Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
  • H01G11/54—Electrolytes
  • H01G11/56—Solid electrolytes, e.g. gels; Additives therein
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
  • H01G11/04—Hybrid capacitors
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
  • H01G11/22—Electrodes
  • H01G11/26—Electrodes characterised by their structure, e.g. multi-layered, porosity or surface features
  • H01G11/28—Electrodes characterised by their structure, e.g. multi-layered, porosity or surface features arranged or disposed on a current collector; Layers or phases between electrodes and current collectors, e.g. adhesives
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
  • H01G11/22—Electrodes
  • H01G11/30—Electrodes characterised by their material
  • H01G11/46—Metal oxides
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
  • H01G11/66—Current collectors
  • H01G11/68—Current collectors characterised by their material
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
  • H01G11/02—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof using combined reduction-oxidation reactions, e.g. redox arrangement or solion
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
  • H01G11/66—Current collectors
  • H01G11/70—Current collectors characterised by their structure
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
  • Y02E60/13—Energy storage using capacitors

Definitions

• the present disclosure is related to hybrid capacitors, specifically to Pb0 2 /Activated Carbon hybrid ultracapacitors with an inorganic thixotropic-gelled-polymeric-electrolyte.
• the hybrid ultracapacitor of the present disclosure is simple to assemble, bereft of impurities and can be charged / discharged -rapidly- with high faradaic efficiency.
• Supercapacitors are being projected as devices that could enable major advances in energy storage.
• Supercapacitors are governed by the same physics as conventional capacitors, but utilize high-surface-area electrodes and thinner dielectrics to achieve greater capacitances, allowing energy densities greater than those of conventional capacitors and power densities greater than those of batteries.
• Supercapacitors can be divided into three general classes, namely, electrical-double-layer capacitors, pseudocapacitors and hybrid capacitors. Each class is characterized by its unique mechanism for charge storage, namely faradaic, non-faradaic, and the combination of the two.
• Faradaic processes such as oxidation-reduction reactions, involve the transfer of charge between electrode and electrolyte as in a battery electrode, while a non-faradaic mechanism does not use a chemical mechanism - rather, charges are distributed on surfaces by physical processes that do not involve the making or braking of chemical bonds similar to "the electrical double-layer".
• a hybrid supercapacitor combines a battery electrode where the energy is stored in chemical form, and an electrical- double-layer electrode where the energy is stored in physical form.
• a Pb0 2 /Activated Carbon supercapacitor comprises a positive plate akin to a lead acid cell and a high surface-area activated carbon electrode as negative plate. The charge-discharge reactions at the positive and negative plates of such a hybrid supercapacitors are as follows.
• (+) plate PbS0 4 +2H 2 O ⁇ Pb0 2 + H 2 S0 4 + 2H + + 2e ⁇
• the (+) plate is realized by electrochemical formation and subsequent cycling in sulfuric acid / perchloric acid, while the (-) plate is prepared by pasting activated carbon onto a graphite sheet.
• the said hybrid supercapacitor stores energy both in chemical and physical forms.
• the hybrid capacitors known in the prior art employ conventional Pb0 2 plates that require sizing and mixing of the active materials of appropriate compositions, pasting, drying, curing and formation. Such electrodes are not fully amenable to fast charge/discharge processes desired in a capacitor.
• an energy storage device (1) as shown in figure 1, comprising: a) substrate-integrated-lead-dioxide electrode (2), b) an activated carbon electrode (3), and c) a thixotropic inorganic-gel-polymer electrolyte (4) intercepted between the substrate - integrated-lead-dioxide electrode and the carbon electrode; an energy storage unit comprising plurality of energy storage device (1) as mentioned above, connected in series; a method of manufacturing an energy storage device (1), said method comprising acts of: a) preparing substrate- integrated lead dioxide electrode (2), b) preparing activated carbon electrode (3), and c) mounting the substrate-integrated lead dioxide electrode (2), the activated carbon electrode (3) with a thixotropic inorganic-gel-polymer electrolyte (4) in between the substrate- integrated lead dioxide and the carbon electrode to manufacture the energy storage device; a method of using energy-storage device (1) or energy storage unit as mentioned above, said method comprising act of conjugating
• Figure 1 shows schematic diagram of a cell [energy storage device (1)] from the 12V substrate- integrated Pb0 2 /activated-carbon ultracapacitor with inorganic thixotropic-gelled-electrolyte.
• the present invention relates to an energy storage device (1) comprising:
• the energy storage device (1) is a hybrid capacitor.
• the electrolyte acts as a separator.
• the electrolyte is selected from a group comprising sulfuric acid, methanesulfonic acid and perflourosulfonic acid, preferably sulfuric acid.
• the electrolyte is a thixtropic-gel obtained by cross-linking silica with sulfuric acid.
• the sulfuric acid has concentration ranging from about 4M to about 7M, preferably about 6M.
• the energy storage device (1) is of faradaic efficiency ranging from about 88% to about 90%, preferably about 89%.
• the present disclosure relates to an energy storage unit comprising plurality of energy storage device (1) as mentioned above, connected in series.
• the present disclosure relates to a method of manufacturing an energy storage device (1), said method comprising acts of:
• the electrolyte acts as a separator.
• the present invention relates to a method of using energy-storage device (1) or energy storage unit as mentioned above, said method comprising act of conjugating said energy-storage device or unit with electrical device for generating electrical energy to supply energy to devices in need thereof.
• the present invention relates to an inorganic thixotropic-gelled-polymer-electrolyte.
• the electrolyte is prepared by cross-linking fumed silica with sulfuric acid.
• the sulfuric acid has concentration ranging from about 4M to about 7M, preferably about 6M.; and wherein the electrolyte is capable of acting as a separator between electrodes of an energy storing device.
• the present invention is related to realizing substrate-integrated Pb0 2 / Activated-carbon hybrid ultracapacitor bereft of impurities.
• the hybrid ultra capacitors of the present invention are simple to assemble, bereft of impurities, and can be charged / discharged rapidly with faradaic efficiencies as high as 89%.
• the positive electrodes, namely substrate-integrated Pb0 2 are made by electrochemical formation of pre -polished and etched lead metal sheets.
• the substrate- integrated Pb0 2 is obtained by oxidizing PbSC>4 which is formed when lead sheets come in contact with sulfuric acid. Subsequent to their formation, the electrodes are washed copiously with de-ionized water to wash off all the impurities.
• electrodes in batteries are charged at C/10 rate (lOh duration) and discharged at C/5 rate (5h duration). If the battery electrodes are charged/discharged at the rate C (1 hour) or at higher rates, their cycle-life is affected. Faradaic efficiency of the battery electrodes depends on the particle size of the active materials, porosity of the electrode, internal resistance of the electrode, etc. The battery electrodes have low faradaic efficiency.
• the present invention provides electrochemically formed and substrate-integrated Pb0 2 as battery-type electrode, which can be charged and discharged at higher rates, while retaining faradaic efficiencies as high as 89% with thixotropic gelled polymeric electrolyte.
• the capacitance is calculated from the discharge curve using the equation:
• C(F) I(A) x t(s)/(V 2 -Vi) where V 2 is the voltage at the beginning of discharge and Vi is the voltage at the end of discharge.
• Pulsed cycle-life test involves the following four steps.
• Step 1 Charging the ultracapacitor at 3 A for 1 s.
• Step 2 Open-circuit voltage measurement for 5s.
• Step 3 Discharge the ultracapacitor at constant current at 3 A.
• Step 4 Open-circuit voltage measurement for 5s.
• the hybrid capacitor of the present invention is connected in series to obtain capacitors wherein the cell voltage gets added up, while the effective capacitance decreases, akin to conventional capacitor.
• the method of manufacturing substrate-integrated Pb0 2 /activated-carbon hybrid ultracapacitor (1) essentially comprises: preparing substrate-integrated lead dioxide electrode (2), preparing activated-carbon electrode (3), and mounting the substrate-integrated-lead-dioxide electrode (2), the activated-carbon electrode (3) with an inorganic thixotropic-gelled-polymeric-electrolyte (4) in between the substrate-integrated lead dioxide and the carbon electrode to manufacture the energy-storage device.
• the present invention discloses substrate-integrated Pb0 2 /activated-carbon hybrid ultracapacitors(HUC) with an inorganic thixotropic-gelled-polymer-electrolyte, which also acts as a separator.
• the gelled separator herein enhances the overall performance of the HUC with respect to critical parameters, such as capacitance and cycle-life.
• the devices of the present invention can be easily conjugated with electrical devices for generating electrical energy as supply energy to devices in need thereof.
• the technology of the instant invention is elaborated in detail with the help of following examples. However, the examples should not be construed as limiting the scope of the invention.
• Substrate-integrated- Pb0 2 electrodes are prepared by etching pre -polished lead sheets (thickness approximately 300 ⁇ ) in 1M HNO 3 for 60s and subsequently washed copiously with deionized water. The sheets were then immersed in 6 M aqueous H 2 SC>4 with 0.1 M HCIO 4 as additive at room temperature. On immersing in aqueous sulfuric acid, a thin layer of lead sulfate is formed on the surface of the lead sheet which is oxidized to Pb0 2 by using it as anode in an electrochemical cell fitted with a counter electrode. The process is repeated about five times to prepare the fully-formed substrate-integrated Pb0 2 electrodes.
• Activated-carbon electrodes are prepared by pasting activated carbon ink containing polyvinylidene difluoride (PVDF) as a binder.
• PVDF polyvinylidene difluoride
• a 12V substrate-integrated Pb0 2 /Activated carbon hybrid ultracapacitor was realized by connecting six single cells in series in a commercial lead-acid battery container. Each cell of this 12V hybrid ultracapacitor comprises 9 positive and 8 negative plates, each of size 4.5 cm x 7 cm, with the tag area of 0.5cm x 0.5 cm and 0.3 mm thickness for the positive plate and 0.8 mm thickness for negative plates.
• An inorganic thixotropic-gelled-polymer-electrolyte that was also used as a separator was prepared by cross-linking fumed silica with 6 M sulfuric acid.
• a unique method was used to interconnect the graphite electrodes.
• the tag portion of the negative electrodes is electroplated with tin, followed by electroplating with lead, which facilitates the graphite electrode tags to be soldered to each other.
• the graphite electrodes in each cell were soldered with lead by torch-melt method using an appropriately designed group-burning fixture. Subsequently, the cells were interconnected in series.
• the gelled electrolyte separator used herein enhances the overall performance of the HUC with respect to critical parameters such as cycle-life and capacitance.
• the comparative data for the 12V Absorbent Glass-Mat (AGM)-HUC and 12 V Gelled-HUC are given in Table 1 below.

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• Engineering & Computer Science (AREA)
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• Microelectronics & Electronic Packaging (AREA)
• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Electrochemistry (AREA)
• Electric Double-Layer Capacitors Or The Like (AREA)

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• 2012
  • 2012-07-18 WO PCT/IB2012/053658 patent/WO2013011464A1/en active Application Filing
  • 2012-07-18 KR KR1020147001400A patent/KR20140043788A/ko not_active Withdrawn
  • 2012-07-18 BR BR112014001141A patent/BR112014001141A2/pt not_active IP Right Cessation
  • 2012-07-18 CN CN201280035757.3A patent/CN103875050A/zh active Pending
  • 2012-07-18 JP JP2014520765A patent/JP2014521231A/ja active Pending
  • 2012-07-18 AU AU2012285404A patent/AU2012285404A1/en not_active Abandoned
  • 2012-07-18 EP EP12815395.4A patent/EP2735008A4/en not_active Withdrawn
• 2014
  • 2014-01-14 ZA ZA2014/00288A patent/ZA201400288B/en unknown

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