A negative electrode active material for a secondary battery includes a lithium silicate phase; and a silicon phase dispersed in the lithium silicate phase. The lithium silicate phase contains at least one element M selected from the group consisting of alkali metals (except lithium), Group II elements, rare-earth elements, zirconium (Zr), niobium (Nb), tantalum (Ta), vanadium (V), titanium (Ti), phosphorus (P), bismuth (Bi), zinc (Zn), tin (Sn), lead (Pb), antimony (Sb), cobalt (Co), fluorine (F), tungsten (W), aluminum (Al), and boron (B). An electron diffraction image of the negative electrode active material obtained using a transmission electron microscope has a spot image.

The present disclosure provides methods that use polymerized alkali silicate gels. An example method comprises: introducing a polymerized alkali silicate gel into a subterranean formation containing a fault, wherein the polymerized alkali silicate gel is introduced the subterranean formation such that at least a leading edge of polymerized alkali silicate gel is placed in the fault or within about 10 miles from the fault.

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 refers to a stable sodium and iron silicate solution that has a weight ratio of SiO.sub.2 to Na.sub.2O from 1.5 to 2.5 and a total percentage of solids, expressed by the sum of SiO.sub.2 and Na.sub.2O, from 20% to 55%. Said solution also has a soluble iron content, expressed by Fe, from 0.1% to 7%, and a water content from 38% to 79.9%. The present invention also refers to the process for preparing said stable solution of sodium and iron silicate, which comprises the steps of: (a) providing a siliceous material containing iron; (b) submitting said siliceous material containing iron to a hydrothermal treatment with caustic soda under high temperature and controlled pressure; and (c) filtering said reacted solution to separate the reacted portion of the hydrothermal treatment from the unreacted portion. Additionally, the present invention refers to the uses of said stable sodium and iron silicate solution.

The present invention refers to a stable sodium and iron silicate solution that has a weight ratio of SiO.sub.2 to Na.sub.2O from 1.5 to 2.5 and a total percentage of solids, expressed by the sum of SiO.sub.2 and Na.sub.2O, from 20% to 55%. Said solution also has a soluble iron content, expressed by Fe, from 0.1% to 7%, and a water content from 38% to 79.9%. The present invention also refers to the process for preparing said stable solution of sodium and iron silicate, which comprises the steps of: (a) providing a siliceous material containing iron; (b) submitting said siliceous material containing iron to a hydrothermal treatment with caustic soda under high temperature and controlled pressure; and (c) filtering said reacted solution to separate the reacted portion of the hydrothermal treatment from the unreacted portion. Additionally, the present invention refers to the uses of said stable sodium and iron silicate solution.

The invention relates to a method for producing a silane-modified silicate. In order to obtain optimal corrosion protection properties, a silane compound according to the invention is at least partially hydrolyzed and/or condensed in the presence of a silicate compound at a pH value greater than or equal to 8 and then a pH value less than or equal to 7 is set by adding acid. The invention further relates to an aqueous acidic passivation composition for metal substrate coated with the passivation composition.

A method of producing a synthetic functionalized additive including the steps of mixing an amount of a magnesium salt with a fluid medium to produce a magnesium-containing fluid, adding an amount of a silane to the magnesium-containing fluid to produce a reactant mix, adding an amount of an aqueous hydroxide to the reactant mix to produce a reaction mixture, mixing the reaction mixture for a mix period, refluxing the reaction mixture for a reflux period to produce a product mix, treating the product mix to separate the synthetic functionalized additive.

An anode active material for a lithium secondary battery is provided which includes a composite including: a silicon-based material including a lithium silicate; and a lithium-containing phosphate, wherein a peak intensity ratio B/A is 0.01 to 0.5, wherein A is a peak intensity at 2θ=28.5°, and B is a peak intensity at 2θ=22.3°, when an X-ray diffraction (XRD) analysis is performed using a Cu—Kα ray.

The initial charge/discharge efficiency and cycle characteristics of a non-aqueous electrolyte secondary battery that contains a silicon material as a negative-electrode active material are improved. A negative-electrode active material particle (10) according to an embodiment includes a lithium silicate phase (11) represented by Li.sub.2zSiO.sub.(2+z) {0<z<2} and silicon particles (12) dispersed in the lithium silicate phase (11). A lithium silicate constituting the lithium silicate phase has a crystallite size of 40 nm or less. The crystallite size is calculated using the Scherrer equation from the half-width of a diffraction peak of a (111) plane of the lithium silicate in an XRD pattern obtained by XRD measurement of the negative-electrode active material particle 10.

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.