A nanoflower, in chemistry, refers to a compound of certain elements that results in formations which in microscopic view resemble flowers or, in some cases, trees that are called nanobouquets or nanotrees. [1] These formations are nanometers long and thick so they can only be observed using electron microscopy. [2]
Several ways to produce nanoflowers are known:
In supercapacitors, energy is stored because the electrodes are coated with a porous material that soaks up ions like a sponge, usually activated carbon. Nanomeadow supercapacitors store ions in manganese oxide (MnO), a material with a much greater capacity for ions than activated carbon. [4]
Scientists at Research Institute of Chemical Defence (Beijing, China) and Peking University created a nanomeadow of microscopic structures, fuzzy flowers of MnO each about 100 nanometres across on a field of messy carbon nanotube grass grown on a tantalum metal foil. Nanomeadows perform 10 times better than MnO alone and can store twice as much charge as the carbon-based electrodes in existing ultracapacitors. [4]
Carbon is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon makes up only about 0.025 percent of Earth's crust. Three isotopes occur naturally, 12C and 13C being stable, while 14C is a radionuclide, decaying with a half-life of about 5,730 years. Carbon is one of the few elements known since antiquity.
Graphite, archaically referred to as plumbago, is a crystalline form of the element carbon with its atoms arranged in a hexagonal structure. It occurs naturally in this form and is the most stable form of carbon under standard conditions. Under high pressures and temperatures it converts to diamond. Graphite is used in pencils and lubricants. It is a good conductor of heat and electricity. Its high conductivity makes it useful in electronic products such as electrodes, batteries, and solar panels.
Carbon is capable of forming many allotropes due to its valency. Well-known forms of carbon include diamond and graphite. In recent decades, many more allotropes have been discovered and researched including ball shapes such as buckminsterfullerene and sheets such as graphene. Larger scale structures of carbon include nanotubes, nanobuds and nanoribbons. Other unusual forms of carbon exist at very high temperatures or extreme pressures. Around 500 hypothetical 3‑periodic allotropes of carbon are known at the present time, according to the Samara Carbon Allotrope Database (SACADA).
An alkaline battery is a type of primary battery which derives its energy from the reaction between zinc metal and manganese dioxide.
Carbon nanofibers (CNFs), vapor grown carbon fibers (VGCFs), or vapor grown carbon nanofibers (VGCNFs) are cylindrical nanostructures with graphene layers arranged as stacked cones, cups or plates. Carbon nanofibers with graphene layers wrapped into perfect cylinders are called carbon nanotubes.
Buckypaper is a thin sheet made from an aggregate of carbon nanotubes or carbon nanotube grid paper. The nanotubes are approximately 50,000 times thinner than a human hair. Originally, it was fabricated as a way to handle carbon nanotubes, but it is also being studied and developed into applications by several research groups, showing promise as vehicle armor, personal armor, and next-generation electronics and displays.
Alloy steel is steel that is alloyed with a variety of elements in total amounts between 1.0% and 50% by weight to improve its mechanical properties. Alloy steels are broken down into two groups: low alloy steels and high alloy steels. The difference between the two is disputed. Smith and Hashemi define the difference at 4.0%, while Degarmo, et al., define it at 8.0%. Most commonly, the phrase "alloy steel" refers to low-alloy steels.
Carbon nanotubes (CNTs) are cylinders of one or more layers of graphene (lattice). Diameters of single-walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs) are typically 0.8 to 2 nm and 5 to 20 nm, respectively, although MWNT diameters can exceed 100 nm. CNT lengths range from less than 100 nm to 0.5 m.
Nanobatteries are fabricated batteries employing technology at the nanoscale, particles that measure less than 100 nanometers or 10−7 meters. These batteries may be nano in size or may use nanotechnology in a macro scale battery. Nanoscale batteries can be combined together to function as a macrobattery such as within a nanopore battery.
A paper battery is engineered to use a spacer formed largely of cellulose. It incorporates nanoscopic scale structures to act as high surface-area electrodes to improve conductivity.
A nanowire battery uses nanowires to increase the surface area of one or both of its electrodes. Some designs, variations of the lithium-ion battery have been announced, although none are commercially available. All of the concepts replace the traditional graphite anode and could improve battery performance.
Carbide-derived carbon (CDC), also known as tunable nanoporous carbon, is the common term for carbon materials derived from carbide precursors, such as binary (e.g. SiC, TiC), or ternary carbides, also known as MAX phases (e.g., Ti2AlC, Ti3SiC2). CDCs have also been derived from polymer-derived ceramics such as Si-O-C or Ti-C, and carbonitrides, such as Si-N-C. CDCs can occur in various structures, ranging from amorphous to crystalline carbon, from sp2- to sp3-bonded, and from highly porous to fully dense. Among others, the following carbon structures have been derived from carbide precursors: micro- and mesoporous carbon, amorphous carbon, carbon nanotubes, onion-like carbon, nanocrystalline diamond, graphene, and graphite. Among carbon materials, microporous CDCs exhibit some of the highest reported specific surface areas (up to more than 3000 m2/g). By varying the type of the precursor and the CDC synthesis conditions, microporous and mesoporous structures with controllable average pore size and pore size distributions can be produced. Depending on the precursor and the synthesis conditions, the average pore size control can be applied at sub-Angstrom accuracy. This ability to precisely tune the size and shapes of pores makes CDCs attractive for selective sorption and storage of liquids and gases (e.g., hydrogen, methane, CO2) and the high electric conductivity and electrochemical stability allows these structures to be effectively implemented in electrical energy storage and capacitive water desalinization.
Pseudocapacitors store electrical energy faradaically by electron charge transfer between electrode and electrolyte. This is accomplished through electrosorption, reduction-oxidation reactions, and intercalation processes, termed pseudocapacitance.
Rodney S. "Rod" Ruoff is an American physical chemist and nanoscience researcher. He is one of the world experts on carbon materials including carbon nanostructures such as fullerenes, nanotubes, graphene, diamond, and has had pioneering discoveries on such materials and others. Ruoff received his B.S. in Chemistry from the University of Texas at Austin (1981) and his Ph.D. in Chemical Physics at the University of Illinois-Urbana (1988). After a Fulbright Fellowship at the MPI fuer Stroemungsforschung in Goettingen, Germany (1989) and postdoctoral work at the IBM T. J. Watson Research Center (1990–91), Ruoff became a staff scientist in the Molecular Physics Laboratory at SRI International (1991-1996). He is currently UNIST Distinguished Professor at the Ulsan National Institute of Science and Technology (UNIST), and the director of the Center for Multidimensional Carbon Materials, an Institute for Basic Science Center located at UNIST.
A supercapacitor (SC), also called an ultracapacitor, is a high-capacity capacitor with a capacitance value much higher than other capacitors, but with lower voltage limits, that bridges the gap between electrolytic capacitors and rechargeable batteries. It typically stores 10 to 100 times more energy per unit volume or mass than electrolytic capacitors, can accept and deliver charge much faster than batteries, and tolerates many more charge and discharge cycles than rechargeable batteries.
Pseudocapacitance is the electrochemical storage of electricity in an electrochemical capacitor (Pseudocapacitor). This faradaic charge transfer originates by a very fast sequence of reversible faradaic redox, electrosorption or intercalation processes on the surface of suitable electrodes. Pseudocapacitance is accompanied by an electron charge-transfer between electrolyte and electrode coming from a de-solvated and adsorbed ion. One electron per charge unit is involved. The adsorbed ion has no chemical reaction with the atoms of the electrode since only a charge-transfer takes place.
Research in lithium-ion batteries has produced many proposed refinements of lithium-ion batteries. Areas of research interest have focused on improving energy density, safety, rate capability, cycle durability, flexibility, and cost.
Yury Georgievich Gogotsi is a Ukrainian scientist in the field of material chemistry, professor at Drexel University, Philadelphia, PA since the year 2000 in the fields of Materials Science and Engineering and Nanotechnology. Distinguished University and Trustee Chair professor of materials science at Drexel University — director of the A.J. Drexel Nanotechnology Institute.
Vertically aligned carbon nanotube arrays (VANTAs) are a unique microstructure consisting of carbon nanotubes oriented with their longitudinal axis perpendicular to a substrate surface. These VANTAs effectively preserve and often accentuate the unique anisotropic properties of individual carbon nanotubes and possess a morphology that may be precisely controlled. VANTAs are consequently widely useful in a range of current and potential device applications.
A conductive agent is used to ensure the electrode has good charge and discharge performance. Usually, a certain amount of conductive material is added during the production of the pole piece, and the micro current is collected between the active material and the current collector to reduce the micro current. The contact resistance of the electrode accelerates the rate of movement of electrons, and at the same time, can effectively increase the migration rate of lithium ions in the electrode material, thereby improving the charge and discharge efficiency of the electrode. The conductive agent carbon black is used for improving the conductivity of the electrodes and decreasing the resistance of interaction.
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