New formulation for pyrite scale removal from oil and gas wells and a method of pyrite scale removal are disclosed. The chemical formulation is composed of K.sub.2B.sub.4O.sub.7-4H.sub.2O, in a concentration of about 9-20 wt. % of the composition, preferably about 14 wt. % of the composition. The new formulation has the ability to dissolve pyrite without generation of the toxic H.sub.2S. Furthermore, the new formulation is cheaper and has very low corrosion rate compare to 15 wt. % HCl with corrosion inhibitor. The disclose method uses the disclosed new formulation to dissolve iron sulphide scale, performed at about 100-150° C. and about 500-2000 psi.

A positive electrode active material for a lithium secondary battery and a method for manufacturing the same are disclosed herein. In some embodiments, a positive electrode active material comprises a positive electrode active material powder and a coating layer on a surface of the positive electrode active material powder, where the coating layer comprising a lithium molybdenum compound. The positive electrode active material may improve output and stability in a lithium secondary battery.

The present exemplary embodiments relate to a cathode active material, a manufacturing method thereof, and a lithium secondary battery including the same. A cathode active material according to an exemplary embodiment is a lithium metal oxide particle in the form of a secondary particle including a primary particle, a coating layer including a boron compound is positioned on at least a portion of a surface of the primary particle, and the boron compound includes an amorphous structure.

A material can have a layered structure with at least a first layer, including a carbon-based material or a substrate of a material other than a carbon-based material, a second layer, including a carbon-based material, and a third, intermediate layer that separates and interconnects the first and second layers. The carbon-based material includes at least 50 at. % carbon, has a hexagonal lattice and the layer or layers including the carbon-based material has/have a thickness of 1-20 times the size of a carbon atom. The intermediate layer is a layer that includes a salt having ions that include at least two separate cyclic, planar groups that are capable of forming π-π-stacking with the material of the second layer and that the third, intermediate layer is connected to at least the second layer by π-π-stacking caused by said cyclic planar groups of the salt ions.

An effectively solvent-free alkali metal or alkali earth metal closo-borate salt is prepared in the presence of a non-aqueous solvent where the solvent can be removed to levels below one mole percent of the salt. The process involves the exchange of cations with a closo-borate anion via an acid-base process or a metathesis process. The solvent is removed from the alkali metal or alkali earth metal closo-borate salt by heating. The temperature can be greater than the melting point of the salt but lower than temperatures where decomposition occurs.

A main object of the present disclosure is to provide a cathode active material capable of suppressing the reaction with a solid electrolyte. The present disclosure achieves the object by providing a coated cathode active material comprising: a cathode active material, and a coating portion coating at least a part of a surface of the cathode active material, and the coating portion includes a scandium lithium phosphate based compound or a lithium borate based compound.

A positive electrode active material including a nickel-containing lithium transition metal oxide containing nickel in an amount of 60 mol % or more based on a total number of moles of transition metals excluding lithium, and a coating layer which is formed on a surface of the nickel-containing lithium transition metal oxide and includes a lithium-containing inorganic compound, a nickel oxide, and a nickel oxyhydroxide is provided. A method of preparing the positive electrode active material, and a positive electrode for a lithium secondary battery and a lithium secondary battery which include the positive electrode active material are also provided.

An effectively solvent-free alkali metal or alkali earth metal closo-borate salt is prepared in the presence of a non-aqueous solvent where the solvent can be removed to levels below one mole percent of the salt. The process involves the exchange of cations with a closo-borate anion via an acid-base process or a metathesis process. The solvent is removed from the alkali metal or alkali earth metal closo-borate salt by heating. The temperature can be greater than the melting point of the salt but lower than temperatures where decomposition occurs.

A mineralizer composition for Pidgeon silicothermic process for smelting magnesium consists of fluorite and a boron-containing compound. Amounts of the fluorite and the boron-containing compound meet the following equation:

M.sub.fluo-original=(1−x)M.sub.fluo+(m)(x)M.sub.B,

where, M.sub.fluo-original is a mass of the fluorite required in a conventional Pidgeon silicothermic process in which no boron-containing compound is introduced to replace a fraction or all of the total fluorite, M.sub.fluo is a mass of the fluorite in the composition, M.sub.B is a mass of the boron-containing compound in the composition, 0.5≤x≤1, and 2≤m≤8. A Pidgeon silicothermic process for smelting magnesium is also provided, which employs the mineralizer composition. The composition and process of the disclosure enable reduction and even avoidance of dust pollution caused by fluorite-containing magnesium slag.

A non-linear optical crystal, such as a Lithium triborate (LiB.sub.3O.sub.5 or LBO) crystal, includes a first nanostructured optical surface including distributed pillars and gaps having random heights and cross sections to provide anti-reflection control and scatter control of first light incident on the first structured optical surface. The LBO crystal has an anti-reflective random structured optical surface formed by selective substitution of the surface species Boron-pentoxide (B.sub.3O.sub.5.sup.−) by Lithium Fluoride (LiF), resulting in a depletion layer with low reflectivity and low reflective scatter in the visible, ultraviolet (UV), and near infrared (IR) bands. The LBO crystal with the anti-reflective structured optical surface may be a monolithic structure and thus need not include a coating of an anti-reflective (AR) material, although the LBO crystal may include an optical surface coated by an AR material. The pillars and gaps may be randomly distributed or periodically distributed on the optical surface.