The present disclosure relates to the technical field of positive electrode lithium-supplementing additives of the lithium battery, and discloses a carbon-coated lithium-rich oxide composite material and a preparation method thereof. The method comprises the following steps: (1) mixing an iron source or a cobalt source with a lithium source, and sintering to obtain a lithium-rich oxide Li.sub.5FeO.sub.4 or Li.sub.6CoO.sub.4; wherein, a molar ratio of the lithium source to the iron source is 5-25:1, and a molar ratio of the lithium source to the cobalt source is 6-30:1; (2) crushing the lithium-rich oxide obtained in the step (1); and (3) mixing the lithium-rich oxide crushed in the step (2) with a carbon source, and sintering to obtain the carbon-coated lithium-rich oxide composite material. The carbon-coated lithium-rich oxide composite material prepared by the method of the present disclosure overcomes the insufficient conductivity of lithium-rich materials, and has good electrochemical properties, which is capable of effectively compensating for active lithium lost during the initial charge-discharge process of the lithium battery.

The present disclosure discloses a cathode composite material for a lithium-ion battery (LIB), and a preparation method thereof. The cathode composite material for an LIB is composed of a lithium-containing matrix and a three-layer coating layer coated on a surface of the matrix, where the three-layer coating layer includes a lithium-deficient matrix material layer, a lithium-deficient lithium cobalt phosphate (LCP) layer, and a cobalt phosphate layer in sequence from inside to outside. The cathode composite material of the present disclosure can reduce the oxidation of a highly-delithiated cathode material to an electrolyte under high voltage, and has a high energy density.

A titanium sulfide (TiS) nanomaterial and a composite material thereof for wave absorption are disclosed. The TiS nanomaterial is in a form of dispersed micro-particles which are bulks formed by stacking two-dimensional nano-sheets. The TiS nanomaterial is a bulk formed by stacking two-dimensional nano-sheets, thereby having a laminated structure that improves the wave absorption effect. In addition, experimental results demonstrate that the TiS nanomaterial with a dose of 40 wt% has the most excellent wave absorption performance, with a minimum reflection loss up to -47.4 dB, an effective absorption bandwidth of 5.9 GHz and an absorption peak frequency of 6.8 GHz, which are superior to those of existing two-dimensional bulk materials. One of reasons for the excellent wave absorption performance of the TiS nanomaterial may be because the laminated micro-morphology of TiS results in the electromagnetic wave refraction loss.

A method of recovering an active material from a positive electrode scrap and reusing the active material is provided. The method of reusing a positive electrode active material includes (a) thermally treating a positive electrode scrap comprising an active material layer on a current collector in air for thermal decomposition of a binder and a conductive material in the active material layer, to separate the current collector from the active material layer, and collecting an active material in the active material layer; (b) washing the active material collected from the step (a) with a cleaning solution; and (c) annealing the active material washed from the step (b) with an addition of a lithium precursor to obtain a reusable active material, wherein a molar ratio of lithium to other metals in the active material after the thermal treatment step (a) or a molar ratio of lithium to other metals in the active material after the washing step (b) has a decreased range of 20% or less when compared with a molar ratio of lithium to other metals in the positive electrode scrap before the thermal treatment step (a).

Composite nanoparticle compositions and associated nanoparticle assemblies are described herein which, in some embodiments, exhibit enhancements to one or more thermoelectric properties including increases in electrical conductivity and/or Seebeck coefficient and/or decreases in thermal conductivity. In one aspect, a composite nanoparticle composition comprises a semiconductor nanoparticle including a front face and a back face and sidewalls extending between the front and back faces. Metallic nanoparticles are bonded to at least one of the sidewalls establishing a metal-semiconductor junction.

The present disclosure provides a quantum dot particle with passivation layer, which mainly includes a one quantum dot (QD) particle, a first-passivation layer and a second-passivation layer, wherein the first-passivation layer is disposed on a surface of the QD particle, and the second-passivation layer is disposed on a surface of the first-passivation layer. A precursor chosen for forming the first-passivation layer does not cause damage to the QD particle. A precursor of the second-passivation layer includes a composition of trimethylaluminum (TMA) and water, or TMA and ozone, wherein a density of the second-passivation layer is greater than that of the first-passivation layer. The precursor of the second-passivation layer is kept out by the first-passivation layer, such that to prevent the precursor of the second-passivation layer from contacting the QD particle and causing deterioration thereto, and hence to improve a life cycle of the QD particle.

A positive active material made of carbon-coated lithium iron phosphate includes a lithium iron phosphate substrate, and a carbon coating layer on a surface of the substrate. The lithium iron phosphate substrate has a general structural formula LiFe.sub.1-aM.sub.aPO.sub.4, where M is at least one selected from Cu, Mn, Cr, Zn, Pb, Ca, Co, Ni, Sr, Nb, or Ti, and 0≤a≤0.01. A carbon coating factor of the carbon-coated lithium iron phosphate,

[00001]$\eta =\frac{\mathrm{BET}1}{\mathrm{BET}2},$

satisfies 0.81≤η≤0.95, where BET1 denotes a specific surface area of mesopore and macropore structures in the carbon-coated lithium iron phosphate, and BET2 denotes a total specific surface area of the carbon-coated lithium iron phosphate.

A ceramic powder material containing a garnet-type compound containing Li, wherein the ceramic powder material has a pore volume of 0.4 mL/g or more and 1.0 mL/g or less.

A quantum dot device and an electronic device including the device are provided. The quantum dot device includes a first electrode and a second electrode, a quantum dot layer disposed between the first electrode and the second electrode, and a hole auxiliary layer disposed between the quantum dot layer and the first electrode, wherein the hole auxiliary layer includes nickel oxide and a self-assembled monolayer disposed between the hole auxiliary layer and the quantum dot layer, the self-assembled monolayer including an organic compound represented by Chemical Formula 1.

A method for obtaining at least one particle, including: (a) preparing solution A including at least one precursor of at least one of Si, B, P, Ge, As, Al, Fe, Ti, Zr, Ni, Zn, Ca, Na, Ba, K, Mg, Pb, Ag, V, Te, Mn, Ir, Sc, Nb, Sn, Ce, Be, Ta, S, Se, N, F, and Cl; (b) preparing aqueous solution B; (c) forming droplets of solution A; (d) forming droplets of solution B; (e) mixing droplets; (f) dispersing mixed droplets in a gas flow; (g) heating dispersed droplets to obtain the at least one particle; (h) cooling the at least one particle; and (i) separating and collecting the at least one particle. The aqueous solution is acidic, neutral, or basic. In step (a) and/or step (b) at least one colloidal suspension of a plurality of nanoparticles is mixed with the solution. Also, a device for implementing the method.