A method includes forming a reaction bed containing feed agglomerates in a reaction chamber by heating the feed agglomerates. Individual feed agglomerates initially contain particles of a gypsum source and of a silicon source approximately homogeneously distributed throughout the individual agglomerates. The gypsum and silicon in the feed agglomerates react during the heating in the reaction chamber and, thereby, form processed agglomerates that contain silicates of calcium and an increased amount of amorphous silicon compared to the feed agglomerates before the heating. The method includes generating off gas from the reaction bed, the off gas containing oxides of sulfur, and removing the processed agglomerates from the reaction chamber.

Disclosed is a negative electrode active material which includes: a silicon oxide composite including i) Si, ii) a silicon oxide represented by SiO.sub.x (0 < x ≤ 2), and iii) magnesium silicate containing Si and Mg; and a carbon coating layer positioned on the surface of the silicon oxide composite and including a carbonaceous material, wherein X-ray diffractometry of the negative electrode active material shows peaks of Mg.sub.2SiO.sub.4 and MgSiO.sub.3 at the same time and shows no peak of MgO; the ratio of peak intensity, I (Mg.sub.2SiO.sub.4)/I (MgSiO.sub.3), which is intensity I (Mg.sub.2SiO.sub.4) of peaks that belong to Mg.sub.2SiO.sub.4 to intensity I (MgSiO.sub.3) of peaks that belong to MgSiO.sub.3 is smaller than 1, the peaks that belong to Mg.sub.2SiO.sub.4 are observed at 2θ = 32.2 ± 0.2°, and the peaks that belong to MgSiO.sub.3 are observed at 2θ = 30.9 ± 0.2°.

The present invention relates to solvothermal vapor synthesis methods for the crystallization of a phase from a mixture of selected inorganic or organic precursors in an unsaturated vapor-phase reaction medium.

The present invention relates to solvothermal vapor synthesis methods for the crystallization of a phase from a mixture of selected inorganic or organic precursors in an unsaturated vapor-phase reaction medium.

The present invention relates to inorganic fibres having a composition comprising: 61.0 to 70.8 wt % SiO.sub.2; 28.0 to 39.0 wt % CaO; 0.10 to 0.85 wt % MgO other components, if any, providing the balance up to 100 wt %,

The sum of SiO.sub.2 and CaO is greater than or equal to 98.8 wt % and the other components comprise less than 0.70 wt % Al.sub.2O.sub.3, if any.

The present invention relates to inorganic fibres having a composition comprising: 61.0 to 70.8 wt % SiO.sub.2; 28.0 to 39.0 wt % CaO; 0.10 to 0.85 wt % MgO other components, if any, providing the balance up to 100 wt %,

The sum of SiO.sub.2 and CaO is greater than or equal to 98.8 wt % and the other components comprise less than 0.70 wt % Al.sub.2O.sub.3, if any.

One aspect of the present invention is a positive active material that contains an oxide containing lithium, a transition metal element and a typical element, and having an antifluorite crystal structure, in which the transition metal element is cobalt, iron, copper, manganese, nickel, chromium, or a combination thereof, the typical element is a group 13 element, a group 14 element, phosphorus, antimony, bismuth, tellurium or a combination thereof, and a molar ratio of a content of the typical element to a total content of the transition metal element and the typical element in the oxide is more than 0.05 and 0.5 or less.

One aspect of the present invention is a positive active material that contains an oxide containing lithium, a transition metal element and a typical element, and having an antifluorite crystal structure, in which the transition metal element is cobalt, iron, copper, manganese, nickel, chromium, or a combination thereof, the typical element is a group 13 element, a group 14 element, phosphorus, antimony, bismuth, tellurium or a combination thereof, and a molar ratio of a content of the typical element to a total content of the transition metal element and the typical element in the oxide is more than 0.05 and 0.5 or less.

A negative electrode active material including a core containing SiO.sub.x (0≤x<2) and a lithium-containing compound, and a shell disposed on the core and containing SiO.sub.x (0≤x<2) and magnesium silicate.

The present invention relates to an energy storage device comprising a silicate comprises a formula:
M.sub.vM1.sub.wM2.sub.xSi.sub.yO.sub.z
where M is selected from the group consisting of Li, Na, K, Al, and Mg M1 is selected from the group consisting of alkaline metals, alkaline earth metals, Ti, Mn, Fe, La, Zr, Ce, Ta, Nb, V and combinations thereof; M2 is selected from the group consisting of B, Al, Ga, Ge or combinations thereof; v, y and z are greater than 0; w and/or x is greater than 0; y≥x; and wherein M.sub.vM1.sub.wM2.sub.xSi.sub.yO.sub.z accounts for at least 90 wt % of the composition.