Composite dielectric material for high-energy-density capacitors
View Patent ↗A composite dielectric material having a plurality of particle cores, each surrounded by polymer strands that are chemically bonded to the surface of the particle core. Each polymer strand includes a linker, through which the polymer strand is attached to the surface, an interfacial core-shielding (ICS) group bound to the linker, and a polymer molecule bound to the ICS group. The ICS groups are designed to inhibit electrical breakdown of the composite dielectric material by (i) deflecting or scattering free electrons away from the particle cores and/or (ii) capturing free electrons by being transformed into relatively stable radical anions. Representative examples of the particle core material, linker, ICS group, and polymer molecule are titanium dioxide, a phosphonate group, a halogenated aromatic ring, and a polystyrene molecule, respectively.
1. An apparatus, comprising:
a first electrode; and
a layer of a composite dielectric material adjacent to the first electrode, wherein:
the composite dielectric material comprises a first plurality of particle cores and a plurality of polymer strands;
a polymer strand of said plurality is chemically bonded to a corresponding particle core via a first linker and comprises an interfacial core-shielding (ICS) group and a first polymer molecule; and
the ICS group is chemically bonded to the first linker and to the first polymer molecule and comprises an aromatic moiety, wherein the aromatic moiety comprises a functional group selected from a set consisting of a metal complex of phenylpyrazole, a metal complex of dipivaloylmethanate, a derivative of chemically linked fluorene and triphenylamine, a derivative of poly(3,4-ethylenedioxythiophene), a derivative of poly(styrenesulfonate), a derivative of halogenated diphenyl ether, and a derivative of halogenated naphthalene.
2. The apparatus of claim 1 , wherein inclusion of the ICS group increases dielectric strength of the composite dielectric material.
3. The apparatus of claim 1 , wherein:
the composite dielectric material further comprises a second plurality of particle cores;
the particle cores of the first plurality comprise a first dielectric material having a first dielectric constant; and
the particle cores of the second plurality comprise a second dielectric material having a second dielectric constant smaller than the first dielectric constant.
4. The apparatus of claim 3 , wherein inclusion of the second plurality of particle cores increases dielectric strength of the composite dielectric material.
5. The apparatus of claim 1 , wherein the aromatic moiety comprises at least two aromatic rings in a non-planar spatial arrangement with respect to each other.
6. The apparatus of claim 1 , wherein the ICS group comprises an electron acceptor that, upon accepting an electron, transforms into a stable radical anion.
7. The apparatus of claim 1 , wherein:
the polymer strand is additionally chemically bonded to the corresponding particle core via a second linker; and
the ICS group is chemically bonded to the second linker.
8. The apparatus of claim 7 , wherein:
the polymer strand further comprises a second polymer molecule; and
the ICS group is chemically bonded to the second polymer molecule.
9. The apparatus of claim 1 , wherein:
the polymer strand further comprises a second polymer molecule; and
the ICS group is chemically bonded to the second polymer molecule.
10. The apparatus of claim 1 , wherein the first linker is a phosphonate group, a silyl group, or a carboxylic group.
11. The apparatus of claim 1 , wherein:
the particle cores comprise at least one of a metal niobate, a metal oxide, a metal titanate, a metal tantalite, a metal sulfide, a metal selenide, and a metal telluride;
the first electrode comprises a metal layer; and
the polymer molecule is a molecule selected from a set consisting of a polystyrene molecule, a polyethylene molecule, and a polypropylene molecule.
12. The apparatus of claim 1 , wherein the particle cores have linear dimensions that are smaller than about 0.5 micron and occupy at least about 10% of volume in the composite dielectric material.
13. The apparatus of claim 1 , further comprising a second electrode, wherein the layer of the composite dielectric material is located between the first and second electrodes.
14. The apparatus of claim 1 , wherein the first electrode and the layer of the composite dielectric material are parts of a capacitor or a field-effect transistor.
15. The apparatus of claim 1 , wherein the aromatic moiety comprises the metal complex of phenylpyrazole.
16. The apparatus of claim 15 , wherein the metal complex comprises Iridium.
17. The apparatus of claim 1 , wherein the aromatic moiety comprises the metal complex of dipivaloylmethanate.
18. The apparatus of claim 17 , wherein the metal complex comprises Iridium.
19. The apparatus of claim 1 , wherein the aromatic moiety comprises the derivative of chemically linked fluorene and triphenylamine.
20. The apparatus of claim 1 , wherein the aromatic moiety comprises the derivative of poly(3,4-ethylenedioxythiophene).
21. The apparatus of claim 1 , wherein the aromatic moiety comprises the derivative of poly(styrenesulfonate).
22. The apparatus of claim 1 , wherein the aromatic moiety comprises the derivative of halogenated diphenyl ether.
23. The apparatus of claim 1 , wherein the aromatic moiety comprises the derivative of halogenated naphthalene.
24. The apparatus of claim 1 , wherein the ICS group is adapted to perform one or more of the following:
deflect or scatter electrons away from the corresponding particle core;
inhibit collision-induced ejection of electrons from surface traps of the corresponding particle core; and
accept an electron to transform into a stable radical anion.
25. The apparatus of claim 1 , wherein, in the derivative of chemically linked fluorene and triphenylamine, a C 6 aromatic ring of the fluorene has a C—C bond to a C 6 aromatic ring of the triphenylamine.
26. A composite dielectric material, comprising:
a first plurality of particle cores; and
a plurality of polymer strands, wherein:
a polymer strand of said plurality is chemically bonded to a corresponding particle core via a first linker and comprises an interfacial core-shielding (ICS) group and a first polymer molecule; and
the ICS group is chemically bonded to the first linker and to the first polymer molecule and comprises an aromatic moiety, wherein the aromatic moiety comprises a functional group selected from a set consisting of a metal complex of phenylpyrazole, a metal complex of dipivaloylmethanate, a derivative of chemically linked fluorene and triphenylamine, a derivative of poly(3,4-ethylenedioxythiophene), a derivative of poly(styrenesulfonate), a derivative of halogenated diphenyl ether, and a derivative of halogenated naphthalene.