A preparation method for a spherical silica powder filler, comprises the following steps: S1, providing spherical polysiloxane comprising T units by means of a hydrolysis condensation reaction of R.sub.1SiX.sub.3, wherein R.sub.1 is hydrogen atom or an independently selectable organic group having 1 to 18 carbon atoms, X is a hydrolyzable group, and the T unit is R.sub.1SiO.sub.3—; and S2, calcining the spherical polysiloxane under the condition of a dry oxidizing gas atmosphere at a calcining temperature between 850° C. and 1200° C., so as to obtain a spherical silica powder filler having a low hydroxyl content. The spherical silica powder filler is composed of at least one selected from Q.sub.1 unit, Q.sub.2 unit, Q.sub.3 unit and Q.sub.4 unit, wherein Q.sub.1 unit is Si(OH).sub.3O—, Q.sub.2 unit is Si(OH).sub.2O.sub.2—,Q.sub.3 unit is SiOHO.sub.3—, Q.sub.4 unit is SiO.sub.4—, and the content of Q.sub.4 unit is greater than or equal to 95%.

The present invention provides for a process for synthesis of carbon beads comprising sub-micron size, micron size or milli size. The process enables modulation of the viscous slurry for synthesis of the carbon beads with improved physico-chemical properties. The process enhances ability of the carbon beads to withstand extreme pH and high temperatures. The present invention also provides a composition for synthesis of the carbon beads. The present invention also provides a microfluidic droplet generator for synthesizing the carbon beads. The carbon beads synthesized by the present invention are applicable in separation, filtration, purification, wires and cables, electrodes, sensor, composite and additive manufacturing, pharmaceutical delivery applications.

Described herein are low or no-cobalt materials useful as electrode active materials in a cathode for lithium or lithium-ion batteries. For example, compositions of matter are described herein, such as electrode active materials that can be incorporated into an electrode, such as a cathode. The disclosed electrode active materials exhibit high specific energy and voltage, and can also exhibit high rate capability and/or long operational lifetime.

The present disclosure relates to mesoporous silica wrapped nanoparticle composite nanomaterial, preparation method thereof, and use thereof. In the present disclosure, a nanoparticle is dispersed in an aqueous ethanol solution. Then, ammonia water is added to adjust the pH. After that, cetyltrimethylammonium bromide in an aqueous ethanol solution is added dropwise, and ultrasound is continued, before tetraethyl orthosilicate is added dropwise. The mixture is purified to produce a composite nanomaterial that is stable, controllable, and consistent in size; the shell of the composite nanomaterial is mesoporous silica, the core of the composite nanomaterial is a nanoparticle. Dual-core or triple-core nanoparticles of different kinds/functions can be wrapped into a single mesoporous silica shell to achieve multi-core wrapping. The method is universal and may be used to wrap various nanometers. The preparation procedure is environmentally friendly, efficient, and may be carried out at room temperature.

The present invention relates to a bismuth tungstate/bismuth sulfide/molybdenum disulfide heterojunction ternary composite material and a preparation method and application thereof. The composite material is composed of bismuth tungstate, bismuth sulfide and molybdenum disulfide in an ordered layered way, Bi.sub.2WO.sub.6 is an orthorhombic system, Bi.sub.2S.sub.3 is a p-type semiconductor located on a (130) crystal face, MoS.sub.2 is a layered transition metal sulfide located on a (002) crystal face, the whole composite material is of a spherical structure with an unsmooth surface, and a layer of nanosheets uniformly grow on an outer layer. The average particle size of composite materials is in the range of 2.4-2.6 μm. The spherical Bi.sub.2WO.sub.6/Bi.sub.2S.sub.3/MoS.sub.2 heterojunction ternary composite material prepared in the present invention has good adsorption of Cr(VI) and high catalytic reduction ability under visible light.

The present invention relates to a positive electrode active material with improved electrochemical properties and stability and a lithium secondary battery using a positive electrode comprising the same, wherein secondary particles formed by aggregation of a plurality of primary particles are provided as aggregates of primary particles in which a concentration gradient of the doping metal is formed from a grain boundary between the primary particles toward a center portion of the primary particle.

A device for synthesising core-shell nanoparticles by laser pyrolysis is provided. The device includes a reactor having a first chamber for the synthesis of the core, provided with an inlet for a core precursor, a second chamber for the synthesis of the shell, provided with an inlet for a shell precursor, and at least one communication channel between the two chambers to transmit the cores of the nanoparticles intended to be formed from the first chamber towards the second chamber. The device also includes an optical device to illuminate each of the two chambers, the device comprising at least one laser capable of emitting a laser beam intended to interact with the precursors to form the core and the shell. The device further includes at least a shell precursor inlet channel, one end of which is in the form of a distribution chamber surrounding the communication channel between the two chambers of the reactor, said distribution chamber being further provided, on its inner periphery, with at least one opening leading inside said communication channel.

A positive electrode and a secondary battery including the same is disclosed herein. In some embodiments, a positive electrode includes a positive electrode current collector and a positive electrode mixture containing a positive electrode active material disposed thereon, the positive electrode active material includes a lithium transition metal oxide powder represented by chemical formula 1,

Li.sub.aNi.sub.xCo.sub.yM.sub.zO.sub.2-wA.sub.w  (1) M is at least one selected from the group consisting of Mn, Ti, Mg, Al, Zr, Mn and Ni, A is an oxygen-substituted halogen, and 1.00≤a≤1.05, 0.1≤x≤0.8, 0.1≤y≤0.8, 0.01≤z≤0.4, and 0≤w≤0.001, the powder having large particles which are secondary particles having an average particle diameter (D50) of 7 μm to 17 μm, and small particles which are single particles having average particle diameter (D50) of 2 μm to 7 μm, weight ratio of large particles to small particles is 5:5 to 9:1, and the positive electrode mixture has a porosity of 22% to 35%.

A carbon-containing alumina powder containing a carbon-containing alumina particle having a projected area equivalent circle diameter of 1 μm or more and 100 μm or less as determined by microscopy, wherein an average sphericity of the carbon-containing alumina particle is 0.85 or more, and a specific surface area is 0.05 m.sup.2/g or more and 1.0 m.sup.2/g or less, and a ratio B/A of a carbon content ratio B to a carbon content ratio A in the carbon-containing alumina powder calculated by using a specific measurement method is 0.20 or more and 0.90 or less.

Silica particles include a nitrogen-containing compound. When the volumes of pores having a diameter of 1 nm or more and 50 nm or less, the volumes being determined from a pore size distribution curve of the silica particles before and after the silica particles are baked at 350° C., the pore size distribution curve being obtained by nitrogen gas adsorption, are defined as A and B, respectively, B/A is 1.2 or more and 5 or less and B is 0.2 cm.sup.3/g or more and 3 cm.sup.3/g or less.