A cobalt oxide precursor powder for use in preparing a positive electrode active material and methods of production thereof are described. The precursor powder comprises particles has a Fd-3m structure and a formula Co.sub.1-yA.sub.yO.sub.x, wherein 1<x≤4/3, 0≤y≤0.05, wherein A comprises at least one element from the group consisting of Ni, Mn, Al, Mg, Ti, and Zr. The particles have a D50≥15 μm and a compressive strength at least 100 MPa and at most 170 MPa.

The invention relates to a host material for stabilizing a Li metal electrode, fabricating methods and applications of the same. The host material includes crumpled graphene balls operably defining a scaffold having volumes and voids inside and in between the crumpled graphene balls so as to allow uniform and stable Li deposition/dissolution inside and in between the crumpled graphene balls without electrode volume fluctuations or with sufficiently small electrode volume fluctuations. The crumpled paper ball-like structures of graphene particles can readily assemble to yield the scaffold with scalable Li loading up to 10 mAh cm-2 within tolerable volume fluctuations. High Coulombic efficiency of 97.5% over 750 cycles (1500 hours) is achieved. Plating/stripping Li up to 12 mAh cm-2 on the crumpled graphene scaffold does not experience dendrite growth.

Provided are a novel metahalloysite powder and a production method thereof, which are not present in the prior art. The metahalloysite powder is a powder which comprises granules of aggregated metahalloysite comprising metahalloysite nanotubes, which are tube-shaped metahalloysite. The production method comprises a step of preparing a halloysite slurry which comprises halloysite nanotubes, a step for formulating a powder from the slurry, and a step for firing the formulated powder at a firing temperature of 500° C. or above.

The present invention provides a novel material using a meta-halloysite that does not exist prior art, and a production method therefor. The meta-halloysite powder of the present invention is characterized in that: the meta-halloysite is covered by elemental carbon; the meta-halloysite contains elemental carbon; the meta-halloysite powder is a powder containing granules formed by the aggregation of meta-halloysite comprising meta-halloysite nanotubes covered by elemental carbon; or the meta-halloysite powder is powder containing granules formed by the aggregation of meta-halloysite comprising meta-halloysite nanotubes, which are tubular meta-halloysite, wherein the meta-halloysite contains elemental carbon.

Porous silicon and methods for preparation and use of the same are disclosed. The porous silicon materials have utility either alone or in combination with other materials, for example, combined with carbon particles for energy storage applications.

Provided herein are methods and systems to form calcium carbonate comprising vaterite, comprising dissolving lime in an aqueous base solution under one or more precipitation conditions to produce a precipitation material comprising calcium carbonate and a supernatant solution, wherein the calcium carbonate comprises vaterite.

Provided herein are methods and systems to form calcium carbonate comprising vaterite, comprising dissolving limestone in an aqueous base solution under one or more precipitation conditions to produce a precipitation material comprising calcium carbonate and a supernatant solution, wherein the calcium carbonate comprises vaterite.

A granular conductive carbon black and a preparation method thereof, belonging to the technical field of conductive carbon blacks. The method for preparing a granular conductive carbon black includes making a raw material of the conductive carbon black undergo moistening with water of a temperature of 80° C. or higher, performing wet granulation and drying in sequence. The raw material of the conductive carbon black is infiltrated by the water of a temperature of 80° C. or higher, so that the hydrophilic property of the raw material of the conductive carbon black is enhanced, the water of a temperature of 80° C. or higher enters the microporous structures of the raw material of the conductive carbon black, then a good moistening effect is achieved, and further the granular conductive acetylene carbon black with uniform particle size distribution is prepared through wet granulation and drying.

The present invention provides a method for producing a powder containing zirconia particles and a fluorescent agent that enables easy production of a zirconia sintered body having both high translucency and high strength despite containing a fluorescent agent. The present invention relates to a method for producing a zirconia particle- and fluorescent agent-containing powder, comprising: a mixing step of mixing a zirconia particle-containing slurry and a liquid-state fluorescent agent; and a drying step of drying the slurry containing the zirconia particles and the fluorescent agent. Preferably, the fluorescent agent comprises a metallic element, and the powder comprises the fluorescent agent in an amount of 0.001 to 1 mass % in terms of an oxide of the metallic element relative to a mass of zirconia. Preferably, the zirconia particles have an average primary particle diameter of 30 nm or less. Preferably, the zirconia particles comprises 2.0 to 9.0 mol % yttria.

The present invention provides a zirconia sintered body containing a fluorescent agent and having excellent translucency and excellent strength. The present invention also provides a zirconia shaped body and a zirconia calcined body from which the zirconia sintered body can be obtained. The present invention relates to a zirconia sintered body comprising a fluorescent agent, wherein the zirconia sintered body comprises 4.5 to 9.0 mol % yttria, and has a crystal grain size of 180 nm or less, and a three-point flexural strength of 500 MPa or more. The present invention relates to a zirconia shaped body comprising a fluorescent agent, wherein the zirconia shaped body comprises 4.5 to 9.0 mol % yttria, and has a three-point flexural strength of 500 MPa or more after being sintered at 1,100° C. for 2 hours under ordinary pressure, and a crystal grain size of 180 nm or less after being sintered at 1,100° C. for 2 hours under ordinary pressure. The present invention relates to a zirconia calcined body comprising a fluorescent agent, wherein the zirconia calcined body comprises 4.5 to 9.0 mol % yttria, and has a three-point flexural strength of 500 MPa or more after being sintered at 1,100° C. for 2 hours under ordinary pressure, and a crystal grain size of 180 nm or less after being sintered at 1,100° C. for 2 hours under ordinary pressure.