Bandgap-tunable perovskite compositions are provided having the formula CsPb(A).sub.xB.sub.y).sub.3, wherein A and B are each a halogen. The mixed halide perovskite composition has a morphology which suppresses phase segregation to stabilize a tuned bandgap of the mixed halide perovskite composition. For example, the perovskite may be in the form of nanocrystals embedded in a non-perovskite matrix, which, for example, may have the formula Cs.sub.4Pb(A).sub.xB.sub.y)6, wherein A and B are each a halogen. Solar cells and light-emitting diodes comprising the mixed perovskite compositions are also provided.

This application describes electrode materials and methods of producing them, the materials containing particles having a core-shell structure, wherein the shell of the core-shell particles comprises a polymer, the polymer being grafted on the surface of the core particle by covalent bonds. Electrodes and electrochemical cells containing these electrode materials are also contemplated, as well as their use.

The present invention relates to a method for producing boron nitride nanostructures, the method comprising subjecting boron nitride precursor material to lamp ablation within an adiabatic radiative shielding environment. The nanostructures produced may include nano-onion structures. The boron nitride precursor material subjected to lamp ablation may include amorphous boron nitride, hexagonal boron nitride, cubic boron nitride, wurtzite boron nitride or a combination of two or more thereof.

A method for producing a carbon nanomaterial (CNM) product comprises: heating an electrolyte media to obtain a molten electrolyte media; positioning the molten electrolyte media between an anode and a cathode of an electrolytic cell, in which the anode comprises a noble metal and the cathode comprises copper and nickel; introducing a source of carbon into the electrolytic cell; introducing a nickel-containing additive into the electrolyte media before the step of heating or introducing the nickel-containing additive into the molten electrolyte media, in which the iron-free additive is added in an amount of between 0.05 wt % and 2 wt %, relative to the amount of the electrolyte media or the molten electrolyte media; applying an electrical current to the cathode and the anode in the electrolytic cell; and collecting the CNM product from the cathode.

Disclosed is a method of increasing the capacity of an O2 type positive electrode active material. The method of manufacturing a positive electrode active material according to the present disclosure comprises firing a precursor containing Na and transition metal elements, followed by cooling to obtain a Na containing transition-metal oxide having a P2 type structure; and replacing at least a portion of Na of the Na containing transition-metal oxide with Li by ion-exchange to obtain a positive electrode active material having an O2 type structure, wherein after firing the precursor, the cooling rate from 250? C. to cooling end-temperature is 20? C./min or higher.

A polycrystalline material having low mechanical strain is provided. The polycrystalline material includes one or multiple layers of a first type and one or multiple layers of a second type. The layers of the first type and the layers of the second type each include at least one polycrystalline material component. The layers of the first type have a smaller average crystal grain size than the layers of the second type, a layer of the first type and a layer of the second type being situated, at least in part, one above the other in an alternating sequence, and it being the case for the transition between the layers of the first type and the layers of the second type to be abrupt or continuous.

A magnetic -form iron oxide nanopowder is a novel magnetic iron oxide nanopowder having magnetic polarization and spontaneous electric polarization and having physical properties similar to those of half-metals; and a process produces the magnetic nanopowder. The magnetic powder has a composition represented by Fe.sub.2O.sub.3 and has a crystal structure belonging to the monoclinic system.

Provided is a complex oxide that has a high hydrogen content, contains almost no impurity phase, and is suitable for proton conductivity. The complex oxide is represented by a chemical formula Li.sub.7-xH.sub.xLa.sub.3M.sub.2O.sub.12 (M represents Zr and/or Hf, and 3.2<x7) and is a single phase of a garnet type structure belonging to a cubic system. A method for producing the complex oxide includes an exchange step of bringing a raw material complex oxide represented by a chemical formula Li.sub.7-xH.sub.xLa.sub.3M.sub.2O.sub.12 (M represents Zr and/or Hf, and 0x3.2) and a compound having a hydroxy group or a carboxyl group into contact with each other to exchange at least some of lithium of the raw material complex oxide and hydrogen of the compound having a hydroxy group or a carboxyl group.

The cathode active material for a non-aqueous electrolyte secondary battery according to one exemplary embodiment of the present invention includes a lithium-transition metal compound oxide containing, relative to a total molar amount of metallic elements except for Li, no less than 90 mol % at least one metallic element selected from Ni, Mn, Fe, and Al. The lithium-transition metal compound oxide comprises particles having a minor axis diameter of 0.5-6.0 ?m, the particles having 2-10 crystal planes therein.

Disclosed is a positive electrode active material particle having an O2-type structure and having excellent rate characteristics and capacity. The positive electrode active material particle of the present disclosure has an O2-type structure, has a chemical composition represented by Li.sub.aNa.sub.bMn.sub.x?pNi.sub.y?qCo.sub.z?rM.sub.p+q+rO.sub.2, wherein 1.0<a<1.30; 0?b?0.20; x+y+z=1; and 0?p+q+r?0.15, and M is at least one element selected from B, Mg, Al, K, Ca, Ti, V, Cr, Fe, Cu, Zn, Ga, Ge, Sr, Y, Zr, Nb, Mo, and W, and is spherical.