Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M8/00—Fuel cells; Manufacture thereof
  • H01M8/04—Auxiliary arrangements, e.g. for control of pressure or for circulation of fluids
  • H01M8/04082—Arrangements for control of reactant parameters, e.g. pressure or concentration
  • H01M8/04201—Reactant storage and supply, e.g. means for feeding, pipes
  • H01M8/04216—Reactant storage and supply, e.g. means for feeding, pipes characterised by the choice for a specific material, e.g. carbon, hydride, absorbent
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
  • C01B3/0005—Reversible uptake of hydrogen by an appropriate medium, i.e. based on physical or chemical sorption phenomena or on reversible chemical reactions, e.g. for hydrogen storage purposes ; Reversible gettering of hydrogen; Reversible uptake of hydrogen by electrodes
  • C01B3/001—Reversible uptake of hydrogen by an appropriate medium, i.e. based on physical or chemical sorption phenomena or on reversible chemical reactions, e.g. for hydrogen storage purposes ; Reversible gettering of hydrogen; Reversible uptake of hydrogen by electrodes characterised by the uptaking medium; Treatment thereof
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B33/00—Silicon; Compounds thereof
  • C01B33/02—Silicon
• • C—CHEMISTRY; METALLURGY
  • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
  • C25F—PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROM OBJECTS; APPARATUS THEREFOR
  • C25F3/00—Electrolytic etching or polishing
  • C25F3/02—Etching
  • C25F3/12—Etching of semiconducting materials
• • 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
  • Y02E60/30—Hydrogen technology
  • Y02E60/32—Hydrogen storage
• • 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
  • Y02E60/30—Hydrogen technology
  • Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
• • 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
  • Y02E60/30—Hydrogen technology
  • Y02E60/50—Fuel cells
• • 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
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
  • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

• the present invention relates to a hydrogen reservoir, at atmospheric pressure, based on silicon nanostructures. It applies in particular to the field of fuel cells (nano-, micro- and macro-cells). It can also be applied to the field of hydrogen engines (nano-, micro- and macro-engines).
• Hydrogen is currently a very strongly anticipated energy carrier. Its storage is one of the crucial points in the development of fuel cells, whatever the type of application, or of small devices. It is known to store hydrogen in cryogenic tanks or under pressure. These solutions are not compatible, and reasonably possible, in certain fields and in particular for portable devices (telephones, computers, small electronic devices). This observation is valid to a lesser extent in the field of land transport. It is in fact not easy to produce reservoirs under the very high pressures (greater than 500 bars) necessary to have sufficient autonomy. In addition, the storage under very high pressure clearly poses the security problem. As for cryogenic solutions, they are penalized by the poor efficiency of the hydrogen liquefaction process.
• the invention proposes a new hydrogen tank whose volume and mass storage capacities of hydrogen are comparable or better than those of current storage means. Storage can be obtained in a simple manner and at atmospheric pressure, which is a guarantee of security.
• This tank can be manufactured in massive quantities and at low cost by techniques well known in the silicon industry. The manufacture of this tank is compatible with various technologies for producing fuel cells of different power ranges.
• the invention therefore has for its object a hydrogen reservoir comprising a substance capable of storing hydrogen, characterized in that said substance consists of nanostructured silicon.
• nano-structured silicon is meant a nano-structure having a high specific surface (greater than 100 m 2 / cm 3 ), that is to say a nano-structure which contains nano-crystallites or nano- silicon particles of various geometric shapes, interconnected or not, of which at least one dimension is less than or equal to 100 nm and the sum of the surfaces of each nano- crystallite and / or nanoparticle is larger than the planar surface occupied by the nanostructure.
• said substance consists of meso-porous and / or nano-porous silicon nanostructures.
• the initial morphology of the silicon to be nanostructured can be chosen from monocrystalline silicon, polycrystalline silicon and amorphous silicon.
• the substance consists of nanostructured, porous and compacted silicon or, more advantageously still, nano-structured, porous, crushed and compacted silicon.
• the subject of the invention is also a method of manufacturing a hydrogen reservoir, characterized in that it consists in porosifying silicon to obtain nano-structures of meso-porous or nano-porous silicon and in storing therein hydrogen by creating chemical bonds between hydrogen and silicon.
• the creation of chemical bonds between hydrogen and silicon can be obtained via an acid.
• the manufacturing process can consist in subjecting monocrystalline, polycrystalline or amorphous silicon to an electrochemical anodization using an acid and making it possible to simultaneously obtain the porosification of the silicon and the storage of hydrogen.
• the acid used can be hydrofluoric acid.
• the manufacturing process can further comprise a subsequent step consisting in compacting
• the invention also relates to a method of using a hydrogen tank as defined above, characterized in that since hydrogen is stored in the tank, the method comprises a step consisting in causing rupture chemical bonds between hydrogen and silicon to extract hydrogen.
• the rupture of the chemical bonds between hydrogen and silicon can be caused by an energy supply chosen from chemical energy, thermal energy, mechanical energy (for example released following compression), the energy of a radiation and the energy of an electric field.
• the method of use comprises a step of recharging the reservoir consisting in bringing said substance into contact with an acid.
• the invention also relates to a fuel cell system, a fuel cell, a hydrogen engine system or a hydrogen engine comprising such a hydrogen tank.
• the porosification of silicon, monocrystalline, polycrystalline or amorphous, on a scale nanometric by electrochemical anodization allows the creation of nanometric pores causing embrittlement of its initial structure, embrittlement which is advantageously exploited by the invention.
• the size of the nanocrystals obtained and the level of embrittlement of the nanostructured layer are determined as a function of the substrate initially chosen and of the anodization parameters (anodization current, composition of the electrochemical solution). Two typical morphologies can be obtained which can be designated under the expressions “nano-sponge” and “nano-column”.
• This electrochemical anodizing operation of the silicon comprising contact with an acid, for example hydrofluoric acid, allows the storage of hydrogen at atmospheric pressure in the form of Si-H x bonds (x can take the values 1, 2 or 3).
• x can take the values 1, 2 or 3).
• the efficiency of this storage experimentally reaches the level of around 3 millimoles per cm 3 (for the nano-columns) without any optimization of the process.
• These values can theoretically be increased by a factor of 10, that is to say reach 30 millimoles per cm 3 , using nanoporous silicon (of the nano-sponge type). This is explained by the size of the nano-crystallites which is approximately 10 times smaller than that of the nano-crystallites of meso-porous silicon (with equivalent porosity).
• the particle size can be modified if the nanostructures are treated by physicochemical means before grinding.
• the hydrogen storage capacity is then improved by a factor 1 + 2 (1-P) 2 where P is the initial porosity.
• P is the initial porosity.
• Table I groups the theoretical performances of the hydrogen tank according to the invention as a function of the nanostructures derived from porous silicon.
• Table II compares the theoretical performances of the hydrogen tank according to the invention as a function of the nanostructures derived from porous silicon used with respect to the storage means of the known art in the fuel cell application.
• the extraction of hydrogen from the tank according to the invention can be obtained by a heat treatment of the tank or a chemical treatment (for example with ethanol). It can also be obtained by applying radiation (for example ultraviolet), an electric field or mechanical energy (for example compression).
• the hydrogen tank according to the invention can be recharged by a simple contact with an acid. To give an order of magnitude of the mass production potentials, it is estimated that about fifty silicon wafers 30 cm in diameter, 500 ⁇ m thick, should be anodized to obtain 1 kg of porous silicon nanostructures. . This is easily achievable in the industrial environment.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Electrochemistry (AREA)
• Inorganic Chemistry (AREA)
• Sustainable Development (AREA)
• Manufacturing & Machinery (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Energy (AREA)
• Combustion & Propulsion (AREA)
• General Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Hydrogen, Water And Hydrids (AREA)
• Fuel Cell (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)
• Silicon Compounds (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Related Child Applications (1)

Publications (2)

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Family Applications (1)

Country Status (9)

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Family Cites Families (8)

• 2003
  • 2003-07-28 FR FR0350375A patent/FR2858313B1/fr not_active Expired - Fee Related
• 2004
  • 2004-07-27 ES ES04767919T patent/ES2305839T3/es not_active Expired - Lifetime
  • 2004-07-27 WO PCT/FR2004/050358 patent/WO2005012163A2/fr not_active Ceased
  • 2004-07-27 EP EP04767919A patent/EP1648815B1/fr not_active Expired - Lifetime
  • 2004-07-27 DE DE602004013328T patent/DE602004013328T2/de not_active Expired - Lifetime
  • 2004-07-27 DK DK04767919T patent/DK1648815T3/da active
  • 2004-07-27 JP JP2006521636A patent/JP5079328B2/ja not_active Expired - Fee Related
  • 2004-07-27 AT AT04767919T patent/ATE393117T1/de not_active IP Right Cessation
  • 2004-07-27 US US10/566,041 patent/US20070059859A1/en not_active Abandoned
• 2010
  • 2010-11-19 US US12/950,211 patent/US20110070142A1/en not_active Abandoned

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