TITANIUM OXIDE-BASED SUPERCAPACITOR ELECTRODE MATERIAL AND METHOD OF MANUFACTURING SAME

• US 20160240328A1
• Filed: 09/29/2014
• Published: 08/18/2016
• Est. Priority Date: 09/29/2013
• Status: Active Grant

• Current Assignee: Shanghai Institute Of Ceramics, Chinese Academy Of Sciences (Chinese Academy of Sciences)
• Original Assignee: Shanghai Institute Of Ceramics, Chinese Academy Of Sciences (Chinese Academy of Sciences)
• Inventors: Huang, Fuqiang, Yang, Chongyin, Wang, Zhou
• Granted Patent: US 10,192,690 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: C01G 23/043 Titanium sub-oxides
• CPC Class Codes: C01P 2002/52 containing elements as dopants
• CPC Class Codes: C01P 2004/04 obtained by TEM, STEM, STM or AFM
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: C04B 2235/3232 Titanium oxides or titanates, e.g. rutile or anatase
• CPC Class Codes: C04B 2235/5284 Hollow fibers, e.g. nanotubes
• CPC Class Codes: C04B 35/62259 Fibres based on titanium oxide
• CPC Class Codes: C04B 35/62857 with non-oxide ceramics
• CPC Class Codes: C04B 35/62865 Nitrides
• CPC Class Codes: C04B 35/62897 Coatings characterised by their thickness
• CPC Class Codes: H01G 11/38 Carbon pastes or blends; Binders or additives therein
• CPC Class Codes: H01G 11/46 Metal oxides
• CPC Class Codes: H01G 11/86 specially adapted for electrodes carbonisation or activation of carbon for the manufacture of electrodes H01G11/34
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors

Abstract

A titanium oxide-based supercapacitor electrode material and a method of manufacturing same. A reactive substance of the titanium oxide-based supercapacitor electrode material is a conductive titanium oxide. The conductive titanium oxide is a sub-stoichiometric titanium oxide, reduced titanium dioxide, or doped reduced titanium dioxide obtained by further doping an element in reduced titanium dioxide. The titanium oxide-based supercapacitor electrode material has a carrier concentration greater than 10¹⁸ cm⁻³, and the titanium oxide-based supercapacitor electrode material has a specific capacitance 20 F/g to 1,740 F/g at a charge/discharge current of 1 A/g.

Claims

1. A titanium oxide-based supercapacitor electrode material, comprising a conductive titanium oxide as an active substance, wherein the conductive titanium oxide is selected from the group consisting of titanium sub-oxide, reduced titanium dioxide, and doped reduced titanium dioxide obtained by element doping of reduced titanium dioxide, and the titanium oxide-based supercapacitor electrode material has a density of charge carrier higher than 10¹⁸ cm⁻

3, and a specific capacitance in a range of 20 F/g˜

1,740 F/g, under a charge-discharge current of 1 A/g.

2. The titanium oxide-based supercapacitor electrode material according to claim 1, characterized in that the specific capacitance of the titanium oxide-based supercapacitor electrode material is in a range of 20 F/g˜

1,872 F/g at a charge-discharge rate of 2 mV/s, 15 F/g˜

1,130 F/g at a charge-discharge rate of 10 mV/s, 10 F/g˜

930 F/g at a charge-discharge rate of 50 mV/s, and 10 F/g˜

571 F/g at a charge-discharge rate of 100 mV/s, respectively, and has an attenuation of less than 5% after 1,000 cycles, less than 8% after 5,000 cycles, and less than 10% after 10,000 cycles, respectively.

3. The titanium oxide-based supercapacitor electrode material according to claim 1, characterized in that the titanium oxide-based electrode material can serve as a positive electrode active material, a negative electrode active material, or a synergic material in a supercapacitor, and the titanium oxide-based positive electrode material can be used to construct a symmetric supercapacitor with both of a positive electrode and a negative electrode comprising the titanium oxide-based active material.

4. The titanium oxide-based supercapacitor electrode material according to claim 1, characterized in that a whole or a surface of the titanium sub-oxide, the reduced titanium dioxide, or the doped reduced titanium dioxide has amorphous layers comprising defect structures, wherein the doping element is a metal element and/or a non-metal element, the metal element is one or more elements selected from the group consisting of vanadium, chromium, manganese, iron, cobalt, nickel, copper, niobium, molybdenum, tantalum, ruthenium, silver, platinum, tungsten, cadmium, and rhodium, and the non-metal element is one or more elements selected from the group consisting of hydrogen, nitrogen, carbon, boron, sulfur, selenium, phosphorus, fluorine, chlorine, bromine, and iodine.

5. The titanium oxide-based supercapacitor electrode material according to claim 4, characterized in that a thickness of the amorphous layer is 0.5 nm or more.

6. The titanium oxide-based supercapacitor electrode material according to claim 4, characterized in that the defect structure includes oxygen vacancies, interstitial titanium, and/or direct bonding between titanium and titanium.

7. The titanium oxide-based supercapacitor electrode material according to claim 1, characterized in that an apparent color of the titanium sub-oxide, the reduced titanium dioxide, or the doped reduced titanium dioxide ranges from yellow to green to brown to blue to gray to black depending on a conductivity.

8. A titanium oxide-based supercapacitor electrode comprising the titanium oxide-based supercapacitor electrode material according to claim 1, wherein the active substance of the titanium oxide-based supercapacitor electrode is selected from the group consisting of the titanium sub-oxide, the reduced titanium dioxide, and the doped reduced titanium dioxide obtained by element doping of the reduced titanium dioxide.

9. The titanium oxide-based supercapacitor electrode according to claim 8, characterized in that the titanium oxide-based supercapacitor electrode comprises a conductive substrate, and the titanium sub-oxide, the reduced titanium dioxide or the doped reduced titanium dioxide supported on the conductive substrate, and the conductive substrate includes a metal substrate, a carbon material substrate, and a conductive glass selected from the group consisting of FTO, ITO, AZO, ZnO:

B, ZnO;

Ga, ZnO;

In, Cd₂SnO₄, Zn₂SnO₄, TiO₂;

Nb, SrTiO₃;

Nb, CuS, CuAlO₂ and CuAlS₂.

10. The titanium oxide-based supercapacitor electrode according to claim 8, characterized in that the titanium oxide-based supercapacitor electrode is a free-standing titanium oxide-based supercapacitor electrode formed by the titanium sub-oxide, the reduced titanium dioxide, or the doped reduced titanium dioxide.

11. A method for preparing the titanium oxide-based supercapacitor electrode according to claim 8, comprising:

performing a high surface reduction treatment on titanium dioxide to obtain titanium sub-oxide or reduced titanium dioxide, or performing a high surface reduction treatment and a doping treatment on titanium dioxide to obtain doped reduced titanium dioxide;

mixing the titanium sub-oxide, the reduced titanium dioxide, or the doped reduced titanium dioxide with a solvent and an aid to obtain a slurry; and

coating the slurry on a conductive substrate followed by drying to obtain a conductive substrate-supporting titanium oxide-based supercapacitor electrode, or drying the slurry followed by milling and tabletting to obtain a free-standing titanium oxide-based supercapacitor electrode.

12. The method according to claim 11, characterized in that the aid includes a binder, and a conductive agent.

13. The method according to claim 11, characterized in that the step of performing a high surface reduction treatment on titanium dioxide to obtain titanium sub-oxide or reduced titanium dioxide comprises performing a high surface reduction treatment on titanium dioxide using a highly active metal or under a reducing atmosphere to obtain titanium sub-oxide or reduced titanium dioxide;

the step of performing a high surface reduction treatment and a doping treatment on titanium dioxide to obtain doped reduced titanium dioxide comprises;

performing a high surface reduction treatment on titanium dioxide using a highly active metal or under a reducing atmosphere followed by performing a metal and/or non-metal doping treatment;

or performing a metal and/or non-metal doping treatment on titanium dioxide followed by performing a high surface reduction treatment on the doped titanium dioxide using a highly active metal or under a reducing atmosphere, to obtain doped reduced titanium dioxide.

14. The method according to claim 12, characterized in that the conductive agent is one or more agents selected from the group consisting of acetylene black, carbon black, artificial graphite, natural graphite, flake graphite, vapor grown carbon fibers, carbon nanotubes, metal powders, and metal fibers.

15. The method according to claim 12, characterized in that the binder is one or more agents selected from the group consisting of polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, polyacrylamide, ethylene-propylene-diene copolymer resin, styrene-butadiene rubber, polybutadiene, fluorine rubber, polyethylene oxide, polyvinyl pyrrolidone, polyester resins, acrylic resins, phenolic resins, epoxy resins, polyvinyl alcohol, and hydroxypropyl cellulose.

16. The method according to claim 11, characterized in that the solvent is one or more solvents selected from the group consisting of water, alcohols, polyols, terpenes, N-methyl-2-pyrrolidone, dimethyl carbonate, diethyl carbonate, ethyl acetate, and methyl propionate.

17. The method according to claim 12, characterized in that, in the slurry, a concentration of the titanium sub-oxide, the reduced titanium dioxide, or the doped reduced titanium dioxide is 0.001˜

1 g/mL, a concentration of the binder is 1˜

50 mg/mL, and a mass ratio of the conductive agent to the reduced titanium dioxide or the doped reduced titanium dioxide is (0.05˜

10);

1.

18. The method according to claim 11, characterized in that the coating method is one or more methods selected from the group consisting of dip-coating, knife coating, spin coating, spray coating, screen printing, and suspended particles dip coating.

19. A method for preparing the titanium oxide-based supercapacitor electrode according to claim 8, comprising:

applying titanium dioxide on a conductive substrate followed by drying to obtain a conductive substrate-supporting titanium dioxide electrode, or drying a slurry containing titanium dioxide followed by milling and tabletting to obtain a free-standing titanium oxide electrode; and

performing a high surface reduction treatment and/or a doping treatment on the conductive substrate-supporting titanium oxide electrode or the free-standing titanium oxide electrode to obtain the supercapacitor electrode.

20. The method according to claim 19, characterized in that the high surface reduction treatment and/or doping treatment is:

performing a high surface reduction treatment on the conductive substrate-supporting titanium oxide electrode or the free-standing titanium oxide electrode using a highly active metal or under a reducing atmosphere;

performing a high surface reduction treatment on the conductive substrate-supporting titanium oxide electrode or the free-standing titanium oxide electrode using a highly active metal or under a reducing atmosphere followed by performing a metal and/or non-metal doping treatment;

or

performing a metal and/or non-metal doping treatment on the conductive substrate-supporting titanium oxide electrode or the free-standing titanium oxide electrode followed by performing a high surface reduction treatment using a highly active metal or under a reducing atmosphere.

21. The method according to claim 19, characterized in that the method for applying is one or more methods selected from the group consisting of dip-coating, knife coating, spin coating, spray coating, screen printing method, suspended particles dip coating, anodic electrodeposition, cathodic electrodeposition, electrophoresis, spray pyrolysis, chemical vapor deposition, and physical vapor deposition.

22. The method according to claim 20, characterized in that the high surface reduction treatment and/or the doping treatment are performed at 200˜

1,000°

C. for 2˜

12 hours.

23. The method according to claim 11, characterized in that the titanium dioxide has one or more phases selected from the group consisting of amorphous phase, anatase phase, rutile phase, and brookite phase;

and the titanium dioxide has one or more morphologies selected from the group consisting of ball, rod, strip, tube and irregular polygons.

24. Use of the titanium oxide-based supercapacitor electrode material according to claim 1, wherein the titanium oxide-based supercapacitor electrode material, serving as a synergia material, is used together with other active substances for supercapacitors to synergistically improve the capacitance and a cycle stability of the supercapacitor.