JP2015516643A - Nanostructured composite battery and method for producing nanostructured composite battery from nanostructured composite sheet - Google Patents

Abstract

A secondary battery that can be charged after discharging is provided. The battery includes a positive electrode made from a sheet of carbon nanotubes infiltrated with a mixed metal oxide and a negative electrode made from a sheet of carbon nanotubes comprising silicon or germanium particles. [Selection] Figure 12

Description

<Related applications>
This application claims priority to US Provisional Patent Application No. 61 / 051,249, filed May 7, 2008, which is prior to US Patent Application No. 12 / 437,538, filed May 7, 2009. US patent application Ser. No. 13 / 367,572, filed Feb. 7, 2012, which is a part continuation, each of which is hereby incorporated by reference in its entirety.

<Technical field>
The present invention relates to a battery, and more specifically, to a secondary battery using a sheet of non-woven carbon nanotubes.

  Carbon nanotubes are known to have extraordinary tensile strength, including high load against failure and relatively high tensile modulus. Carbon nanotubes can also be very resistant to fatigue, radiation damage, and heat. For this purpose, the addition of carbon nanotubes to the composite material can increase the tensile strength and rigidity of the composite material.

  Within the last 15 years, interest in carbon nanotubes has increased significantly both within and outside the research community due to a better understanding of the properties of carbon nanotubes. One important point for using these properties is to synthesize them in an amount sufficient to widely deploy the nanotubes. For example, large quantities of carbon nanotubes may be required if large quantities of carbon nanotubes have to be used as a high-strength kouseiouso in a composite with a macroscopic scale structure (ie, a structure having dimensions greater than 1 cm).

  One common route for nanotube synthesis may be through the use of gas phase pyrolysis, such as that used in connection with chemical vapor deposition. In this process, the nanotubes can be formed from the surface of the catalytic nanoparticles. Specifically, the catalyst nanoparticles can be exposed to a gas mixture that includes a carbon compound that serves as a feed for the production of nanotubes from the surface of the catalyst particles.

  In recent years, one promising route for the production of high capacity nanotubes has been to use chemical vapor deposition systems that augment nanotubes from “floating” catalyst particles in the reaction gas. Such systems typically pass a mixture of reaction gases through a heated chamber in which nanotubes can be generated from catalyst particles condensed from the reaction gas. Numerous other variations may be possible, including those where the catalyst particles may be pre-fed.

  However, if a large amount of carbon nanotubes can be produced, the nanotubes can adhere to the walls of the reaction chamber and consequently prevent nanomaterials from exiting the chamber. In addition, these disturbances can cause a pressure increase in the reaction chamber, resulting in a change in the kinetics of the overall reaction. The change in kinetics can lead to a decrease in the uniformity of the fabricated material.

  A further concern with nanomaterials is that the dangers associated with nanoscale materials are not yet fully understood, so that nanomaterials need to be handled and processed without producing large amounts of airborne particulates. ,That's what it means.

  The processing of nanotubes or nanoscale materials for macroscopic applications has steadily increased in recent years. The use of nanoscale materials and related materials in textile fibers is also increasing. In the textile field, fibers that are fixed length and processed in large quantities are sometimes referred to as staple fibers. Methods for dealing with staple fibers such as flax, wool and cotton have long been established. In order to use staple fibers in fabrics or other structural elements, staple fibers can be first formed into a bulk structure such as knitting yarn, hemp or sheet, which can then be processed into suitable materials. .

  Accordingly, it is desirable to provide a material that can take advantage of the characteristics and properties of carbon nanotubes so that the carbon nanotube sheets can be processed for end use applications such as batteries.

  The present invention, according to one embodiment, comprises a negative electrode comprising an anode current collector having at least one sheet of carbon nanotubes with semiconductor particles, a cathode current collection having at least one sheet of carbon nanotubes infiltrated with a mixed metal oxide. A battery is provided that includes a positive electrode including the device and a separator positioned between the negative electrode and the positive electrode. The battery further includes a case made from the carbon nanotube composite material. In one embodiment, the composite material may include carbon nanotubes and polyamides, polyphenylene sulfide, polyether ether ketone, polypropylene, bispolyamide, bismaleimide, epoxy, or combinations thereof.

The carbon nanotube sheet can be made from single-walled carbon nanotubes or multi-walled carbon nanotubes. The sheet of carbon nanotubes can have a density of about 80 g / m ² . The sheet of carbon nanotubes can include substantially aligned carbon nanotubes and can further include lithium as an intercalation compound.

  According to one embodiment, the anode includes semiconductor particles, such as silicon or germanium particles. Silicon or germanium particles can be ultrasonically welded to the carbon nanotubes. In one embodiment, the cathode includes a sheet of carbon nanotubes infiltrated with lithium mixed metal oxide comprising lithium, nickel, cobalt, or mixtures thereof, or alternatively infiltrated with zinc nickel oxide. . The separator may be a porous polyethylene membrane, a polyethylene membrane, or a combination thereof.

  The present invention also provides a method of forming an anode. The method forms a substantially planar body defined by a matrix of carbon nanotubes in the presence of semiconductor particles so as to allow formation of a carbon nanotube sheet with semiconductor particles throughout the matrix of nanotubes. Generating. In one embodiment, intercalation compounds such as lithium can be dispersed within the sheet during sheet formation or can be infiltrated into the sheet after sheet formation. Many mixtures can then be deposited on the surface to form a generally planar body defined by a matrix of carbon nanotubes with semiconductor particles interdispersed within the nanotube matrix. In some embodiments, large quantities of carbon nanotubes are formed, and the semiconductor particles are introduced into the bulk mixture to form a bulk mixture of carbon nanotubes and semiconductor particles. In some embodiments, lithium can be mixed with a volatile carrier in a volume, and the volatile carrier can evaporate in a hot environment to form a carbon nanotube composite sheet. In some embodiments, the sheet is exposed to an ultrasonic pulse train in the presence of silicon or germanium particles.

  The present invention also provides a method of forming a cathode. The method includes generating a substantially planar body defined by a matrix of carbon nanotubes in the presence of a lithium mixed metal oxide. Lithium mixed metal oxides can include lithium and nickel, cobalt, or mixtures thereof. In one embodiment, the mixed metal oxide can be incorporated during sheet formation, or alternatively can be sprayed onto the subsequently formed sheet. In some embodiments, large quantities of carbon nanotubes are formed and the mixed metal oxide is introduced into the large volume mixture to form a large volume mixture of carbon nanotubes and mixed metal oxides. Many mixtures can then be deposited on the surface to form a generally planar body defined by a matrix of carbon nanotubes with mixed metals mixed within the matrix of nanotubes. In some embodiments, the lithium mixed metal oxide can be mixed with a volatile support in volume, and the volatile support can evaporate in a hot environment to form a carbon nanotube composite sheet. It is.

  The present invention also provides a method of forming a battery. The method includes incorporating a plurality of semiconductor particles into a sheet of carbon nanotubes to form a negative electrode; infiltrating a lithium mixed metal oxide into a second sheet of carbon nanotubes to form a positive electrode; positive electrode and negative electrode And a step of sealing the positive electrode, the negative electrode, and the separator on the carbon nanotube sheet soaked with the polymer. In some embodiments, the sheet is made from aligned single-walled carbon nanotubes or multi-walled carbon nanotubes.

Fig. 3 illustrates the electrical properties of carbon nanotubes made according to one embodiment of the present invention. Fig. 4 illustrates resistivity versus temperature characteristics of carbon nanotubes made according to one embodiment of the present invention. 2 illustrates the resistivity versus temperature characteristics of carbon nanotubes in the presence (or absence) of a magnetic field. 2 illustrates a sheet of nanotubes according to one embodiment of the present invention. 3 illustrates an alternative embodiment of the present invention. Figure 3 illustrates a chemical vapor deposition system for assembling nanotubes, according to one embodiment of the present invention. 1 illustrates a system of the present invention for the formation and collection of nanofiber materials. 1 illustrates a system of the present invention for the formation and collection of nanofiber materials. 1 illustrates a system of the present invention for processing a nanostructured sheet after formation. Fig. 4 illustrates insertion loss from a nanostructured sheet made in accordance with one embodiment of the present invention. 2 illustrates a nanofiber nonwoven sheet made from the system shown in FIGS. 1-2, and from a system where the anode and cathode of the battery can be assembled according to one embodiment of the present invention. FIG. 4 illustrates a cross-sectional view of a matrix of nanotubes according to one embodiment of the present invention. Illustrates prior art battery technology. Fig. 4 illustrates a battery using a sheet of carbon nanotubes according to one embodiment. It is an image of a powder of micro silicon particles inserted into a carbon nanotube (CNT) conductive sheet. 3 is an image of nano-silicon particles “welded” to a carbon nanotube matrix. 2 is a graph showing specific conductivity as a function of frequency. It is a graph which shows the stress distortion with respect to a carbon nanotube composite material.

  The present invention, in one embodiment, provides a composite material made from nanostructured sheets, for example, designed to promote increased conductivity. In one embodiment, the sheet can include a generally planar body. The planar body can be defined in one embodiment by a matrix of nanotubes. A matrix is a lattice-like or network-like structure with openings between adjacent nanotubes, as defined herein. Because openings can exist between adjacent nanotubes in the matrix, protonated agents can be applied to enhance contact between the nanotubes for better conduction. To the desired degree, multiple composite sheets can then be layered together to enhance the thickness of the sheets.

  Currently, there are multiple processes and variations thereof to increase nanotubes and to form knitted yarn, sheet, or cable structures made from these nanotubes. These include: (1) chemical vapor deposition (CVD), a common process that can occur near ambient or at high pressure and at temperatures in excess of 400 ° C., (2) arc discharge, ie High temperature processes that can occur in tubes with a high degree of integrity, and (3) laser ablation.

  The present invention, in one embodiment, utilizes a CVD process or similar gas phase pyrolysis procedure known in the industry once the appropriate nanostructures comprising carbon nanotubes have been generated. Growth temperatures for CVD processes can be relatively low, for example ranging from 400 ° C to 1350 ° C. Both carbon nanotubes (CNT), single-walled (SWNT), or multi-walled (MWNT) are nanoscaled in one embodiment of the invention in the presence of a reagent carbon-containing gas (ie, a gaseous carbon source). It can be enlarged by exposing the catalyst particles. In particular, nanoscale catalyst particles can be introduced into the reagent carbon-containing gas either by addition of existing particles or by in situ synthesis of particles from organometallic precursors or non-metallic catalysts. Although both SWNTs and MWNTs can expand, in certain instances, SWNTs can be selected because of their relatively higher expansion rate and because of their tendency to form rope-like structures, May provide advantages in thermal conductivity, electronic properties, and strength.

  The strength of the individual carbon nanotubes produced in connection with the present invention may be about 30 GPa or more. Intensity is sensitive to defects as it should be noted. However, the elastic modulus of the carbon nanotubes made in the present invention is not sensitive to defects and can vary from about 1 to about 1.2 TPa. In addition, the load on breakage of these nanotubes can generally be a structure sensitive parameter and can range from about 10% up to about 25% in the present invention.

  Furthermore, the nanotubes of the present invention can be provided with a relatively small diameter. In embodiments of the present invention, nanotubes made in the present invention may be provided with diameters ranging from less than 1 nm to 10 nm. It should be understood that carbon nanotubes made in accordance with one embodiment of the present invention can be extended in length (ie, long tubes) when compared to commercially available carbon nanotubes. In embodiments of the present invention, the nanotubes made in the present invention may be provided with a length in the millimeter (mm) range.

The nanotubes of the present invention can also be used as conductive members for carrying relatively high currents, similar to litz wires or cables. However, unlike the litz wire or cable joined to the connector portion, the nanotube conductive member of the present invention may exhibit a relatively low impedance when compared. In particular, it has been observed in the present invention that nanotube-based wire cables or ribbons perform better compared to copper ribbons or litz wires as current pulses are shortened. One reason for the observed superior performance is that the effective frequency capacity of the pulse, which is about 100 ms to less than about 1 ms, can be calculated from the Fourier transform of the waveform for square and short current pulses. is there. Specifically, the individual carbon nanotubes of the present invention can function as conductive paths, and due to their small size, when the bulk structure is made from these nanotubes, the bulk structure can be, for example, about 10 ¹⁴ / cm. ^A very large number of conductive elements, ^two or more, can be included.

  The carbon nanotubes of the present invention can also demonstrate ballistic conduction as a fundamental means of conductivity. Thus, materials made from the nanotubes of the present invention can represent a significant advancement over copper and other metal conducting members under AC current conditions. However, in order to connect this type of conductive member to an external circuit, it is essential that each nanotube be brought into electrical or thermal contact in order to avoid contact resistance during connection.

  The carbon nanotubes of the present invention may exhibit the specific features shown in FIGS. 1-3. FIG. 1 illustrates the electrical properties of carbon nanotubes made in accordance with embodiments of the present invention. FIG. 2 illustrates the resistivity of these carbon nanotubes with respect to temperature. FIG. 3 illustrates the resistivity versus temperature characteristics of carbon nanotubes in the presence (and absence) of a magnetic field.

  It is noted throughout this application for nanotubes synthesized from carbon, but it should be noted that other compounds such as boron, MoS2, or combinations thereof may be used in the synthesis of nanotubes in accordance with the present invention. . For example, boron nanotubes can be increased, but it should be understood that the chemical precursors are different. In addition, it should be noted that boron may also be used to reduce the resistivity to individual carbon nanotubes. In addition, other methods such as plasma CVD can also be used to make the nanotubes of the present invention.

  The present invention, in one embodiment, provides a composite material made from a nanostructured composite sheet designed to increase the conductivity of carbon nanotubes in the sheet. As shown in FIG. 4, the composite material (10) may include a generally planar body in the form of a composite sheet (12). The matrix of nanotubes (14) may define a planar body. Adjacent carbon in a planar body because there is an opening between adjacent carbon nanotubes to allow efficient conduction between the nanoscale environment and conventional electrical and / or thermal circuit systems. The approach of the nanotubes can be closer to each other. In order to enhance the proximity between adjacent nanotubes, a protonated agent can be applied. In one embodiment, the composite material may be a single layer as shown in FIG. 4 or multiple layers on top of each other as shown in FIG.

<System for creating seats>
Referring now to FIG. 6, there is illustrated a system (30) similar to that disclosed in US Pat. No. 7,993,620 (incorporated herein by reference) used in the construction of nanotubes. Is done. The system (30) may in one embodiment lead to the synthesis chamber (31). The synthesis chamber (31) generally has an inlet end (311) that can be supplied with a reaction gas (ie, a gaseous carbon source), a hot zone (312) where synthesis of the extended length nanotube (313) can occur. ), And an outlet end (314) through which reaction products (ie, nanotubes and exhaust gases) can be collected. The synthesis chamber (31) may include a quartz tube (315) that extends through a furnace (316) in one embodiment. The nanotubes produced by the system (30) may on the other hand be individual single-walled nanotubes, bundles of such nanotubes, and / or entangled single-walled nanotubes. In particular, the system (30) is used in the formation of a substantially continuous nonwoven sheet produced from compressed and mixed nanotubes and having sufficient structural integrity to be treated as a sheet. obtain.

  The system (30) also includes a housing (in one embodiment of the invention) designed to be sufficiently sealed to minimize the release of airborne microparticles from the interior of the synthesis chamber (31) to the environment. 32) may also be included. The housing (32) may also act to prevent oxygen from entering the system (30) and reaching the synthesis chamber (31). In particular, the presence of oxygen in the synthesis chamber (31) can affect integrity and impair the production of nanotubes (313). The system (30) may also include an injector similar to that disclosed in patent application 12 / 140,263, which is incorporated herein by reference in its entirety.

  The system (30) includes a moving belt (320) located in a housing (32) designed to collect synthetic nanotubes (313) made from a CVD process in the synthesis chamber (31) of the system (30). ) May also be included. In particular, the belt (320) can be used to allow nanotubes to collect on the belt to later form an expandable structure (321) that is sufficiently continuous, eg, a sheet of nonwoven fabric. Such a sheet is a matrix of compressed, substantially unaligned and mixed nanotubes (313), bundles of nanotubes, or entangled with sufficient structural integrity to be treated as a sheet. Can be made from nanotubes.

  To collect the fabricated nanotubes (313), the belt (320) is adjacent to the outlet end (314) of the synthesis chamber (31) to allow the nanotubes to be placed on the belt (320). Can be positioned. In one embodiment, the belt (320) may be positioned substantially parallel to the gas flow from the outlet end (314), as shown in FIG. Alternatively, the belt (320) is positioned substantially perpendicular to the gas flow from the outlet end (314) and is in a nature to allow the gas flow carrying the nanomaterial to pass through it. It may be porous. The belt (320) can be designed as a continuous loop similar to a conventional conveyor belt. To that end, the belt (320), in one embodiment, can be looped to generally face the rotating element (322) (eg, a roller) and driven by a mechanical device such as an electric motor. Alternatively, the belt (320) may be a rigid cylinder. In one embodiment, the motor can be controlled through the use of a control system such as a computer or microprocessor, so that tension and speed can be optimized. The collected nanotubes can then be removed for later use, either manually or by any other means of removing the belt (320).

  To the extent desired, a pressure applicator such as a roller (45) can be used. Referring to FIG. 7, the application of pressure is located adjacent to a belt (44) that may be positioned substantially perpendicular to the gas flow to apply a compressive force (ie, pressure) on the collected nanomaterial. It may be. In particular, as the nanomaterial is carried toward the roller (45), the nanomaterial on the belt (44) may be forced to move under and against the roller (45), resulting in pressure Can be applied to the mixed nanomaterial, while the nanomaterial is compressed between a belt (44) and a roller (45), resulting in an agglomerated well-bonded sheet (46). To enhance the pressure on the nanomaterial on the belt (44), the plate (444) can be located behind the belt (44) to provide a hard surface to which pressure from the roller (45) can be applied. . If the collected nanomaterial is sufficient in quantity and fully integrated, the use of a roller (45) is not necessarily required, so that an appropriate number of contact sites produces a sheet (46) Note that it exists to provide the necessary cohesive strength.

  A scalpel or blade (47) may be provided downstream of the roller (45) to separate the mixed nanomaterial sheet (46) from the belt (44) for later removal from the housing (42), Its edge faces the surface (445) of the belt (44). Thus, as the sheet (46) moves downstream through the roller (45), the blade (47) may act to lift the sheet (46) from the surface (445) of the belt (44). In an alternative embodiment, the blade is not used to remove the seat (46). Correctly, removal of the sheet (46) may be manual or by other known methods in the art.

  In addition, a spool or roller (48) is provided downstream of the blade (47) so that the cut sheet (46) is later directed onto it and around the roller (48) for collection There is a case that you can get caught in. When the sheet (46) is wound around the roller (48), multiple layers may be formed. Of course, other mechanisms can be used as long as the sheet (46) can be subsequently collected for removal from the housing (42). Like the belt (44), the roller (48) may be driven by a mechanical drive, such as an electric motor (481), in one embodiment, so that its axis of rotation is approximately in the direction of movement of the seat (46). May be orthogonal.

  In order to minimize the bonding of the sheet (46) itself when wrapped around the roller (48), the separating material (49) (see FIG. 8) causes the sheet (46) to be wound around the roller (48). Before, it can be applied on one side of the sheet (46). The separation material (49) for use in connection with the present invention may be one of a variety of commercially available metal sheets or polymers that can be fed to a continuous roll (491). To that end, when the sheet (46) is wound around the roller (48), the separating material (49) can be pulled along the sheet (46) onto the roller (48). As long as it can be applied to one side of the sheet (46), the polymer comprising the separating material (49) can be provided in sheet, liquid, or any other form. Furthermore, since the mixed nanotubes in the sheet (46) can include nanoparticles of ferromagnetic catalyst such as Fe, Co, Ni, etc., the separation material (49) is in one embodiment the sheet ( In order to prevent 46) from sticking strongly to the separating material (49), it may be a non-magnetic material such as, for example, conductive or others. In alternative embodiments, a separation material may not be necessary.

  After the sheet (46) is generated, it remains as a sheet (46) or can be cut into small sections such as strips. In one embodiment, a laser may be used to cut the sheet (46) into strips. The laser beam, in one embodiment, may be located adjacent to the housing so that the laser is directed to the sheet (46) as it exits the housing. A computer or program for controlling the operation of the laser beam and the cutting of the strip can be utilized. In alternative embodiments, any mechanical means or other means known in the art for cutting the sheet (46) into strips may be used.

  To a desired degree, an electrostatic field (not shown) can be generated from the synthesis chamber (31) and can be used to align the nanotubes generally in the direction of belt motion. The electrostatic field can be generated in one embodiment, for example, by placing two or more electrodes around the exit end (314) of the synthesis chamber (31) and applying a high voltage to the electrodes. The voltage may vary from about 10 V to about 100 kV, preferably from about 4 kV to about 6 kV, in one embodiment. If necessary, the electrodes can be protected with an insulator, such as small quartz or other suitable insulator. The presence of an electric field can cause the nanotubes moving through it to be well matched to the electric field and provide alignment of the nanotubes after movement of the belt.

  Alternatively, the carbon nanotubes are aligned by stretching after synthesis of the carbon nanotube sheet, as provided in co-pending US patent application Ser. No. 12 / 170,092, incorporated herein by reference in its entirety. Can be done.

  The system (30) can provide high strength bulk nanomaterials in a nonwoven sheet, such as the sheet illustrated in FIG. 11A, as described. Carbon nanotubes (14), in one embodiment, are deposited in multiple separate layers (51) to form a multi-layer structure or morphology in a single CNT sheet (12), as shown in FIG. 11B. obtain. As noted above, the nanofiber nonwoven sheet (110) can be made from the deposition of multiple separate layers of either SWNT or MWNT carbon nanotubes. In one embodiment, the tensile strength of such a nonwoven sheet (110) can be 40 MPa or more for SWNTs. Furthermore, such sheets can be used with the remaining catalyst from the formation of nanotubes. However, a typical residue may be less than 2 atomic percent.

  By providing nanomaterials on a nonwoven sheet, bulk nanomaterials can be easily handled and later processed for end use applications, including hydrogen storage, batteries, or capacitor components, among others.

  It should be understood that carbon nanotubes made in accordance with embodiments of the present invention may not require treatment with a surfactant and may be about 3 times better in conductivity and thermal conductivity. Furthermore, a carbon nanotube sheet made according to embodiments of the present invention can include multiple layers. On the other hand, for example, carbon nanotubes in bucky paper are made of relatively short nanotubes and require treatment with a surfactant. In addition, bucky paper is made from only one layer of nanotubes, as opposed to multiple layers provided with the nonwoven sheet of the present invention.

<Processing process>
Once the sheet (46) is produced to the desired degree, the sheet (46) may be subjected to processing to enhance the conductivity and / or productivity of the nanotubes in the sheet. Once the strip is generated, it may also be subjected to treatment to enhance the conductivity and / or productivity of the nanotubes in the strip.

  Processing of the formed sheet (46) includes, in one embodiment, exposing the sheet (46) to a protonated agent. One feature of the protonated agent may be to bring the carbon nanotubes closer together. By bringing the carbon nanotubes closer together, the protonated agent can act to reduce surface tension, reduce resistivity, and increase sheet conductivity. Examples of protonating agents include hydronium ions, hydrochloric acid, hydrobromic acid, hydrofluoric acid, hydroiodic acid, carbonic acid, sulfuric acid, nitric acid, fluorosulfuric acid, chlorosulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid , Acids such as oleum, agents thereof, or combinations thereof, or other materials that may be electrically and / or thermally conductive.

  The protonated agent may be applied in one embodiment by use of a device (60), such as that shown in FIG. The apparatus, in one embodiment, includes a plurality of rollers for guiding the sheet through the application process. As shown, the first roller (64) and the second roller (65) may be located adjacent to each other, and the second roller (65) may be placed below the roller (64). A tab (61) comprising a first end (62), a second end (63) and containing a protonated agent may be located directly below the first roller (64) and the second roller (65). . The first roller can act to pass the tab (61) and press the sheet onto the second roller (65). The second roller (65) can pull the sheet from the first roller (64) and squeeze excess protonated drug fluid from the sheet. A third roller (66) is placed on the first end (62) of the tab near the first roller (64), while a fourth roller (67) is near the second roller (65). Can be placed over the second end (63) of the tab. The rollers (64, 65, 66, and 67) can be positioned sequentially to allow the sheet (68) to move smoothly through the rollers. Of course, four rollers are shown in FIG. 9, but the apparatus for post-processing the sheet (68) may include a few or many rollers. To the extent necessary, the hood can be positioned in a manner that prevents leakage of vapor from the protonated drug. In one embodiment, the device (60) may include a hood such as a polypropylene hood.

  Treatment of the sheet (68) with the protonated agent may include placing a bobbin or roll of sheet (68) on the third roller (66). Thereafter, the sheet (68) moves downstream, from the third roller (66), through the first roller (64), into the tab (61) containing the protonated drug, and on the second roller (65). And cross the fourth roller (67).

  In certain situations after processing, the resulting sheet (68) may be acidic or basic. A rinsing liquid can be applied to the sheet (68) to make the pH of the resulting sheet (68) approximately neutral. The rinse may be applied with the protonated agent in one embodiment or separately from the protonated agent.

  In another embodiment, the processing of the sheet (68) may further comprise spraying the second solution onto the sheet (68) such that the sheet (68) exits the furnace and is collected on the belt (320). The solution may, in one embodiment, contain a mixture of compounds that coat the outer surface of the nanotubes in a manner that enhances the alignment of the carbon nanotubes and allows the carbon nanotubes to be closer together.

  In one embodiment, the mixture of the second solution can include a solvent, a polymer, a metal, or a combination thereof. The solvent used with the solution of the present invention can be used to smooth the sheet to obtain better alignment and enhanced properties of the carbon nanotubes. Examples of solvents that can be used for the solution include toluene, kerosene, benzene, hexane, any alcohol (including but not limited to ethanol, methanol, butanol, isopropanol), as well as tetrahydrofuran, 1-methyl-2- It includes pyrrolidinone, dimethylformamide, methylene chloride, acetone, or any other solvent that is intended to not limit the invention in this manner. In one embodiment, the solvent can be used as a support for polymers, monomers, inorganic salts, or metal oxides.

  Examples of polymers that can be used for the solution include polyurethane, polyethylene, poly (styrene butadiene), polychloroprene, poly (vinyl alcohol), poly (vinyl pyrrolidone), poly (acrylonitrile-co-butadiene-co-styrene), Small molecule or polymer matrix including but not limited to epoxy, polyureasilazane, bismaleimide, polyamide, polyimide, polycarbonate, or any monomer (including but not limited to styrene, divinylbenzene, methyl acrylate, and tert-butyl acrylate) (Thermosetting or thermoplastic). In one embodiment, the polymer may include polymer particles that are difficult to obtain in liquid form.

Examples of metals that can be used for the solution include, but are not limited to, salts (nickel hydroxide, cadmium hydroxide, nickel chloride, copper chloride, calcium zincate (CaZn ₂ (OH) ₆ ), any Transition metals, alkali metals, or alkaline earth metal salts, or mixtures thereof) or metal oxides (zinc oxide, iron oxide, silver oxide, copper oxide, manganese oxide, LiCoO ₂ , LiNiO ₂ , LiNixCol-xO _2). , Any transition metal, alkali metal, or alkaline earth metal oxide, or mixtures thereof, including but not limited to LiMn ₂ O ₄ . In one embodiment, the metal can include a polymer or volatile solvent to make a carbon nanotube metal matrix composite. Examples of such polymers or volatile solvents include powder forms of aluminum or its alloys, nickel, superalloys, copper, silver, tin, cobalt, iron, iron alloys, or binary composites and Included are any elements that can be produced in powder form, including the original alloy or even superconductor.

  A spray device can be used to disperse the solution. The spraying device may be any commercially available device. In one embodiment, at one end of the spray device there is a spray nozzle through which the solution can be sprayed onto the sheet (46). In one embodiment, the spray head may be flat, round, or any other shape that allows the solution to exit. To the extent desired, the spray nozzle may discharge the solution in a continuous or pre-programmed manner.

  Once the sheet (68) has been processed, the processed sheet (68) can be exposed to a heat source for processing of the sheet. For example, the sheet can be subjected to sintering, hot isostatic pressing, hot pressing, cold isostatic pressing to provide the desired form of the composite sheet or final product.

The processing of the composite sheet, in another embodiment, further includes injecting a glassy carbon material into the composite sheet to increase the structural integrity of the sheet and provide a sufficiently low resistance bond. . Glassy carbon may generally be in the form of carbon related to carbon nanotubes and may include many graphenes such as ribbons comprising a matrix of amorphous carbon. These ribbons include sp ² bonded ribbons that may be sufficiently similar to sp ² bonded nanotubes. As a result, they can have relatively good thermal and electrical conductivity. Examples of precursor materials from which glassy carbon can be made include furfuryl alcohol, RESOL resin (ie, alkylphenylformaldehyde), PVA, or liquid resin, or any material known to form glassy carbon upon heat treatment. included. Of course, other commercially available glassy carbon materials or precursor materials can be used.

  According to embodiments of the present invention, the carbon nanotube sheet can be chemically treated to allow substantial alignment of the carbon nanotubes within the sheet. The carbon nanotube sheet can be further processed to insert an active compound such as lithium or an inter-layer element, as described herein.

<Application of batteries>
A battery is generally a type of electrochemical battery that includes a pair of electrodes and an electrolyte disposed between the electrodes. One of the electrodes can be referred to as the cathode, where the active material is reduced during the discharge. The other electrode may be referred to as the anode, where another active material oxidizes during discharge. Secondary batteries are generally referred to as batteries that can charge electricity after discharge.

Due to the high voltage and high energy density of secondary batteries, research has been conducted on secondary batteries such as lithium secondary batteries. Special attention was paid to the electrode material for the cathode of the secondary battery. For example, US Pat. No. 4,833,048 discloses a rechargeable battery obtained by combining a disulfide compound with a metal M that supplies and traps cations (M ⁺ ). Rechargeable batteries provide an improved energy density of at least 150 Wh / kg. However, the difference between the oxidation potential and the reduction potential of the disulfide compound is very large. According to the theory of electrochemical reaction, electron transfer of disulfide compounds proceeds very slowly at room temperature. Therefore, it may be difficult to obtain a rechargeable battery that provides a higher current output of 1 mA / cm ² or higher at room temperature. The operation of batteries containing disulfide compound electrodes is limited to high temperatures in the range of 100 ° C. to 200 ° C., where electron transfer can proceed faster.

  The lithium-based chemistry offers significant energy storage promise; however, it is limited by the weight of mobile lithium that can be stored and burdened by extra weight. One metric of a device that generates power is power to weight ratio versus energy capacity. Conventional batteries, as well as currently available secondary batteries, are made from relatively heavy parts, so the amount of energy generated is not as efficient or ideal as if lighter materials could be used. In some cases.

  Lithium-based chemistry is almost ideal for the battery because the battery potential of 3 to 4.2 V provides a very high energy current source. Safety issues with lithium batteries are largely addressed by the use of lithium intercalation to graphite-based anodes as lithium reservoirs instead of pure lithium metal, and by adding appropriate thermal links and pressure relief. It was done. This approach, coupled with the use of shuttle compounds, has minimized safety issues associated with this chemistry. The remaining problems relate to the weight of various components, the possibility of thermal runaway, and external physical damage that results from accidents that can expose lithium to air or water.

  Existing battery technologies typically use metal current collectors that are covered with compounds including anode materials, cathode materials, and current enhancing additions such as graphite and binders. The anode current collector is typically copper, while the cathode current collector is typically aluminum and the case is typically steel. Occasionally sintered graphite plates are used as current collectors.

  The present invention, on the other hand, provides high power and high performance batteries (eg, rechargeable or secondary batteries) that utilize one or more sheets of carbon nanotubes for both the cathode and anode. The present invention also provides high power and high performance batteries for use in various energy and power related applications.

  The battery of the present invention generally includes a positive electrode, a negative electrode, a separator located between the electrodes, and a case. In some embodiments, the battery utilizes an electrode made from a carbon nanotube sheet for use as a current collector and may utilize a carbon nanotube composite case. In some embodiments, the electrodes utilize aligned carbon nanotube sheets that incorporate an active compound such as lithium or intercalation. According to one embodiment of the present invention, the battery may be a lithium ion battery. Alternatively, according to another embodiment of the present invention, the battery may be a nickel zinc battery.

  In electrochemical applications in this application, by using free-standing carbon nanotubes as electrodes, the electrodes remain bifunctional (ie, serve as both active materials and current collectors). Is possible. Since the binder does not require that these electrodes be made up, the potential for high temperature applications is considered, extending the use in battery applications beyond 200 ° C. (the temperature at which most conventional binders are unstable). Stand-alone electrodes also provide a lightweight and flexible geometry for thin film batteries and alternative form factors. The physical properties of independent CNT sheets are important considerations for any application, but for lithium ion batteries, the issues surrounding strength and conductivity are paramount. Since battery manufacture typically utilizes a roll coater or die cutting, strength is an important consideration for CNT electrodes due to the absence of binder and metal substrate. Although the synthesis and processing steps can dramatically affect this property, the typical SWCNT sheet made in accordance with embodiments of the present invention has a tensile strength of about 80-100 MPa. The Young's modulus for SWCNT sheets made according to embodiments of the present invention is in the range of about 5-10 GPa, indicating that large forces can be applied to these materials prior to plastic deformation. Another convenient property is that the CNT sheets of the present invention can be formed into any required form factor; they can be easily cut with conventional scissors.

The electrical conductivity of the purified SWCNT sheet of the present invention is about 10 ⁶ S / m, and can approach the electrical conductivity of a pure metal by appropriate doping. The temperature dependent reactions for the independent electrodes of the present invention also include conductivity reactions that have attractive electrical properties and exhibit less than about 3% variation in conductivity over the range of about 100-400K. . Electron transport in independent SWCNT electrodes made in accordance with embodiments of the present invention is due to dominant metal conduction that is interrupted by tunneling the barrier due to tube-to-tube interaction, as well as phonon scattering and variable This can be due to region hopping.

  The main structural elements of the battery of the present invention include (1) an anode current collector, (2) a cathode current collector, and (3) a structure case, all of which are CNT sheets and / or CNTs It can be made from a composite sheet. FIG. 13 illustrates one embodiment of a battery. The battery (50) includes a carbon nanotube cathode (52), a carbon nanotube anode (54), a separator (56) between the cathode and anode, and a case (58), as shown. The battery (50) also has an electrolyte material. During charging of the battery (50), ions (eg, lithium ions) move from the positive electrode (cathode) to the negative electrode (anode), while during discharge, ions move from the negative electrode to the positive electrode.

  The carbon nanotube composition of the present invention also minimizes the weight of the battery compared to existing batteries and increases the energy to weight ratio and / or the energy to volume ratio of the battery of the present invention. However, it can be useful.

  The stand-alone CNT electrode configuration eliminates the need for a metal foil substrate and can increase capacity and speed performance. Independent CNT electrodes store lithium and can support very high capacity semiconductor particles, such as silicon and germanium, which can significantly increase the specific capacity (Ah / kg) of anodes that can be used in batteries. .

  The battery of the present invention has an advantage that it does not have heavy materials such as an aluminum anode and a copper cathode, or a binder and a conductive filler. The carbon nanotube composition of the battery of the present invention can also provide high fracture toughness. In addition, the carbon nanotube battery of the present invention can prevent heat hot spots that can start to run away.

The anode and cathode may be formed from at least one sheet of carbon nanotubes in one embodiment. A sheet of carbon nanotubes can be made from a CVD process using the system (30) shown in FIG. Nanotubes produced in the gas phase using a floating catalytic CVD process can form large quantities of nanotubes that can be placed on a rotating drum. Compounds such as nickel, zinc, nickel zinc alloys, lithium, lithium mixed metal oxides, nickel zinc oxide, or combinations thereof can be added to form large quantities of nanotubes with compounds that can be deposited on a rotating drum. In order to create a wide mat defined by multiple layers of carbon nanotubes in a single sheet, the drum may be translated in front of the furnace outlet (see FIG. 11b). Referring to FIG. 5, multiple layers (12) of nanotubes (14) may be deposited to make a nonwoven sheet (20) to a desired density. In one embodiment, the density of the nonwoven sheet is about 1 mg / cm ² . In some embodiments, the density of each nonwoven sheet can be controlled within a wide range, for example from about 0.1 mg / cm ² to about 5 mg / cm ² . An example of such a nonwoven sheet is shown in FIG. 11a as item (110). Each sheet can be made in one embodiment by varying the thickness and / or number of layers of carbon nanotubes (14). In some embodiments, multiple sheets may be required to make up a carbon nanotube mat having a density of about 80 g / m ² . For example, multiple sheets can be layered on top of each other to provide the desired carbon nanotube density. To the extent desired, the sheet may or may not have a protonated agent.

<Cathode>
The cathode may in one embodiment be made from one or more sheets of aligned carbon nanotubes, eg, infiltrated with mixed metal oxides. According to embodiments, the mixed metal oxide may be nickel zinc oxide, nickel cobalt oxide, lithium metal oxide, or any other similar compound that is utilized for the generation of current. For example, the carbon nanotube sheet may include nanoscale iron-lithium-phosphate, lithium-nickel-oxide, lithium-cobalt-nickel-oxide, lithium-cobalt-oxide, zinc-nickel oxide, or May penetrate. Other substitutions may include lithium compounds with sulfur (for oxygen), sulfuric acid, borates, and silicates. Alternatively, the battery of the present invention may be zinc air based, sodium based, or lead acid based. It should be noted that although reference is made to aligned carbon nanotube sheets, non-aligned carbon nanotube sheets may also be used.

  The mixed metal oxide can be incorporated into the carbon nanotube sheet during construction of the carbon nanotube sheet used as the cathode. In some embodiments, the mixed metal oxide can be added during the nanotube growth process. For example, mixed metal oxides can be dispersed with many nanotubes during the nanotube growth process using any known method. In an alternative embodiment, the mixed metal oxide can be added or deposited after forming the carbon nanotube sheet using known methods. For example, the mixed metal oxide can be dispersed in a volatile carrier such as acetone, isopropanol, methanol, ethanol, and sprayed onto the carbon nanotube sheet. By heating the sheet and evaporating the carrier from the sheet, a composite material of carbon nanotube fine particles can be formed.

<Anode>
The anode of the battery of the present invention may include one or more carbon nanotube sheets incorporating a sheet of graphite particles, silicon particles, germanium particles, or a combination thereof. Alignment by including lithium intercalation compound or zinc-nickel alloy in its structure by adding lithium or zinc-nickel powder during the cathode-like growth process or by spraying pre-formed carbon nanotube sheet An anode can be formed from the finished CNT sheet. Note that although an aligned sheet of carbon nanotubes is mentioned, an unaligned sheet of carbon nanotubes may also be used.

  In one embodiment, silicon or germanium particles can be coated on a sheet of carbon nanotubes using a chemical vapor deposition process. For example, referring to FIGS. 14-15, a semiconductor powder such as silicon powder or germanium powder can be incorporated into the carbon nanotube sheet. Alternatively, a semiconductor powder, such as silicon powder or germanium powder, can be welded to the carbon nanotube sheet to form a negative current collector or anode. In some embodiments, the silicon particles can be dispersed in a solvent or carrier such as acetone, ethanol, methanol, and welded to the CNT sheet by a powerful ultrasonic pulse. In some embodiments, high energy welding or similar processes known in the art are used to add silicon or germanium particles to the carbon nanotubes so that the silicon particles are integrated with the carbon nanotubes. For example, silicon or germanium particles may be placed on top of one or more carbon nanotubes or on the surface of one or more carbon nanotubes. Alternatively, the silicon particles can be attached to the surface of the carbon nanotubes by any other suitable method known in the art.

  In some embodiments, the silicon or germanium particles are in the micrometer or nanometer range. In some embodiments, the silicon or germanium particles are 100 nm or less.

  By providing a carbon nanotube sheet with silicon or germanium nanoparticles inserted therein, it may not be necessary to add a binder or conductive additive to the anode. In addition, thermal stability can be improved to the point that the thermal sensor and vent valve can potentially be removed.

  An important point of using electrodes made from free-standing sheets of carbon nanotubes is that the usable capacity can be increased by removing the inert copper foil. The removal of the copper substrate has additional advantages including increased depth of discharge and the ability to maintain a nearly zero state of charge. It has been well documented that extended cycles below 2.5V result in copper substrate oxidation.

  In addition, the sheet of carbon nanotubes with silicon or germanium particles produced by the method used by the present invention has been found to have an energy density that is three times higher than that of a commercial graphite anode. (See Table 1).

  In one embodiment, 0.5 mg of nanosilicon particles was dispersed in 250 ml of acetone. Individual carbon nanotube sheets were placed in a metal holder so that they were suspended in the solution 0.25 to 0.50 inches away from an ultrasonic horn (Ultrasonicator VC600, Sonics & Materials, Newton). The ultrasonic horn was set to the following environment (duty cycle: 2 and microchip limit: 2.3). The duty cycle defined the percentage of time that a pulse was sent to the sample. The amplitude measured in microns is defined as the distance (trajectory) of the up and down movement that the probe tip moves. The amplitude set point defined the amount of energy transferred to the liquid based on the probe diameter. The timer was set to the target value and sonication was started. An ultrasonic horn was maintained in the center of the beaker to ensure that power was delivered evenly to the sample.

  Commercial graphite anodes with copper current collectors have an energy density of 350 mAh / g, while anodes with silicon deposited on SWNT current collector sheets have an energy of about 1500 mAh / g or more. Density can be provided. In addition to the above, the carbon nanotube sheet of the present invention has been found to have a capacitance that is at least 10 times higher than a commercially available anode.

<Separator>
In one embodiment, the positive and negative electrodes can be designed to be separated by a separator. For example, the separator can be a membrane such as a porous membrane and a hydrophilic membrane. In some embodiments, the separator can be a polypropylene and / or polyethylene electrolytic membrane. It will be contemplated that other thin separators / membranes may be placed between the electrodes, so long as the membrane allows diffusion of electrolyte therethrough. In one embodiment, the membrane may be a CELGARD ™ porous polyethylene membrane, or a polyethylene membrane, or a combination thereof, or any other membrane that can be used with alkaline batteries.

Any suitable electrolyte solution can be used. Typical electrolytes include, but are not limited to, KOH, HNO ₃ , HCl, tetraethylammonium bis (oxalato boric acid (TEABOB), tetraethylammonium tetrafluoroborate (TEABF ₄ ), or dissolved in acetonitrile And an aqueous solution of triethylmethylammonium tetrafluoroborate.

<Case>
In some embodiments, the battery case is made from a carbon nanotube polymer composite. The battery case can be formed from a pre-impregnated CNT sheet. These sheets can be impregnated with various polymer matrices such as reinforced epoxy, bismariamide, polypropylene, polyethylene, PPS, PEEK (polyetheretherketone), PTFE and the like. In some embodiments, the sheet can include a carbon nanotube content of about 20 to about 50%. The resulting composite density is less than 2 grams per cc compared to a density greater than 7.8 g / cc for the standard steel case.

  The bath for the sheet of carbon nanotubes can be riveted or spot welded. The latter is possible because, in one embodiment, the edges of the carbon nanotube sheet can be pre-plated with nickel.

  These battery cases can be produced separately in large quantities, or battery materials (anode, cathode, separator, inlet valve, outlet valve) can be encapsulated in a pre-impregnated state during the manufacturing process. . A case can be used to heat seal the battery anode, separator and cathode in one step. Alternatively, a thermoset matrix material can be used to completely seal the battery after assembly. If necessary, the safety pressure relief valve can be co-sealed to the structure simultaneously during assembly.

  Such composite materials have higher fracture strength than steel and are four times lighter in some embodiments. In addition, such a carbon nanotube composite material provides high fracture toughness to the case. Cases made from carbon nanotube composites have much stronger advantages than conventional cases made from steel, have high fracture toughness, and batteries to reduce crash damage Note that it can be used as a component.

  A comparison between an existing method and a battery according to one embodiment of the present invention is shown in FIGS. 12-13. In some embodiments, the anode is a mat having a plurality of carbon nanotube sheets on top of each other and including particles of silicon that have penetrated and are welded to the carbon nanotubes (FIG. 14).

  FIG. 16 shows that the specific conductivity was measured as a function of frequency for the copper collection device and the carbon nanotube collection device.

  FIG. 17 illustrates the stress strain curve of a 60% carbon nanotube epoxy composite. As shown, the carbon composite has a fracture stress of 1 Gpa.

<Battery pack>
In accordance with some embodiments of the present invention, the battery may be designed to optimize energy density and / or power. By increasing the number of cells in the battery pack, the battery can be designed to conserve a desired amount of energy. Thus, in one embodiment, the battery can be optimized to include two or more cells, each having the desired geometric shape and dimensions. For example, the cell may be cylindrical (wound in a spiral) or prismatic. The cell can be incorporated into a module or battery pack. As described herein, a cell or module can be placed in a case made from a carbon nanotube composite that has a much stronger advantage than that made from steel and has a high fracture toughness. And damage due to collision can be reduced.

  It will be contemplated that the carbon nanotube composite of the case may act as a heat sink. Thus, the battery design of the present invention having components as described can operate the battery without additional protection such as pressure sensors, temperature sensors, pressure release valves, or safety vents.

<Advantages and uses>
One of the disadvantages of metal hydride type batteries is that the integrity of the electrode is lost during multiple charging / discharging of the battery. This is because with the changing of the hydrating phase, there can be changes in the grid contacts that can lead to expansion leading to cracks in the alloy. Such alloys generally can withstand about 300-500 cycles until the battery begins to loosen its performance.

  On the other hand, when using nanostructured materials made by the method of the present invention, the number of cycles that the battery can withstand can be increased. In particular, batteries utilizing carbon nanotube sheets made in accordance with embodiments of the present invention can minimize this type of degradation and thus can withstand an unlimited number of charge and discharge cycles.

  It will be contemplated that carbon nanotube sheets not only can store much more energy than lithium ion batteries, but also have the advantage of not degrading during charge / discharge cycles. In addition, carbon nanotube sheets can provide a sufficiently large surface area, resulting in enormous energy that can be returned on demand when batteries with very high power and short peaks are required. Double layer charging can be adapted to hold. This reaction is a strong difference between the battery of the present invention and other commercially available secondary batteries.

The battery of the present invention comprising the components described above, including a sheet of conductive carbon nanotubes, has application as a secondary battery. A secondary battery is generally a battery that can be charged with electricity after discharging.
The battery design of the present invention can discharge the battery in two steps. In particular, the first discharge of the battery can generate a relatively high power and the second discharge can generate a relatively high energy.

  The carbon nanotubes of the present invention have various useful properties including high aspect ratio, channels for lithium ion intercalation, improved electrical and thermal conductivity, and increased capacity. . It should be noted that, similar to an anode having a sheet of SWCNT or MWCNT of the present invention, a cathode having a sheet of SWCNT or MWCNT of the present invention can exhibit improved electrical and thermal conductivity and capacity. In addition, cathodes and anodes made using the sheets of the present invention can exhibit weight loss. Furthermore, the use of the carbon nanotube sheet of the present invention can show an improvement in the power to weight ratio VS energy capacity.

  Note that the battery design can be optimized to reduce the mass and volume of the battery and to allow, for example, use in an electric vehicle. Sustainable energy systems that simultaneously reduce dependence on fossil fuel and greenhouse gas emissions are now being pursued worldwide. Underlying these efforts are strategies for developing more sustainable transportation (eg, electric vehicles) and the ability to increase the consumption of renewable energy from solar and wind technology. With such constant production and consumption requirements as described above, this direction requires enormous storage capacity that is expected to be realized effectively only with advanced batteries. Lithium ion technology has emerged as the best battery chemistry with an increase in energy density over other rechargeable technologies. However, ongoing technology demands require higher energy density, which may reduce features such as battery mass and volume for portable applications such as electric vehicles, mobile communications, and mobile grid storage. Absent. As battery-powered electric vehicles significantly reduce the use of foreign energy sources and greenhouse gas emissions, the improvement of lithium-ion batteries will directly support the Department of Advanced Research Projects (ARPA-E) mission area. I will.

<Other uses>
The systems and methods of the present invention can provide high strength, low weight, or similar weight of bulk nanomaterials in composite sheets. By providing nanomaterials to the composite sheet, bulk nanomaterials can be (i) structural systems such as fabrics, armor, composite reinforcements, antennas, conductors or heat conductors, heaters, and electrodes, (ii) Mechanical construction elements such as plates and eye beams, and (iii) easy to handle for end use applications including cables or ropes, which can then be processed. Other applications may include hydrogen storage or condenser components.

  The scale-up and commercialization of the aforementioned technology relies on the ability to produce large quantities of materials of sufficient quality at a price comparable to current lithium-ion battery carbon and substrates. A large sheet of high quality SWCNTS produced according to the method of the present invention provides a strong, lightweight, electrically and thermally conductive material from which batteries can be made.

  Further, the composite sheet may be incorporated into a composite structure for further end use applications such as sporting goods products, helmets, antennas, morphing applications, aerospace industry, lightning frame reinforcement processing. The composite sheet may also be free of nickel, which means it may be less toxic than standard products. Further, the composite sheet may be repairable to eliminate the need for complete or partial replacement. In one embodiment, the composite sheet is impregnated with a matrix precursor such as Krayton, vinyl ester, polyphenylene sulfide (PPS), polyetheretherketone (PEEK), bispolyamide, BMI (bismaleimide), epoxy, or polyamide. And then the matrix may be polymerized or thermally cured to form a composite material.

  The carbon nanotube composite sheets made from the present invention have a variety of uses. An example of a specific application is an electromagnetic interference shield (EMI shield) that can absorb, reflect, or transmit electromagnetic waves. The shield may be beneficial to prevent interference from surrounding equipment and may be found in stereo systems, phones, cell phones, televisions, medical devices, computers, and many other electrical products. For such and similar applications, the glassy carbon precursor is provided in a substantially thin layer, so that the penetration of the carbon nanotube sheet is minimized to prevent deterioration of the carbon nanotube sheet characteristics. It may be important to be able to.

  The EMI shield may also help to minimize insertion loss from the carbon nanotube sheet. The insertion loss represents the difference in power reception before and after using the composite sheet. As shown in FIG. 10, the power reception drops almost immediately and then stabilizes.

  The carbon nanotube composite sheet utilizes additional assemblies such as utilizing the resulting assembly in the absorption of radar signals (EMI shields), or to provide other desirable characteristics such as lightning protection, heat sinks, or actuators. Can have uses. For such applications, it may not be important whether the binder penetrates the carbon nanotube sheet. Thus, the glassy carbon material can be coated with less effort than is done in capacitor, battery, or fuel cell applications. In one embodiment, the substrate for use in this example can be a graphite epoxy, an e-glass epoxy, or a combination that includes other types of matrices.

  Although the present invention has been described with reference to particular embodiments, it will be appreciated by those skilled in the art that various changes and equivalents may be substituted without departing from the spirit and scope of the invention. It must be understood. In addition, many modifications may be made to adapt a particular situation, instruction, material and composition of matter, process steps, without departing from the spirit and scope of the present invention. All such modifications are intended to be within the scope of the claims appended hereto.

Claims (33)

A battery, the battery comprising:
A negative electrode comprising an anode current collector having at least one sheet of carbon nanotubes and semiconductor particles interdispersed within the sheet;
A battery comprising: a positive electrode comprising a cathode current collector having a sheet of at least one carbon nanotube infiltrated with a mixed metal oxide; and a separator positioned between the negative electrode and the positive electrode.   The battery of claim 1, wherein the sheet is made from single-walled carbon nanotubes.   The battery of claim 1, wherein the sheet is made from multi-walled carbon nanotubes.   The battery according to claim 1, wherein the semiconductor particles are silicon or germanium particles.   The battery according to claim 1, wherein the semiconductor particles are welded onto the carbon nanotubes.   The battery according to claim 1, wherein the positive electrode is made of a sheet of carbon nanotubes infiltrated with lithium and a lithium mixed metal oxide containing nickel, zinc, cobalt, or a mixture thereof.   The battery of claim 1, further comprising a case made from a carbon nanotube composite material.   The battery of claim 7, wherein the composite material comprises polyamide, polyphenylene sulfide, polyether ether ketone, polypropylene, bispolyamide, bismaleimide, epoxy, and combinations thereof.   The battery according to claim 1, wherein the separator is a porous polyethylene film, a polyethylene film, or a combination thereof. The battery of claim 1, wherein the carbon nanotube sheet has a density of about 80 g / m ² .   The battery according to claim 1, wherein the battery is a prismatic battery.   The battery of claim 1, wherein the sheet of carbon nanotubes includes well aligned carbon nanotubes.   The battery according to claim 1, wherein the carbon nanotube sheet further contains lithium as an intercalation compound.   The battery according to claim 9, wherein the separator is immersed in an electrolyte solution. A method for forming an anode for use in a battery, the method comprising:
Forming a large amount of carbon nanotubes;
Introducing a semiconductor particle into the bulk mixture to form a bulk mixture of carbon nanotubes and semiconductor particles; and a substantially planar surface defined by a matrix of carbon nanotubes having semiconductor particles interdispersed therein Depositing a large amount of the mixture on the surface to form a body.   The method according to claim 15, wherein the generating step is performed in the presence of lithium.   16. The method of claim 15, further comprising mixing lithium with a volatile carrier and evaporating the volatile carrier to form a carbon nanotube composite sheet.   The method according to claim 15, wherein in the step of dispersing the semiconductor particles, the particles are silicon or germanium particles. A method of forming an anode for use in a battery, the method comprising:
Providing a substantially planar body defined by a matrix of carbon nanotubes;
Dispersing the semiconductor particles within the matrix semiconductor particles using an ultrasonic pulse train. A method of forming a cathode for use in a battery, the method comprising:
Forming a large amount of carbon nanotubes;
Introducing a lithium mixed metal oxide into the bulk mixture to form a bulk mixture of carbon nanotubes and lithium mixed metal oxide; and a matrix of carbon nanotubes comprising lithium mixed metal oxide interdispersed therein Depositing a large amount of the mixture on the moving surface so as to form a substantially planar body defined by.   21. The method of claim 20, further comprising mixing the lithium mixed metal oxide with a volatile support and evaporating the volatile support to form a carbon nanotube composite sheet.   21. The method of claim 20, wherein in the introducing step, the lithium mixed metal oxide comprises lithium and nickel, cobalt, or a mixture thereof.   23. The method of claim 22, wherein in the introducing step, the lithium mixed metal oxide comprises lithium and nickel, cobalt, or a mixture thereof. A method of forming a cathode for use in a battery, the method comprising:
Providing a substantially planar body defined by a matrix of carbon nanotubes;
Spraying a lithium mixed metal oxide onto the matrix. A method of manufacturing a battery, the method comprising:
Introducing a plurality of semiconductor particles into a first sheet of carbon nanotubes to form a negative electrode;
Infiltrating a lithium mixed metal oxide into the second sheet of carbon nanotubes to form a positive electrode;
Placing a separator between the positive electrode and the negative electrode; and sealing the positive electrode, the negative electrode, and the separator with a carbon nanotube sheet case.   26. The method of claim 25, wherein in the introducing step, semiconductor particles are welded onto the carbon nanotubes.   26. The method according to claim 25, wherein in the introducing step, the semiconductor particles are silicon or germanium particles.   26. The method of claim 25, wherein in the infiltrating step, the lithium mixed metal oxide comprises lithium and nickel, cobalt, or a combination thereof.   26. The method of claim 25, wherein in the sealing step, the case comprises a carbon nanotube composite material.   30. The method of claim 29, wherein, in the sealing step, the composite material includes polyamide, polyphenylene sulfide, polyether ether ketone, polypropylene, bispolyamide, bismaleimide, epoxy, and combinations thereof. Method.   26. The method of claim 25, wherein in the placing step, the separator is a porous polyethylene membrane, a polyethylene membrane, or a combination thereof. An anode for use in a battery, the anode comprising:
An anode comprising: a sheet of at least one carbon nanotube; and a plurality of semiconductor particles interdispersed within the sheet. A cathode for use in a battery, the cathode comprising:
A cathode comprising: a sheet of at least one carbon nanotube; and a mixed metal oxide infiltrated into the sheet.