| Patent application number | Description | Published |
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| 20080220282 | Highly conductive, multi-layer composite precursor composition to fuel cell flow field plate or bipolar plate - This invention provides a moldable, multiple-layer composite composition, which is a precursor to an electrically conductive composite flow field plate or bipolar plate. In one preferred embodiment, the composition comprises a plurality of conductive sheets and a plurality of mixture layers of a curable resin and conductive fillers, wherein (A) each conductive sheet is attached to at least one resin-filler mixture layer; (B) at least one of the conductive sheets comprises flexible graphite; and (C) at least one resin-filler mixture layer comprises a thermosetting resin and conductive fillers with the fillers being present in a sufficient quantity to render the resulting flow field plate or bipolar plate electrically conductive with a conductivity no less than 100 S/cm and thickness-direction areal conductivity no less than 200 S/cm | 09-11-2008 |
| 20080248275 | Nano-scaled graphene plate films and articles - Disclosed is a nano-scaled graphene article comprising a non-woven aggregate of nano-scaled graphene platelets wherein each of the platelets comprises a graphene sheet or multiple graphene sheets and the platelets have a thickness no greater than 100 nm (preferably smaller than 10 nm) and platelets contact other platelets to define a plurality of conductive pathways along the article. The article has an exceptional thermal conductivity (typically greater than 500 Wm | 10-09-2008 |
| 20080258359 | Low-temperature method of producing nano-scaled graphene platelets and their nanocomposites - A method of exfoliating a layered material to produce separated nano-scaled platelets having a thickness smaller than 100 nm. The method comprises: (a) providing a graphite intercalation compound comprising a layered graphite containing expandable species residing in an interlayer space of the layered graphite; (b) exposing the graphite intercalation compound to an exfoliation temperature lower than 650° C. for a duration of time sufficient to at least partially exfoliate the layered graphite without incurring a significant level of oxidation; and (c) subjecting the at least partially exfoliated graphite to a mechanical shearing treatment to produce separated platelets. The method can further include a step of dispersing the platelets in a polymer or monomer solution or suspension as a precursor step to nanocomposite fabrication. | 10-23-2008 |
| 20080268318 | Carbon cladded composite flow field plate, bipolar plate and fuel cell - The present invention provides a carbon-cladded composite composition for use as a fuel cell flow field plate or bipolar plate. In one preferred embodiment, the composition comprises a core composite layer sandwiched between two clad layers, wherein (a) the clad layer comprises a conductive carbon or graphite material (e.g., carbon nano-tubes, nano-scaled graphene plates, graphitic nano-fibers, and fine graphite particles); (b) the core composite layer comprises a matrix resin and a conductive filler present in a sufficient quantity to render the composite layer electrically conductive with an electrical conductivity no less than 1 S/cm (preferably no less than 100 S/cm); and (c) the composition has a planar outer surface on each clad side having formed therein a fluid flow channel. | 10-30-2008 |
| 20080277628 | Exfoliated graphite composite compositions for fuel cell flow field plates - This invention provides an electrically conductive, less anisotropic, and structurally sound composite composition for fuel cell flow field plate or bipolar plate applications. The composition comprises: (a) expanded or exfoliated graphite; (b) particles of non-expandable graphite or carbon, wherein the particles are between 3% and 60% by weight based on the total weight of the particles and the expanded graphite; and (c) a binder or matrix material to bond the expanded graphite and the particles of non-expanded graphite or carbon for forming a highly conductive composite, wherein the binder or matrix material is between 3% and 60% by weight based on the total composite composition weight. The composite plate exhibits a thickness-direction conductivity typically greater than 35 S/cm, more typically greater than 50 S/cm, most typically greater than 100 S/cm, and a thickness-direction specific areal conductivity greater than 200 S/cm | 11-13-2008 |
| 20080279710 | Method of producing exfoliated graphite composite compositions for fuel cell flow field plates - A method of producing an electrically conductive composite composition, which is particularly useful for fuel cell bipolar plate applications. The method comprises: (a) providing a supply of expandable graphite powder; (b) providing a supply of a non-expandable powder component comprising a binder or matrix material; (c) blending the expandable graphite with the non-expandable powder component to form a powder mixture wherein the non-expandable powder component is in the amount of between 3% and 60% by weight based on the total weight of the powder mixture; (d) exposing the powder mixture to a temperature sufficient for exfoliating the expandable graphite to obtain a compressible mixture comprising expanded graphite worms and the non-expandable component; (e) compressing the compressible mixture at a pressure within the range of from about 5 psi to about 50,000 psi in predetermined directions into predetermined forms of cohered graphite composite compact; and (f) treating the so-formed cohered graphite composite to activate the binder or matrix material thereby promoting adhesion within the compact to produce the desired composite composition. Preferably, the non-expandable powder component further comprises an isotropy-promoting agent such as non-expandable graphite particles. Further preferably, step (e) comprises compressing the mixture in at least two directions. The method leads to composite plates with exceptionally high thickness-direction electrical conductivity. | 11-13-2008 |
| 20080279756 | Method of producing exfoliated graphite, flexible graphite, and nano-scaled graphene platelets - The present invention provides a method of exfoliating a layered material (e.g., graphite and graphite oxide) to produce nano-scaled platelets having a thickness smaller than 100 nm, typically smaller than 10 nm. The method comprises (a) dispersing particles of graphite, graphite oxide, or a non-graphite laminar compound in a liquid medium containing therein a surfactant or dispersing agent to obtain a stable suspension or slurry; and (b) exposing the suspension or slurry to ultrasonic waves at an energy level for a sufficient length of time to produce separated nano-scaled platelets. The nano-scaled platelets are candidate reinforcement fillers for polymer nanocomposites. Nano-scaled graphene platelets are much lower-cost alternatives to carbon nano-tubes or carbon nano-fibers. | 11-13-2008 |
| 20080299419 | Laminated exfoliated graphite composite-metal compositions for fuel cell flow field plate or bipolar plate applications - An electrically conductive laminate composition for fuel cell flow field plate or bipolar plate applications. The laminate composition comprises at least a thin metal sheet having two opposed exterior surfaces and a first exfoliated graphite composite sheet bonded to the first of the two exterior surfaces of the metal sheet wherein the exfoliated graphite composite sheet comprises: (a) expanded or exfoliated graphite and (b) a binder or matrix material to bond the expanded graphite for forming a cohered sheet, wherein the binder or matrix material is between 3% and 60% by weight based on the total weight of the first exfoliated graphite composite sheet. Preferably, the first exfoliated graphite composite sheet further comprises particles of non-expandable graphite or carbon in the amount of between 3% and 60% by weight based on the total weight of the non-expandable particles and the expanded graphite. Further preferably, the laminate comprises a second exfoliated graphite composite sheet bonded to the second surface of the metal sheet to form a three-layer laminate. Surface flow channels and other desired geometric features can be built onto the exterior surfaces of the laminate to form a flow field plate or bipolar plate. The resulting laminate has an exceptionally high thickness-direction conductivity and excellent resistance to gas permeation. | 12-04-2008 |
| 20090047579 | Carbon anode compositions for lithium ion batteries - A lithium secondary battery comprising a positive electrode, a negative electrode comprising a carbonaceous material which is capable of absorbing and desorbing lithium ions, and a non-aqueous electrolyte disposed between the negative electrode and the positive electrode. The carbonaceous material comprises a graphite crystal structure having an interplanar spacing d | 02-19-2009 |
| 20090057940 | Method of producing less anisotropic flexible graphite - This invention provides a method for recompressing expanded or exfoliated graphite to produce a less anisotropic, flexible graphite foil having a thickness-direction electrical conductivity no less than 15 S/cm. In one preferred embodiment, the method comprises: (a) providing a mixture of expanded or exfoliated graphite flakes and particles of non-expandable graphite or carbon, wherein the non-expandable graphite or carbon particles are in the amount of between about 3% and 70% by weight based on the total weight of the particles and the exfoliated graphite; (b) compressing the mixture in at least a first direction to a pressure within the range of from about 0.04 MPa to about 350 MPa into a first cohered mixture; and (c) compressing this first cohered mixture in a second direction, different from the first direction, to a pressure sufficient to produce said flexible graphite foil having a bulk density within the range of from about 0.1 g/cm | 03-05-2009 |
| 20090061191 | Recompressed exfoliated graphite articles - This invention provides an electrically conductive, less anisotropic, recompressed exfoliated graphite article comprising a mixture of (a) expanded or exfoliated graphite flakes; and (b) particles of non-expandable graphite or carbon, wherein the non-expandable graphite or carbon particles are in the amount of between about 3% and about 70% by weight based on the total weight of the particles and the expanded graphite flakes combined; wherein the mixture is compressed to form the article having an apparent bulk density of from about 0.1 g/cm | 03-05-2009 |
| 20090151847 | Process for producing laminated exfoliated graphite composite-metal compositions for fuel cell bipolar plate applications - A process for producing an electrically conductive laminate composition for fuel cell flow field plate or bipolar plate applications. The process comprises: (a) feeding a thin metal sheet, having a first surface and a second surface, into a consolidating zone; and (b) feeding a first exfoliated graphite composite sheet onto the first surface of the metal sheet to form a two-layer precursor laminate in this consolidating zone; wherein the exfoliated graphite composite sheet comprises (i) expanded or exfoliated graphite and (ii) a binder or matrix material to bond the expanded graphite to form a cohered. The process preferably further comprises (c) feeding a second exfoliated graphite composite sheet onto the second surface of the metal sheet to form a three-layer precursor laminate. Both the first and second exfoliated graphite composite sheet may further comprise particles of non-expandable graphite or carbon in the amount of between 3% and 60% by weight based on the total weight of the non-expandable particles and the expanded graphite. Surface flow channels and other desired geometric features can be built onto the exterior surfaces of the laminate to form a flow field plate or bipolar plate by a procedure such as in-line embossing or molding. The resulting laminate has an exceptionally high thickness-direction conductivity and excellent resistance to gas permeation. | 06-18-2009 |
| 20090155578 | Nano-scaled graphene platelets with a high length-to-width aspect ratio - This invention provides a nano-scaled graphene platelet (NGP) having a thickness no greater than 100 nm and a length-to-width ratio no less than 3 (preferably greater than 10). The NGP with a high length-to-width ratio can be prepared by using a method comprising (a) intercalating a carbon fiber or graphite fiber with an intercalate to form an intercalated fiber; (b) exfoliating the intercalated fiber to obtain an exfoliated fiber comprising graphene sheets or flakes; and (c) separating the graphene sheets or flakes to obtain nano-scaled graphene platelets. The invention also provides a nanocomposite material comprising an NGP with a high length-to-width ratio. Such a nanocomposite can become electrically conductive with a small weight fraction of NGPs. Conductive composites are particularly useful for shielding of sensitive electronic equipment against electromagnetic interference (EMI) or radio frequency interference (RFI), and for electrostatic charge dissipation. | 06-18-2009 |
| 20090169467 | Production of ultra-thin nano-scaled graphene platelets from meso-carbon micro-beads - A method of producing nano-scaled graphene platelets (NGPs) having an average thickness no greater than 50 nm, typically less than 2 nm, and, in many cases, no greater than 1 nm. The method comprises (a) intercalating a supply of meso-carbon microbeads (MCMBs) to produce intercalated MCMBs; and (b) exfoliating the intercalated MCMBs at a temperature and a pressure for a sufficient period of time to produce the desired NGPs. Optionally, the exfoliated product may be subjected to a mechanical shearing treatment, such as air milling, air jet milling, ball milling, pressurized fluid milling, rotating-blade grinding, or ultrasonicating. The NGPs are excellent reinforcement fillers for a range of matrix materials to produce nanocomposites. Nano-scaled graphene platelets are much lower-cost alternatives to carbon nano-tubes or carbon nano-fibers. | 07-02-2009 |
| 20100092723 | NANO-SCALED GRAPHENE PLATE-REINFORCED COMPOSITE MATERIALS AND METHOD OF PRODUCING SAME - Disclosed are a nano-composite composition and a method of making such a composite that is composed of a matrix material and dispersed reinforcement nano-scaled graphene plates (NGPs) that are substantially aligned along at least one specified direction or axis. The method comprises: (a) providing a mixture of nano-scaled graphene plates (NGPs) and a matrix material in a fluent state; (b) extruding the mixture to form a filament wherein NGPs are aligned along a filament axis; (c) aligning a plurality of segments of the filament in a first direction, or moving the filament back and forth along a first direction and its opposite direction, to form a NGP-matrix filament preform; and (d) consolidating the preform to form the nanocomposite material. Also disclosed is a method of making a nano-composite fiber. | 04-15-2010 |
| 20100222482 | MASS PRODUCTION OF NANO-SCALED PLATELETS AND PRODUCTS - Disclosed is a process for exfoliating a layered material to produce nano-scaled platelets having a thickness smaller than 100 nm, typically smaller than 10 nm, and often between 0.34 nm and 1.02 nm. The process comprises: (a) charging a layered material to an intercalation chamber comprising a gaseous environment at a first temperature and a first pressure sufficient to cause gas species to penetrate into the interstitial space between layers of the layered material, forming a gas-intercalated layered material; and (b) operating a discharge valve to rapidly eject the gas-intercalated layered material through a nozzle into an exfoliation zone at a second pressure and a second temperature, allowing gas species residing in the interstitial space to exfoliate the layered material to produce the platelets. The gaseous environment preferably contains only environmentally benign gases that are reactive (e.g., oxygen) or non-reactive (e.g., noble gases) with the layered material. The process can additionally include dispersing the platelets in a matrix material to form a nanocomposite. The process also can include an additional process of re-compressing the nana-scaled platelets into a product such as a flexible graphite sheet. | 09-02-2010 |
