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Lithium–silicon Battery
Lithium–silicon battery is a name used for a subclass of lithium-ion battery technology that employs a silicon-based anode#Battery or galvanic cell anode, anode and lithium ions as the charge carriers. Silicon based materials generally have a much larger specific capacity, for example 3600 mAh/g for pristine silicon, relative to graphite, which is limited to a maximum theoretical capacity of 372 mAh/g for the fully lithiated state LiC6.Shao, Gaofeng, et al. ''Polymer derived SiOC integrated with graphene aerogel as highly stable Li-ion battery anodes'' ACS Appl. Mater. Interfaces 2020, 12, 41, 46045–46056 Silicon's large volume change (approximately 400% based on crystallographic densities) when lithium is inserted is one of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithium-ion Battery
A lithium-ion or Li-ion battery is a type of rechargeable battery which uses the reversible reduction of lithium ions to store energy. It is the predominant battery type used in portable consumer electronics and electric vehicles. It also sees significant use for grid-scale energy storage and military and aerospace applications. Compared to other rechargeable battery technologies, Li-ion batteries have high energy densities, low self-discharge, and no memory effect (although a small memory effect reported in LFP cells has been traced to poorly made cells). Chemistry, performance, cost and safety characteristics vary across types of lithium-ion batteries. Most commercial Li-ion cells use intercalation compounds as the active materials. The anode or negative electrode is usually graphite, although silicon-carbon is also being increasingly used. Cells can be manufactured to prioritize either energy or power density. Handheld electronics mostly use lithium polymer batteries ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanowire Battery
A nanowire battery uses nanowires to increase the surface area of one or both of its electrodes. Some designs (silicon, germanium and transition metal oxides), 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. Silicon Silicon is an attractive material for applications as lithium battery anodes because it offers advantageous material properties. In particular, silicon has a low discharge potential and a high theoretical charge capacity ten times higher than that of typical graphite anodes currently used in industry. Nanowires could improve these properties by increasing the amount of available surface area in contact with the electrolyte, thereby increasing the anode’s power density and allowing for faster charging and higher current delivery. However, the use of silicon anodes in batteries has been limited by the volume expansion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrofluoric Acid
Hydrofluoric acid is a Solution (chemistry), solution of hydrogen fluoride (HF) in water. Solutions of HF are colourless, acidic and highly Corrosive substance, corrosive. It is used to make most fluorine-containing compounds; examples include the commonly used pharmaceutical antidepressant medication fluoxetine (Prozac) and the material polytetrafluoroethylene, PTFE (Teflon). Elemental fluorine is produced from it. It is commonly used to Etching (microfabrication), etch glass and silicon wafers. Uses Production of organofluorine compounds The principal use of hydrofluoric acid is in organofluorine chemistry. Many organofluorine compounds are prepared using HF as the fluorine source, including Polytetrafluoroethylene, Teflon, fluoropolymers, fluorocarbons, and refrigeration, refrigerants such as freon. Many pharmaceuticals contain fluorine. Production of inorganic fluorides Most high-volume inorganic fluoride compounds are prepared from hydrofluoric acid. Foremost are Na3AlF6 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbonate
A carbonate is a salt of carbonic acid (H2CO3), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word ''carbonate'' may also refer to a carbonate ester, an organic compound containing the carbonate group C(=O)(O–)2. The term is also used as a verb, to describe carbonation: the process of raising the concentrations of carbonate and bicarbonate ions in water to produce carbonated water and other carbonated beverageseither by the addition of carbon dioxide gas under pressure or by dissolving carbonate or bicarbonate salts into the water. In geology and mineralogy, the term "carbonate" can refer both to carbonate minerals and carbonate rock (which is made of chiefly carbonate minerals), and both are dominated by the carbonate ion, . Carbonate minerals are extremely varied and ubiquitous in chemically precipitated sedimentary rock. The most common are calcite or calcium carbonate, CaCO3, the chief constituent of limestone (as well a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithium Hexafluorophosphate
Lithium hexafluorophosphate is an inorganic compound with the formula Li PF6. It is a white crystalline powder. Production LiPF6 is manufactured by reacting phosphorus pentachloride with hydrogen fluoride and lithium fluoride :PCl5 + LiF + 5 HF → LiPF6 + 5 HCl Suppliers include Targray and Morita Chemical Industries Co., Ltd Chemistry The salt is relatively stable thermally, but loses 50% weight at 200 °C (392 °F). It hydrolyzes near 70 °C (158 °F) according to the following equation forming highly toxic HF gas: :LiPF6 + H2O → HF + PF5 + LiOH Owing to the Lewis acidity of the Li+ ions, LiPF6 also catalyses the tetrahydropyranylation of tertiary alcohols. In lithium-ion batteries, LiPF6 reacts with Li2CO3, which may be catalysed by small amounts of HF: :LiPF6 + Li2CO3 → POF3 + CO2 + 3 LiF Application The main use of LiPF6 is in commercial secondary batteries, an application that exploits its high solubility in polar aprotic solvents. Specif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Resistivity And Conductivity
Electrical resistivity (also called specific electrical resistance or volume resistivity) is a fundamental property of a material that measures how strongly it resists electric current. A low resistivity indicates a material that readily allows electric current. Resistivity is commonly represented by the Greek letter (rho). The SI unit of electrical resistivity is the ohm-meter (Ω⋅m). For example, if a solid cube of material has sheet contacts on two opposite faces, and the resistance between these contacts is , then the resistivity of the material is . Electrical conductivity or specific conductance is the reciprocal of electrical resistivity. It represents a material's ability to conduct electric current. It is commonly signified by the Greek letter ( sigma), but (kappa) (especially in electrical engineering) and (gamma) are sometimes used. The SI unit of electrical conductivity is siemens per metre (S/m). Resistivity and conductivity are intensi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Decomposition
Chemical decomposition, or chemical breakdown, is the process or effect of simplifying a single chemical entity (normal molecule, reaction intermediate, etc.) into two or more fragments. Chemical decomposition is usually regarded and defined as the exact opposite of chemical synthesis. In short, the chemical reaction in which two or more products are formed from a single reactant is called a decomposition reaction. The details of a decomposition process are not always well defined but some of the process is understood; much energy is needed to break bonds. Since all decomposition reactions break apart the bonds holding it together in order to produce into its simpler basic parts, the reactions would require some form of this energy in varying degrees. Because of this fundamental rule, it is known that most of these reactions are endothermic although exceptions do exist. The stability of a chemical compound is eventually limited when exposed to extreme environmental conditions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Current Collector
Electric current collectors are used by trolleybuses, trams, electric locomotives or EMUs to carry electrical power from overhead lines, electrical third rails, or ground-level power supplies to the electrical equipment of the vehicles. Those for overhead wires are roof-mounted devices, those for rails are mounted on the bogies. Typically, electric current connectors have one or more spring-loaded arms that press a collector or contact shoe against the rail or overhead wire. As the vehicle moves, the contact shoe slides along the wire or rail to draw the electricity needed to run the vehicle's motor. The current collector arms are electrically conductive but mounted insulated on the vehicle's roof, side or base. An insulated cable connects the collector with the switch, transformer or motor. The steel rails of the tracks act as the electrical return. Electric vehicles that collect their current from an overhead line system use different forms of one- or two-arm pantograph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reduction Potential
Redox potential (also known as oxidation / reduction potential, ''ORP'', ''pe'', ''E_'', or E_) is a measure of the tendency of a chemical species to acquire electrons from or lose electrons to an electrode and thereby be reduced or oxidised respectively. Redox potential is expressed in volts (V). Each species has its own intrinsic redox potential; for example, the more positive the reduction potential (reduction potential is more often used due to general formalism in electrochemistry), the greater the species' affinity for electrons and tendency to be reduced. Measurement and interpretation In aqueous solutions, redox potential is a measure of the tendency of the solution to either gain or lose electrons when it is subjected to change by introduction of a new species. A solution with a higher (more positive) reduction potential than the new species will have a tendency to gain electrons from the new species (i.e. to be reduced by oxidizing the new species) and a solution with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrolyte
An electrolyte is a medium containing ions that is electrically conducting through the movement of those ions, but not conducting electrons. This includes most soluble salts, acids, and bases dissolved in a polar solvent, such as water. Upon dissolving, the substance separates into cations and anions, which disperse uniformly throughout the solvent. Solid-state electrolytes also exist. In medicine and sometimes in chemistry, the term electrolyte refers to the substance that is dissolved. Electrically, such a solution is neutral. If an electric potential is applied to such a solution, the cations of the solution are drawn to the electrode that has an abundance of electrons, while the anions are drawn to the electrode that has a deficit of electrons. The movement of anions and cations in opposite directions within the solution amounts to a current. Some gases, such as hydrogen chloride (HCl), under conditions of high temperature or low pressure can also function as electrolytes. El ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eduard Zintl
Eduard Zintl (21 January 1898 – 17 January 1941) was a German chemist. He gained prominence for research on intermetallic compounds. Family background After his family moved from Weiden and Bayreuth to Munich and after he had finished school he was drafted for military service during World War I. At the age of 21 he started studying at the University of Munich with Otto Hönigschmid. He was an excellent student, and later became an assistant for Otto Hönigschmid, head of the German atomic weight laboratory. Career He earned his PhD in 1923, at the age of 25, with a thesis on the molar mass of bromine. He stayed with Otto Hönigschmid's group, where he was involved in the supervision of PhD students, for example Josef Goubeau and Günther Rienäcker. From 1928 till 1933 he was professor of inorganic chemistry at the University of Freiburg. During this period he studied the structure of complex anions formed by metals in a solution of sodium in ammonia. a(NH3)xsup>+4 b9sup>4&m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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