Siegenite | |
---|---|
General | |
Category | Sulfide mineral Thiospinel group Spinel structural group |
Formula (repeating unit) | (Ni,Co)3S4 |
IMA symbol | Seg [1] |
Strunz classification | 2.DA.05 |
Crystal system | Cubic |
Crystal class | m3m |
Space group | Fd3m (#227) |
Unit cell | a = 9.33 Å; V = 810.94Å3 |
Identification | |
Formula mass | 304.3 - 305 g/mol |
Color | Light to steel-grey, violet-gray (tarnished) |
Crystal habit | As octahedral crystals, granular, massive |
Twinning | On {111}; polysynthetic |
Cleavage | Imperfect on {001} |
Fracture | Irregular to uneven, sub-conchoidal |
Mohs scale hardness | 4.5 - 5.5 |
Luster | Metallic |
Streak | Grayish black |
Diaphaneity | Opaque |
Density | 4.5 - 4.8 g/cm3 (Measured) 4.83 g/cm3 (Calculated) |
References | [2] [3] [4] |
Siegenite (also called grimmite, or nickel cobalt sulfide) is a ternary transition metal dichalcogenide compound with the chemical formula (Ni,Co)3S4. It has been actively studied as a promising material system for electrodes in electrochemical energy applications due to its better conductivity, greater mechanical and thermal stability, and higher performance compared to metal oxides currently in use. [5] Potential applications of this material system include supercapacitors, batteries, electrocatalysis, dye-sensitized solar cells, photocatalysis, glucose sensors, and microwave absorption. [6]
In synthetic chemistry, a range of chemical compositions with the formula NixCo3-xS4 (0 < x < 3) are often referred to as the siegenite system. However, according to the new IMA list of minerals (updated November 2022), the normal spinel NiCo2S4 is called grimmite, the inverse spinel CoNi2S4 is called siegenite, and the endmembers Ni2+(Ni3+)2S4 and Co2+(Co3+)2S4 are called polydymite and linnaeite, respectively. [7] In 2020, NiCo2S4 (grimmite) is approved as a valid mineral species by the IMA. [8]
Siegenite was first described in 1850 for an occurrence in the Stahlberg Mine in Müsen, Siegerland, North Rhine-Westphalia, Germany and named for the locality. [2] It occurs in hydrothermal copper-nickel-iron sulfide bearing veins associated with chalcopyrite, pyrrhotite, galena, sphalerite, pyrite, millerite, gersdorffite and ullmannite. [3]
It occurs in a variety of deposits worldwide, including Brestovsko in the central Bosnian Mountains of Serbia; at Kladno in the Czech Republic; Blackcraig, Kirkcudbrightshire, Scotland. In the United States occurrences include the Mine la Motte of Madison County and the Buick mine, Bixby, Iron County and in the Sweetwater mine of Reynolds County in the Lead Belt of Missouri. In Canada, it is known from the Langis mine, Cobalt-Gowganda area, Ontario. In Africa it occurs at Shinkolobwe, Katanga Province and Kilembe, Uganda. In Japan, it is reported from the Kamaishi mine, Iwate Prefecture, and the Yokozuru mine, north Kyushu. It also occurs at Kalgoorlie, Western Australia. [3] It is found at the Browns deposit, Batchelor, Northern Territory, Australia. [2]
Siegenite is a member of the thiospinel group, which belongs to the cubic space group (#227) and has the Pearson symbol . Similar to normal spinels, a normal thiospinel unit cell consists of eight FCC sub unit cells of two different types, where S2- anions occupy all the FCC lattice points. The first type of sub unit cell has 2+ cations occupying 2 of the 8 tetrahedral sites and 3+ cations occupying 3/2 of the 4 octahedral sites. The second type of sub unit cell has only 3+ cations occupying 5/2 of the 4 octahedral sites. These two types of sub unit cells are alternatively stacked, forming a NaCl-type superstructure.
For a normal thiospinel (NiCo2S4), Ni2+ cations occupy 1/8 of the tetrahedral sites to form NiS4 tetrahedra and Co3+ cations occupy 1/2 of the octahedral sites to form CoS6 octahedra. Each tetrahedron shares corners with 12 neighboring octahedra, and each octahedron shares corners with 6 tetrahedra and edges with 6 octahedra. For an inverse thiospinel (CoNi2S4), Ni2+ occupy 1/8 of the octahedral sites and Co3+ occupy 1/4 of the tetrahedra sites and 1/4 of the octahedral sites. For a mixed/complex thiospinel, both metal ions occupy tetrahedral and octahedral sites and can be expressed as (AxB1-x)Td[A2-xBx]OhX4 (0 < x < 1), where A and B are metal ions, x is the degree of inversion, and and denote the tetrahedral and octahedral sites, respectively.
The powder X-ray diffraction (XRD) pattern of siegenite exhibits strong diffraction signals between 20° and 60° 2θ angles. The lattice constant of siegenite is measured to be 9.319 Å based on the strongest reflection at around 32°, corresponding to lattice plane (311), which agrees with the calculated lattice constant of 9.325 Å. [9] [10]
Unlike many binary and ternary semiconductor oxides, NiCo2S4 exhibits metallic properties and high electrical conductivity, which makes it useful as an electrode material in energy storage devices. The resistivity of NiCo2S4 is ~103 μΩ cm at room temperature and its temperature coefficient of resistivity is positive and stays constant between 40 K and 300 K, which is indicative of a metallic compound. [9] NiCo2S4 also has a very low Seebeck coefficient of 5 μV K–1 and a carrier density of 3.18 × 1022 cm−3 higher than that of silver. [9]
Reported synthetic routes of nickel cobalt sulfide include hydrothermal [11] [12] and solvothermal [13] reactions, solvent-free thermal decomposition of xanthates, [14] SILAR method for thin films, [15] and solution-phase organometallic synthesis. [16] The hydrothermal reaction is the most widely used synthesis method to fabricate intricate nanostructures on highly porous substrates, yielding hierarchical structures that maximize redox-active surface areas and promote high-rate supercapacitive performance of Ni-Co-S-based electrodes.
(Ni,Co)3S4 is a promising electrode material for batteries and supercapacitors. Since the electronegativity of sulfur is lower than that of oxygen, (Ni,Co)3S4 has a more flexible lattice compared to its oxide counterpart, which allows easier electron and ion transport through the structure. [17] Its high ionic conductivity can be attributed to the abundance of available cation sites in the thiospinel structure, and its high redox activity comes from the highly electrochemically active Ni2+/Ni3+ and Co2+/Co3+ redox couples. In literatures, nanoporous Ni-Co-S composite materials have been shown to have both high specific capacity in Li-based batteries and high capacitance in supercapacitors. [6]
(Ni,Co)3S4 has been considered as an alternative electrocatalyst for HER and OER reactions because of its high conductivity and low cost. It is reported that a overpotential of 87 mV for HER and 251 mV for HER can be achieved using NiCo2S4-based electrode, showing good potential for water splitting applications. [6]
An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit. Electrodes are essential parts of batteries that can consist of a variety of materials depending on the type of battery.
Pentlandite is an iron–nickel sulfide with the chemical formula (Fe,Ni)9S8. Pentlandite has a narrow variation range in nickel to iron ratios (Ni:Fe), but it is usually described as 1:1. In some cases, this ratio is skewed by the presence of pyrrhotite inclusions. It also contains minor cobalt, usually at low levels as a fraction of weight.
A lithium-ion or Li-ion battery is a type of rechargeable battery which uses the reversible reduction of lithium ions to store energy. The negative electrode of a conventional lithium-ion cell is typically graphite, a form of carbon. This negative electrode is sometimes called the anode as it acts as an anode during discharge. The positive electrode is typically a metal oxide; the positive electrode is sometimes called the cathode as it acts as a cathode during discharge. Positive and negative electrodes remain positive and negative in normal use whether charging or discharging and are therefore clearer terms to use than anode and cathode which are reversed during charging.
Ullmannite is a nickel antimony sulfide mineral with formula: NiSbS. Considerable substitution occurs with cobalt and iron in the nickel site along with bismuth and arsenic in the antimony site. A solid solution series exists with the high cobalt willyamite.
Greigite is an iron sulfide mineral with the chemical formula Fe2+Fe3+2S4. It is the sulfur equivalent of the iron oxide magnetite (Fe3O4). It was first described in 1964 for an occurrence in San Bernardino County, California, and named after the mineralogist and physical chemist Joseph W. Greig (1895–1977).
Carrollite, CuCo2S4, is a sulfide of copper and cobalt, often with substantial substitution of nickel for the metal ions, and a member of the linnaeite group. It is named after the type locality in Carroll County, Maryland, US, at the Patapsco mine, Sykesville.
Lithium iron phosphate or lithium ferro-phosphate (LFP) is an inorganic compound with the formula LiFePO
4. It is a gray, red-grey, brown or black solid that is insoluble in water. The material has attracted attention as a component of lithium iron phosphate batteries, a type of Li-ion battery. This battery chemistry is targeted for use in power tools, electric vehicles, solar energy installations and more recently large grid-scale energy storage.
Lithium cobalt oxide, sometimes called lithium cobaltate or lithium cobaltite, is a chemical compound with formula LiCoO
2. The cobalt atoms are formally in the +3 oxidation state, hence the IUPAC name lithium cobalt(III) oxide.
In crystallography, the hexagonal crystal family is one of the six crystal families, which includes two crystal systems and two lattice systems. While commonly confused, the trigonal crystal system and the rhombohedral lattice system are not equivalent. In particular, there are crystals that have trigonal symmetry but belong to the hexagonal lattice.
Pimelite was discredited as a mineral species by the International Mineralogical Association (IMA) in 2006, in an article which suggests that “pimelite” specimens are probably willemseite, or kerolite. This was a mass discreditation, and not based on any re-examination of the type material. Nevertheless, a considerable number of papers have been written, verifying that pimelite is a nickel-dominant smectite. It is always possible to redefine a mineral wrongly discredited.
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. It 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.
The spinels are any of a class of minerals of general formulation AB
2X
4 which crystallise in the cubic (isometric) crystal system, with the X anions arranged in a cubic close-packed lattice and the cations A and B occupying some or all of the octahedral and tetrahedral sites in the lattice. Although the charges of A and B in the prototypical spinel structure are +2 and +3, respectively, other combinations incorporating divalent, trivalent, or tetravalent cations, including magnesium, zinc, iron, manganese, aluminium, chromium, titanium, and silicon, are also possible. The anion is normally oxygen; when other chalcogenides constitute the anion sublattice the structure is referred to as a thiospinel.
A lithium ion manganese oxide battery (LMO) is a lithium-ion cell that uses manganese dioxide, MnO
2, as the cathode material. They function through the same intercalation/de-intercalation mechanism as other commercialized secondary battery technologies, such as LiCoO
2. Cathodes based on manganese-oxide components are earth-abundant, inexpensive, non-toxic, and provide better thermal stability.
Pseudocapacitance is the electrochemical storage of electricity in an electrochemical capacitor known as a 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.
NASICON is an acronym for sodium (Na) Super Ionic CONductor, which usually refers to a family of solids with the chemical formula Na1+xZr2SixP3−xO12, 0 < x < 3. In a broader sense, it is also used for similar compounds where Na, Zr and/or Si are replaced by isovalent elements. NASICON compounds have high ionic conductivities, on the order of 10−3 S/cm, which rival those of liquid electrolytes. They are caused by hopping of Na ions among interstitial sites of the NASICON crystal lattice.
Nickel manganese oxides, or nickel manganates, are spinel structure compounds of Nickel, Manganese and Oxygen of the form: Ni(x)Mn(3-x)O(y)
Lithium nickel manganese cobalt oxides (abbreviated NMC, Li-NMC, LNMC, or NCM) are mixed metal oxides of lithium, nickel, manganese and cobalt with the general formula LiNixMnyCo1-x-yO2. These materials are commonly used in lithium-ion batteries for mobile devices and electric vehicles, acting as the positively charged cathode.
Conductive metal−organic frameworks are a class of metal–organic frameworks with intrinsic ability of electronic conduction. Metal ions and organic linker self-assemble to form a framework which can be 1D/2D/3D in connectivity. The first conductive MOF, Cu[Cu(2,3-pyrazinedithiol)2] was described in 2009 and exhibited electrical conductivity of 6 × 10−4 S cm−1 at 300 K.
This is a history of the lithium-ion battery.