitor according to claim 3 wherein said dielectric material includes a solution wherein such N-trimethyl glycine is present as a solute.

5. The capacitor according to claim 4 wherein said solution includes a polar solvent selected from the group consisting of methyl alcohol, ethyl alcohol, and ethyl ether.

6. The capacitor according to claim 3 wherein said dielectric material includes a polymer component having N-trimethyl glycine as a substituent thereupon.

7. The capacitor according to claim 6 wherein said N-trimethyl glycine is attached to said polymer by removal of a hydrogen atom from one of the methyl groups, R₂, R₃, or R₄.

8. The capacitor of claim 7 wherein said polymer has a linear backbone chain.

9. An electrical capacitor comprising a housing, a capacitance section within said housing, said section having at least one pair of spaced-apart electrodes and a dielectric material between said electrodes, wherein said dielectric material comprises a polymer component having N-trimethyl glycine as a substituent which is attached to said polymer component through one of the methyl groups of said N-trimethyl glycine.

10. The capacitor of claim 9 wherein said dielectric material comprises a polymer of methyl methacrylate.

11. An electric capacitor of small size and compact energy-density, capable of delivering large amounts of power, which capacitor comprises a housing, a capacitance section within said housing, said section having at least one pair of spaced-apart electrodes and a dielectric material between said electrodes, wherein said dielectric material comprises a solution including N-trimethyl glycine.

12. The capacitor of claim 11 wherein the dielectric is in a liquid solution consisting of a polar solvent selected from the group including of methyl alcohol, ethyl alcohol, and ethyl ester.