WO2022074689A1 - Supercapacitor for energy storage systems and related manufacturing method - Google Patents

Supercapacitor for energy storage systems and related manufacturing method Download PDF

Info

Publication number
WO2022074689A1
WO2022074689A1 PCT/IT2021/050286 IT2021050286W WO2022074689A1 WO 2022074689 A1 WO2022074689 A1 WO 2022074689A1 IT 2021050286 W IT2021050286 W IT 2021050286W WO 2022074689 A1 WO2022074689 A1 WO 2022074689A1
Authority
WO
WIPO (PCT)
Prior art keywords
coating
ceramic substrate
particles
auto
copper
Prior art date
Application number
PCT/IT2021/050286
Other languages
French (fr)
Inventor
Aldo GIRIMONTE
Matteo BERTOCCHI
Alessandro Fabbri
Loris BRUZZI
Original Assignee
Novac S.R.L.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Novac S.R.L. filed Critical Novac S.R.L.
Publication of WO2022074689A1 publication Critical patent/WO2022074689A1/en

Links

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
    • H01G11/22—Electrodes
    • H01G11/30—Electrodes characterised by their material
    • H01G11/50—Electrodes characterised by their material specially adapted for lithium-ion capacitors, e.g. for lithium-doping or for intercalation
    • 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
    • H01G11/84—Processes for the manufacture of hybrid or EDL capacitors, or components thereof
    • H01G11/86—Processes for the manufacture of hybrid or EDL capacitors, or components thereof specially adapted for electrodes
    • 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
    • H01G11/06—Hybrid capacitors with one of the electrodes allowing ions to be reversibly doped thereinto, e.g. lithium ion capacitors [LIC]
    • 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 invention refers to a supercapacitor obtained by assembling a plurality of particles of ceramic material , having the function of ionic conductor, coated with an electronic conductor material , with other uncoated particles of the same ceramic material .
  • the present invention also refers to a method for coating said particles of ceramic material of nanometer dimensions , by means of auto-catalytic copper deposition, said ceramic substrate being an ionic conductor and said copper coating being an electronic conductor .
  • a solution to the aforementioned problems is the use of devices , such as supercapacitors , capable of accumulating electric charge and which are characteri zed by high speci fic power and high capacity .
  • supercapacitors usually consist of two electrodes of various materials (usually aluminum) covered with activated carbon with a high surface area (up to 2000 m 2 /g) , a separator and an electrolyte .
  • the stored energy is higher than the capacity of a classic capacitor, since the charge separation occurs in the double electrode layer which occurs at molecular scale distances .
  • these supercapacitors present some unresolved problems such as poor resistance to both mechanical stress and high temperature operation .
  • One way of making these supercapacitors consists in the use of metal coatings, of solid state electrolyte nano-powders. In this case the powders act as an ion conductor and the metal coating acts as an electronic conductor.
  • a method of auto-catalytic deposition of metals on powders developed by G. Wen et al. (Department of Materials, Queen Mary and Westfield College, University of London, Mile End Road, London El 4NS, UK 2School) , provides that zirconium dioxide (ZrO 2 ) powders are effectively coated with a pure nickel layer by auto-catalytic deposition.
  • ZrO 2 zirconium dioxide
  • This method includes the following steps:
  • An object of the present invention is to propose a new type of supercapacitor obtained by suitably assembling said coated powders, whatever the nature of said powders and said coating material .
  • Another object of the present invention is to develop a new composite material for the realization of a new generation of supercapacitors, which overcome the limits constituted by the poor resistance both to mechanical stresses and to high temperature operation .
  • Said supercapacitors according to the invention will be made of solid state materials and able to function even in non-standard working conditions (high temperature and high mechanical stresses ) . They can also be designed speci fically for the chosen use without particular geometric constraints .
  • said electrodes comprise a plurality of coated particles mixed with uncoated particles , wherein said particles :
  • said material having the function of ionic conductor is a ceramic material , LATP and/or LAGP .
  • the method for coating a ceramic substrate of nanometer dimensions , by means of auto-catalytic copper deposition, said ceramic substrate being an ionic conductor and said copper coating being an electronic conductor comprises the following steps : sensitization of the surface of the ceramic substrate by immersion of said ceramic substrate in a sensitization solution containing stannous chloride (SnCl 2 ) ; activation of said surface of the ceramic substrate by immersion of said ceramic substrate in an activation solution containing palladium dichloride (PdCl 2 ) ;
  • CuSCg copper sulphate
  • NTA nitrilotriacetic acid
  • said nano-sized ceramic substrate comprising LAGP (Li (i +x) Al (x ) Ge ( 2-X ) (PO4) 3 ) and LATP
  • the deposition of a metallic material on an ionic conducting substrate generates an interface between the two materials that allows to perform the function of accumulation of electric charge , thanks to the behavior similar to that of an EDLC supercapacitor, i . e . accumulation of electric charge through the formation of an electrical double layer at the electrode/electrolyte interface .
  • the supercapacitors according to the invention have a wide range of application .
  • the supercapacitors according to the invention exceed in particular the limits of current supercapacitors , as they are also suitable for prohibitive use situations such as the presence of extreme temperatures or particular atmospheric conditions (such as space vacuum) .
  • Figure 1 ( a ) , (b ) shows the scheme of a supercapacitor according to the invention .
  • the ion conductor represents , together with the electronic conductor, the element necessary to obtain a complete electrochemical system .
  • these ionic conducting materials LAGP and LATP, in the form of nanoparticles were chosen .
  • Both selected materials belong to the Li-S ICON family ( Lithium Super Ionic CONductor ) , with very similar structures but with the replacement of di f ferent elements , skeleton consisting of phosphate tetrahedra and octahedra containing the main metal atoms ( germanium for LAGP and titanium for LATP) partially replaced with aluminum atoms . This partial replacement guarantees an increase in the ion mobility of the lithium ions ( Li ) .
  • Procedures must comply with laboratory safety regulations ; also for this reason the search for an auto-catalytic deposition bath has been focused on finding a composition that is as safe as possible , with the minimum number of dangerous reagents involved . In the same way, any environmental risks or risks related to the disposal of the substances used were assessed . Finally, the operating conditions and the deposition solution must ensure a chemical inertness for the substrate , for which instabilities are however reported only i f exposed to solutions with extreme pH values (between 1 and 14) , but certainly stable for intermediate values, (between 4 and 7) .
  • the amounts refer to the optimal formulation obtained during the study, analyzing the variation of the deposition rate based on pH, temperature and concentration of reducing and complexing agent .
  • composition variation consists in the addition of small quantities of nickel in solution .
  • the additions of nickel allow the inclusion of the same metal in the coating, thus creating catalytic sites for the oxidation reaction of sodium hypophosphite , resulting in an increase in the deposition rate and uni form growths .
  • nickel sul fate for example heptahydrate (NiSCg . Vl/hO) and potassium ferrocyanide (K4 Fe ( CN) e)
  • Nickel sulphate is necessary to add nickel ions in solution and thus obtain the co-deposition of nickel inside the copper matrix thus generating the catalytic sites for the oxidation of sodium hypophosphite
  • potassium ferrocyanide improves the quality, the finish of the coating and increases its density; in particular, with its addition, a decrease in the reduction current of copper ions ( Cu ++ ) and in the oxidation of sodium hypophosphite is obtained, a phenomenon explained by the adsorption of the species on the surface of the electrode , which thus leads to an opposition charge trans fer and nucleation, in addition to the ef fect of the potassium ferrocyanide itsel f which complexes the ions in solution, thus also decreasing their activity .
  • the traditional procedure usually involves a first phase of chemical attack on the surface , followed by sensiti zation and activation in a solution containing stannous chloride , palladium dichloride and hydrochloric acid .
  • the sensiti zation phase was adapted to the treatment of ceramic nano-powders ( LATP and LAGP ) , providing in this case the suspension and agitation of the materials within the solution containing the stannous chloride for 10 min .
  • the activation phase follows , during which the catalytic sites on the surface are generated; this step also has an expected duration of 10 min . Both sensiti zation and activation phases are carried out at room temperature .
  • Awareness raising and activation are carried out in two steps with separate solutions .
  • the complete procedure , according to the invention, for the auto-catalytic deposition of copper on LATP and LAGP powders involves the following steps .
  • Dispersion the LAGP and LATP particles are inserted in distilled water and dispersed by ultrasound with a duration of 15 a 20 min . 2.
  • First washing the LAGP and LATP particles are separated by centrifugation.
  • Sensitization the dry particles of LAGP and LATP are dispersed in the sensitization solution containing the tin compound, subjecting them to a dispersion procedure by means of an ultrasonic bath lasting about 10 min.
  • Second washing the particles of LAGP and LATP together with the sensitization solution are separated from it by centrifugation, the sensitization solution is then eliminated and distilled water is added; the particles are subjected to dispersion by means of an ultrasonic bath and are again separated from the distilled water by centrifugation.
  • the LAGP and LATP particles are immersed in the activation solution containing the palladium compound and subjected to dispersion by means of an ultrasonic bath for the duration of 10 min.; the dispersion is carried out by centrifugation to separate the particles from the activation solution which is eliminated, then the particles are subjected to drying at room temperature , possibly using volatile solvents for quick drying .
  • Auto-catalytic deposition the dry LAGP and LATP particles subj ected to the previous activation step are immersed in the auto-catalytic deposition solution; the particles are then subj ected to a dispersion procedure within the auto-catalytic deposition solution using an ultrasonic bath for a duration of 10 min .
  • the auto-catalytic deposition solution in which the particles are di spersed is placed in a water bath at the optimi zed temperature of 50 a 80 ° C .
  • the ultrasonic bath, used during the auto-catalytic deposition guarantees the correct dispersion of the particles during said deposition .
  • the LATP and/or LAGP particles as they are and coated according to the procedure described, are then used for the production of supercapacitor electrodes .
  • the particles of LATP and/or LAGP coated with the metal material through auto-catalytic deposition are mixed together with the same uncoated starting material , thus obtaining a structure with the particles with metallic coating in contact , forming a three- dimensional network inserted inside the solid electrolyte .
  • the percentage in weight of said coated particles , necessary to obtain a conductive network (within a single electrode ) varies from 20% to 90% ; the final quantity necessary for the construction of the electrode depends on the average si ze of the initial substrate on which the auto-catalytic deposition procedure is carried out , and on its agglomeration state .
  • the percentage in weight between coated material and untreated material to be mixed can be varied with the aim of optimi zing the conductivity of the electrode .
  • the mixed material can be subj ected to a sintering heat treatment in order to consolidate the single electrode and increase the ionic conductivity of the solid electrolyte .
  • the high surface development of the nanoparticles constituting the substrate makes it possible to obtain electrodes with a very high specific surface, which results in an increase in the capacity of the devices.
  • (1) designates said mixture consisting of coated particles and uncoated particles.
  • the coated and agglomerated LATP and/or LAGP particles constitute a conductive network (2)
  • the uncoated and agglomerated LATP and/or LAGP particles constitute the ionic conductor (3) .
  • the conductive network (2) and the ionic conductor (3) constitute the electrodes of a capacitor.
  • This system just described constitutes a supercapacitor cell, according to the invention.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Chemical & Material Sciences (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Warehouses Or Storage Devices (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

The invention refers to a supercapacitor obtained by assembling a plurality of particles of ceramic material, having the function of ionic conductor, coated with an electronic conductor material, with other uncoated particles of the same ceramic material. The present invention also refers to a method for coating said particles of ceramic material of nanometer dimensions, by means of auto- catalytic copper deposition, said ceramic substrate being an ionic conductor and said copper coating being an electronic conductor.

Description

SUPERCAPACITOR FOR ENERGY STORAGE SYSTEMS AND RELATED MANUFACTURING METHOD
The invention refers to a supercapacitor obtained by assembling a plurality of particles of ceramic material , having the function of ionic conductor, coated with an electronic conductor material , with other uncoated particles of the same ceramic material .
The present invention also refers to a method for coating said particles of ceramic material of nanometer dimensions , by means of auto-catalytic copper deposition, said ceramic substrate being an ionic conductor and said copper coating being an electronic conductor .
In some areas , such as the automotive industry, it is necessary to have systems characteri zed by high speci fic power, capable of providing large amounts of energy in short intervals of time . Most energy storage systems , such as classic lithium-ion batteries , often have to be oversi zed in order to meet the demand in terms of energy and deliverable power . The geometries of the devices currently in use are often standardi zed, therefore not customi zable by those who have to use them within a system, so some design precautions are necessary (heat management , position, occupied volume , added mass ) to be able to make the energy storage system compatible with the actual user .
A solution to the aforementioned problems is the use of devices , such as supercapacitors , capable of accumulating electric charge and which are characteri zed by high speci fic power and high capacity .
As known, supercapacitors usually consist of two electrodes of various materials (usually aluminum) covered with activated carbon with a high surface area (up to 2000 m2/g) , a separator and an electrolyte .
The stored energy is higher than the capacity of a classic capacitor, since the charge separation occurs in the double electrode layer which occurs at molecular scale distances .
However, these supercapacitors present some unresolved problems such as poor resistance to both mechanical stress and high temperature operation . One way of making these supercapacitors consists in the use of metal coatings, of solid state electrolyte nano-powders. In this case the powders act as an ion conductor and the metal coating acts as an electronic conductor.
A method of auto-catalytic deposition of metals on powders, developed by G. Wen et al. (Department of Materials, Queen Mary and Westfield College, University of London, Mile End Road, London El 4NS, UK 2School) , provides that zirconium dioxide (ZrO2) powders are effectively coated with a pure nickel layer by auto-catalytic deposition.
This method includes the following steps:
- sensitization and activation of the surface of said ceramic powders;
- auto-catalytic deposition of nickel by immersion in a solution comprising a nickel salt.
An object of the present invention is to propose a new type of supercapacitor obtained by suitably assembling said coated powders, whatever the nature of said powders and said coating material .
Another object of the present invention is to develop a new composite material for the realization of a new generation of supercapacitors, which overcome the limits constituted by the poor resistance both to mechanical stresses and to high temperature operation .
Said supercapacitors according to the invention will be made of solid state materials and able to function even in non-standard working conditions (high temperature and high mechanical stresses ) . They can also be designed speci fically for the chosen use without particular geometric constraints .
These and other obj ects are achieved with a device and a method according to their respective independent claims .
The device is a supercapacitor of the type comprising two electrodes separated by an electrolyte and is characteri zed in that :
- said electrodes comprise a plurality of coated particles mixed with uncoated particles , wherein said particles :
* consist of a material having the ionic conductor function of Li ( i+x ) Al ( x ) Ge <2-X) ( PO4 ) 3 ( LAGP ) and/or Li (i+x) Al (X) Ti (2-x) ( PO4 ) 3 ( LATP ) ;
* they are coated with a metal lic material having the function of electronic conductor ; the mixture being consolidated by sintering heat treatment thus providing a structure m which the particles of LATP and/or LAGP with metallic and agglomerated coatings are in contact and constitute a conductive network 2 , while the particles of LATP and/or LAGP do not coated and agglomerated form an ionic conductor 3 .
According to a preferred embodiment , said material having the function of ionic conductor is a ceramic material , LATP and/or LAGP .
By varying the potential of the metal , an accumulation of electric charge is generated which is compensated by a motion of ions within the solid state electrolyte . In this way, a system similar to a classic condenser is created .
By coupling two electrodes operating on the basis of this technology, an overall system can be obtained that can be assimilated to two capacitors connected in series with each other ( the two electrodes separated from the electrolyte ) .
The method for coating a ceramic substrate of nanometer dimensions , by means of auto-catalytic copper deposition, said ceramic substrate being an ionic conductor and said copper coating being an electronic conductor, comprises the following steps : sensitization of the surface of the ceramic substrate by immersion of said ceramic substrate in a sensitization solution containing stannous chloride (SnCl2) ; activation of said surface of the ceramic substrate by immersion of said ceramic substrate in an activation solution containing palladium dichloride (PdCl2) ;
- auto-catalytic deposition of copper; wherein said auto-catalytic deposition of copper occurs by immersion in a solution for autocatalytic deposition comprising the following components :
- copper sulphate (CuSCg) , acting as a source of copper ions;
- nitrilotriacetic acid (NTA) , with the function of complexing agent for the copper ions Cu++;
- sodium hypophosphite (NaH2PO2) , with the function of reducing agent;
- sodium acetate (CHsCOONa) , with the function of buffer to keep the pH of said solution constant; said nano-sized ceramic substrate comprising LAGP (Li (i+x)Al (x) Ge (2-X) (PO4) 3) and LATP
(Li (i+x)Al (x) Ti (2-X) (PO4) 3) , alternatively or together; said auto-catalytic deposition occurs at a temperature of 50 e 80 C and a pH substantially between 3 and 7 .
The deposition of a metallic material on an ionic conducting substrate generates an interface between the two materials that allows to perform the function of accumulation of electric charge , thanks to the behavior similar to that of an EDLC supercapacitor, i . e . accumulation of electric charge through the formation of an electrical double layer at the electrode/electrolyte interface .
Preferred embodiments and non-trivial variants of the present invention are the subj ect matter of the dependent claims .
The supercapacitors according to the invention have a wide range of application .
In particular, they deal with a technology suitable for use in any application that is characteri zed by an impulsive , non-constant energy demand and/or high power requirements , for example in the case of electric motors . Some examples are the automotive sector, the electric micro-mobility sector, electric boats , aerospace .
The supercapacitors according to the invention exceed in particular the limits of current supercapacitors , as they are also suitable for prohibitive use situations such as the presence of extreme temperatures or particular atmospheric conditions ( such as space vacuum) .
The deposition of a metal using as substrate said ceramic particles of solid electrolyte LATP and LAGP, allows to have advantages when compared with other methods of construction of super- capacitive devices , such as :
- shorter process time ;
- better adhesion of the electronic conductor to the ionic conductor in the solid state ; electronic conductor/ ion conductor contact area equal to 100% ;
- easily scalable procedure ;
- lower resistance of the electrode interface in the device thanks to the metallic nature of the electronic conductor .
It will be immediately obvious that innumerable variations and modi fications ( for example relating to shape , dimensions , arrangements and parts with equivalent functionality) can be made to what is described without departing from the scope of the invention, as appears from the attached claims . It is understood that all the attached claims form an integral part of the present description .
The present invention will be better described by a preferred embodiment , given by way of non-limiting example , with reference to the attached drawings , in which
Figure 1 ( a ) , (b ) shows the scheme of a supercapacitor according to the invention .
The ion conductor represents , together with the electronic conductor, the element necessary to obtain a complete electrochemical system . Given the basic requirements of good ionic conductivity at room temperature , stability of the material to exposure in air, cost of the material and high surface development , these ionic conducting materials LAGP and LATP, in the form of nanoparticles , were chosen . Both selected materials belong to the Li-S ICON family ( Lithium Super Ionic CONductor ) , with very similar structures but with the replacement of di f ferent elements , skeleton consisting of phosphate tetrahedra and octahedra containing the main metal atoms ( germanium for LAGP and titanium for LATP) partially replaced with aluminum atoms . This partial replacement guarantees an increase in the ion mobility of the lithium ions ( Li ) .
The research carried out led to the optimi zation of a procedure for the auto-catalytic deposition of copper .
To obtain an electronic conductor with good electrical conductivity, it is necessary to make a deposit of pure metal , without the presence of precipitates or secondary phases . However, in order to obtain a fast and uni form growth of the copper coating, the presence of catalytic sites within the copper matrix is necessary, as will be speci fied below .
Procedures must comply with laboratory safety regulations ; also for this reason the search for an auto-catalytic deposition bath has been focused on finding a composition that is as safe as possible , with the minimum number of dangerous reagents involved . In the same way, any environmental risks or risks related to the disposal of the substances used were assessed . Finally, the operating conditions and the deposition solution must ensure a chemical inertness for the substrate , for which instabilities are however reported only i f exposed to solutions with extreme pH values (between 1 and 14) , but certainly stable for intermediate values, (between 4 and 7) .
From a research carried out in the literature, an auto-catalytic deposition procedure was selected for the realization of a metallic coating in pure copper. The reagents, functions, concentrations are reported in the TAB. 1, while the reaction conditions are reported in TAB. Ibis; these values are valid if applied to the treatment of a quantity of dust equal to 2.5 g/L, for greater quantities of dust it is necessary to reduce the concentration of the reagents.
TAB. 1
Figure imgf000013_0001
TAB. Ibis
Figure imgf000013_0002
The amounts refer to the optimal formulation obtained during the study, analyzing the variation of the deposition rate based on pH, temperature and concentration of reducing and complexing agent .
Research has shown that the ideal process conditions are obtained with a temperature of 50 a 80 ° C and a pH of 3 a 7 .
With the introduction of the PEG- 600 surfactant in solution, a decrease in the resistivity of the coating, a decrease in surface roughness and an improvement in mechanical properties was highlighted . With this treatment , it is possible to obtain a pure copper layer on the nanoparticles .
After the analysis of the reagents involved, a change in the composition of the bath was expected in order to avoid known ef fects of slowing the growth of the copper coating . These slowdowns are attributable to a poor reactivity of one of the reagents ( sodium hypophosphite ) on the previous copper deposit , as the pure copper coating is not perfectly catalytic for the oxidation reaction of the reducing agent . The composition variation consists in the addition of small quantities of nickel in solution . The additions of nickel allow the inclusion of the same metal in the coating, thus creating catalytic sites for the oxidation reaction of sodium hypophosphite , resulting in an increase in the deposition rate and uni form growths . The additives needed to achieve the inclusion of nickel in the coating are nickel sul fate , for example heptahydrate (NiSCg . Vl/hO) and potassium ferrocyanide (K4 Fe ( CN) e) • Nickel sulphate is necessary to add nickel ions in solution and thus obtain the co-deposition of nickel inside the copper matrix thus generating the catalytic sites for the oxidation of sodium hypophosphite , while potassium ferrocyanide improves the quality, the finish of the coating and increases its density; in particular, with its addition, a decrease in the reduction current of copper ions ( Cu++ ) and in the oxidation of sodium hypophosphite is obtained, a phenomenon explained by the adsorption of the species on the surface of the electrode , which thus leads to an opposition charge trans fer and nucleation, in addition to the ef fect of the potassium ferrocyanide itsel f which complexes the ions in solution, thus also decreasing their activity . A similar ef fect with a similar mechanism is attributable to another reagent present in the bath, the surfactant Polyethylene Glycol- 600 ( PEG- 600 ) . The addition of these secondary additives took place with the concentrations reported in TAB . 2 .
TAB . 2
Figure imgf000016_0001
Since it is necessary to deposit the copper on electrically insulating and non-catalytic substrates to the expected electrochemical reaction, it is necessary to functionali ze the surface . This occurs classically through the preliminary deposition of small quantities of catalytic metal ( for example palladium) .
The traditional procedure usually involves a first phase of chemical attack on the surface , followed by sensiti zation and activation in a solution containing stannous chloride , palladium dichloride and hydrochloric acid .
The concentrations of the reagents are reported in the TAB . 3 . TAB . 3
Figure imgf000017_0001
The sensiti zation phase was adapted to the treatment of ceramic nano-powders ( LATP and LAGP ) , providing in this case the suspension and agitation of the materials within the solution containing the stannous chloride for 10 min . The activation phase follows , during which the catalytic sites on the surface are generated; this step also has an expected duration of 10 min . Both sensiti zation and activation phases are carried out at room temperature .
Awareness raising and activation are carried out in two steps with separate solutions .
The complete procedure , according to the invention, for the auto-catalytic deposition of copper on LATP and LAGP powders involves the following steps .
1 . Dispersion : the LAGP and LATP particles are inserted in distilled water and dispersed by ultrasound with a duration of 15 a 20 min . 2. First washing: the LAGP and LATP particles are separated by centrifugation.
3. Drying: the LAGP and LATP particles are dried in an oven at a temperature of 60 °C.
4. Sensitization: the dry particles of LAGP and LATP are dispersed in the sensitization solution containing the tin compound, subjecting them to a dispersion procedure by means of an ultrasonic bath lasting about 10 min.
5. Second washing: the particles of LAGP and LATP together with the sensitization solution are separated from it by centrifugation, the sensitization solution is then eliminated and distilled water is added; the particles are subjected to dispersion by means of an ultrasonic bath and are again separated from the distilled water by centrifugation.
6. Activation: the LAGP and LATP particles are immersed in the activation solution containing the palladium compound and subjected to dispersion by means of an ultrasonic bath for the duration of 10 min.; the dispersion is carried out by centrifugation to separate the particles from the activation solution which is eliminated, then the particles are subjected to drying at room temperature , possibly using volatile solvents for quick drying .
7 . Auto-catalytic deposition : the dry LAGP and LATP particles subj ected to the previous activation step are immersed in the auto-catalytic deposition solution; the particles are then subj ected to a dispersion procedure within the auto-catalytic deposition solution using an ultrasonic bath for a duration of 10 min . The auto-catalytic deposition solution in which the particles are di spersed is placed in a water bath at the optimi zed temperature of 50 a 80 ° C . The ultrasonic bath, used during the auto-catalytic deposition, guarantees the correct dispersion of the particles during said deposition .
The LATP and/or LAGP particles , as they are and coated according to the procedure described, are then used for the production of supercapacitor electrodes .
In order to obtain electrodes with a high speci fic surface and perfectly integrated with the solid state electrolyte , the particles of LATP and/or LAGP coated with the metal material through auto-catalytic deposition are mixed together with the same uncoated starting material , thus obtaining a structure with the particles with metallic coating in contact , forming a three- dimensional network inserted inside the solid electrolyte .
The percentage in weight of said coated particles , necessary to obtain a conductive network (within a single electrode ) varies from 20% to 90% ; the final quantity necessary for the construction of the electrode depends on the average si ze of the initial substrate on which the auto-catalytic deposition procedure is carried out , and on its agglomeration state . The percentage in weight between coated material and untreated material to be mixed can be varied with the aim of optimi zing the conductivity of the electrode .
Generally, a percentage of about 70% by weight of coated nanoparticles , inserted into the mixture , has led to optimal results , i . e . a compromise between good conductivity and increased capacity linked to surface development .
Once the mixed material has been obtained, it can be subj ected to a sintering heat treatment in order to consolidate the single electrode and increase the ionic conductivity of the solid electrolyte .
The high surface development of the nanoparticles constituting the substrate makes it possible to obtain electrodes with a very high specific surface, which results in an increase in the capacity of the devices.
In Figure 1 (a) , (1) designates said mixture consisting of coated particles and uncoated particles. The coated and agglomerated LATP and/or LAGP particles constitute a conductive network (2) , while the uncoated and agglomerated LATP and/or LAGP particles constitute the ionic conductor (3) . The conductive network (2) and the ionic conductor (3) constitute the electrodes of a capacitor.
By coupling two electrodes (1) like the one described with a layer (4) consisting of only the uncoated ionic conductor (FIG. 1 (b) ) , an overall system can be obtained which can be assimilated to two capacitors connected in series with each other.
This system just described constitutes a supercapacitor cell, according to the invention.

Claims

1. Supercapacitor of a type comprising two electrodes separated by an electrolyte, characterized in that said electrodes comprise a plurality of coated particles mixed with uncoated particles, wherein said particles:
- consist of a material having the ionic conductor function of Li (i+x) Al (x) Ge (2-X) ( PO4 ) 3 (LAGP) and/or Li (i+x) Al <x) Ti (2-x> ( PO4 ) 3 ( LATP ) ;
- are coated with a metallic material having the function of electronic conductor; said mixture being consolidated by a sintering heat treatment, thereby providing a structure in which the particles of LATP and/or LAGP with metallic and agglomerated coatings are in contact and constitute a conductive network (2) , while the particles of LATP and/or uncoated and agglomerated LAGPs form an ionic conductor (3) .
2. Supercapacitor according to claim 1, characterized in that said material having the function of ionic conductor is a ceramic material.
3. Supercapacitor according to claim 2, characterized in that said ceramic material is LATP and/or LAGP.
4. Method for coating a ceramic substrate of nanometer dimensions , by means of auto-catalytic copper deposition, said ceramic substrate being an ionic conductor and said copper coating being an electronic conductor, characteri zed in that it comprises the following steps :
- sensiti zation of the substrate surface ; activation of the surface of the ceramic substrate ;
- auto-catalytic deposition of copper ; wherein :
- the sensiti zation of the surface of the ceramic substrate occurs by immersing said ceramic substrate in a sensiti zation solution containing stannous chloride ( SnC12 ) ;
- the activation of said surface of the ceramic substrate occurs by immersion of said ceramic substrate in an activation solution containing palladium dichloride ( PdC12 ) ;
- the auto-catalytic deposition of copper occurs by immersion in a solution for the auto-catalytic deposition comprising the following components :
- copper sulphate ( CuSO4 ) , acting as a source o f copper ions ;
- nitrilotriacetic acid (NTA) , with the function of complexing agent for the copper ions Cu++ ; - sodium hypophosphite (NaH2PO2) , with the function of reducing agent;
- sodium acetate (CHsCOONa) , with the function of buffer to keep the pH of said solution constant; said nano-sized ceramic substrate comprising LAGP (Li d+x)Al (X) Ge (2-x) (PO4) 3) and LATP (Li (i+x)Al (x) Ti (2-X) (PO4) 3) , alternatively or together, and said auto-catalytic deposition occurring at a temperature of 50 a 80 °C and at a pH substantially between 3 and 7.
5. Method for coating a ceramic substrate according to claim 4, characterized in that said solution for the auto-catalytic copper deposition further comprises nickel sulphate (NiSCg) in order to add nickel ions in said solution and thus obtaining the co-deposition of nickel inside said copper coating, thus generating catalytic sites for the oxidation of said sodium hypophosphite, with a consequent increase in the copper deposition rate and uniform growth of the coating.
6. Method for coating a ceramic substrate according to claim 4, characterized in that said solution for the auto-catalytic deposition of copper further comprises potassium ferrocyanide (K4Fe(CN) e) , in order to improve the finish of the coating and increase its density.
7. Method for coating a ceramic substrate according to claim 4, characterized in that said solution for the auto-catalytic deposition of copper further comprises Polyethylene Glycol 600, PEG 600, with the function of surfactant, in order to obtain a decrease in resistivity of the coating, a decrease in surface roughness and an improvement in mechanical properties.
8. Method for coating a ceramic substrate according to at least one of claims 4 to 7, characterized in that said LATP or LAGP particles are subjected to a treatment which includes the following steps:
- a first wash;
- drying;
- sensitization;
- a second wash;
- activation;
- auto-catalytic deposition.
9. Method for coating a ceramic substrate according to claim 8, characterized in that in the sensitization step, said dry LATP and/or LAGP particles are dispersed in said sensitization solution containing said stannous chloride (SnC12) , subjecting them a dispersion procedure by means of an ultrasonic bath lasting 10 mm .
10 . Method for coating a ceramic substrate according to claim 8 , characteri zed in that in the step of said second washing, said LATP and/or LAGP particles are subj ected to the following treatments : separation from said sensiti zing solution by centri fugation; elimination of the sensiti zation solution and addition of distilled water ;
- dispersion by ultrasonic bath; separation from distilled water by centri fugation .
11 . Method for coating a ceramic substrate according to claim 8 , characteri zed in that in the step of said activation, said LATP and/or LAGP particles are subj ected to the following treatments :
- immersion in said activation solution containing said palladium compound; dispersion through ultrasonic bath for the duration of 10 min;
- centri fugation to separate the particles from the activation solution which is eliminated; drying at room temperature , using volatile solvents for quick drying .
12 . Method for coating a ceramic substrate according to claim 8 , characteri zed in that in the step of said auto-catalytic deposition, said dry LATP and/or LAGP particles are subj ected to the following treatments : dispersion in the solution for auto-catalytic deposition by means of an ultrasonic bath for a duration of about 10 min; - maintenance of the dispersion at a temperature of
50 80 ° C .
PCT/IT2021/050286 2020-10-07 2021-09-21 Supercapacitor for energy storage systems and related manufacturing method WO2022074689A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT102020000023566A IT202000023566A1 (en) 2020-10-07 2020-10-07 New energy storage system and related manufacturing method
IT102020000023566 2020-10-07

Publications (1)

Publication Number Publication Date
WO2022074689A1 true WO2022074689A1 (en) 2022-04-14

Family

ID=74046076

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IT2021/050286 WO2022074689A1 (en) 2020-10-07 2021-09-21 Supercapacitor for energy storage systems and related manufacturing method

Country Status (2)

Country Link
IT (1) IT202000023566A1 (en)
WO (1) WO2022074689A1 (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110262836A1 (en) * 2008-06-20 2011-10-27 University Of Dayton Lithium-air cell incorporating lithium aluminum germanium phosphate cathode
US20160027591A1 (en) * 2013-03-15 2016-01-28 Ngk Spark Plug Co., Ltd. Capacitor
WO2019212007A1 (en) * 2018-05-02 2019-11-07 日本特殊陶業株式会社 Ionic conductor and electricity storage device
DE102018221828A1 (en) * 2018-12-14 2020-06-18 Volkswagen Aktiengesellschaft Coating of anode and cathode active materials with high-voltage stable solid electrolytes and an electron conductor in a multi-layer system and lithium-ion battery cell
EP3696890A1 (en) * 2019-02-13 2020-08-19 Robert Bosch Battery Systems LLC Reduced llto particles with electronically insulating coatings

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20110262836A1 (en) * 2008-06-20 2011-10-27 University Of Dayton Lithium-air cell incorporating lithium aluminum germanium phosphate cathode
US20160027591A1 (en) * 2013-03-15 2016-01-28 Ngk Spark Plug Co., Ltd. Capacitor
WO2019212007A1 (en) * 2018-05-02 2019-11-07 日本特殊陶業株式会社 Ionic conductor and electricity storage device
DE102018221828A1 (en) * 2018-12-14 2020-06-18 Volkswagen Aktiengesellschaft Coating of anode and cathode active materials with high-voltage stable solid electrolytes and an electron conductor in a multi-layer system and lithium-ion battery cell
EP3696890A1 (en) * 2019-02-13 2020-08-19 Robert Bosch Battery Systems LLC Reduced llto particles with electronically insulating coatings

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
G.WEN: "Department of Materials", UNIVERSITY OF LONDON

Also Published As

Publication number Publication date
IT202000023566A1 (en) 2021-01-07

Similar Documents

Publication Publication Date Title
Jian et al. Flexible diamond fibers for high‐energy‐density zinc‐ion supercapacitors
Yedluri et al. Enhanced electrochemical performance of nanoplate nickel cobaltite (NiCo 2 O 4) supercapacitor applications
Zhang et al. In situ reconstructed Zn doped FexNi (1− x) OOH catalyst for efficient and ultrastable oxygen evolution reaction at high current densities
Daneshvar et al. Porous SnO2–CuxO nanocomposite thin film on carbon nanotubes as electrodes for high performance supercapacitors
Samuel et al. Nickel ferrite beehive-like nanosheets for binder-free and high-energy-storage supercapacitor electrodes
Hassan et al. Highly stable binary composite of nickel silver sulfide (NiAg2S) synthesized using the hydrothermal approach for high‐performance supercapattery applications
Yang et al. Regulating uniform Zn deposition via hybrid artificial layer for stable aqueous Zn-ion batteries
Sadan et al. Enhanced rate and cyclability of a porous Na 3 V 2 (PO 4) 3 cathode using dimethyl ether as the electrolyte for application in sodium-ion batteries
Arvas et al. Fabrication of high-performance symmetrical coin cell supercapacitors by using one step and green synthesis sulfur doped graphene powders
Zhang et al. Effective improvement of electrochemical performance of electrodeposited MnO2 and MnO2/reduced graphene oxide supercapacitor materials by alcohol pretreatment
Khalid et al. A general potentiodynamic approach for red phosphorus and sulfur nanodot incorporation on reduced graphene oxide sheets: metal-free and binder-free electrodes for supercapacitor and hydrogen evolution activities
Pei et al. Porous Si‐Cu3Si‐Cu Microsphere@ C Core–Shell Composites with Enhanced Electrochemical Lithium Storage
Jagadale et al. Binder‐Free Electrodes of CoAl Layered Double Hydroxide on Carbon Fibers for All‐Solid‐State Flexible Yarn Supercapacitors
WO2019176956A1 (en) Titanium base material, method for producing titanium base material, electrode for water electrolysis, and water electrolysis device
Jin et al. Hierarchical Ni@ Ni (OH) 2 core-shell hybrid arrays on cotton cloth fabricated by a top-down approach for high-performance flexible asymmetric supercapacitors
Targholi et al. Facile synthesis of copper hexacyanoferrate/graphene nanocomposite for electrochemical energy storage
Frąckowiak et al. Electrochemical capacitor performance of nanotextured carbon/transition metal dichalcogenides composites
Liu et al. A facile synthesis of Ni 0.85 Se@ Cu 2− x Se nanorods as high-performance supercapacitor electrode materials
Kazemi et al. Electrodeposited Ni (OH) 2 nanostructures on electro-etched carbon fiber paper for highly stable supercapacitors
Hameed et al. Ni–P–SnO2/C composite: synthesis, characterization and electrocatalytic activity for methanol oxidation in KOH solution
Liu et al. Microwave synthesis of NiSe2 nanomaterials on carbon fiber felt for flexible supercapacitors and oxygen evolution reaction
Chakrabarti et al. Practical aspects of electrophoretic deposition to produce commercially viable supercapacitor energy storage electrodes
Chen et al. A multifunctional gradient coating enables dendrite-free and side reaction-free zinc anodes for stable zinc-ion batteries
Sun et al. Redox Chemistry of Mn2+ on N‐Doped Porous Carbon Fibers for High‐Performance Electrochemical Energy Storage
WO2022074689A1 (en) Supercapacitor for energy storage systems and related manufacturing method

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 21794194

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 21794194

Country of ref document: EP

Kind code of ref document: A1