The present disclosure is directed to using MXene compositions as templates for the deposition of oriented perovskite films, and compositions derived from such methods. Certain specific embodiments include methods preparing an oriented perovskite, perovskite-type, or perovskite-like film, the methods comprising: (a) depositing at least one perovskite, perovskite-type, or perovskite-like composition or precursor composition using chemical vapor deposition (CVD), physical vapor deposition (PVD), or atomic layer deposition (ALD) onto a film or layer of a MXene composition supported on a substrate to form a layered composition or precursor composition; and either (b) (1) heat treating or annealing the layered precursor composition to form a layered perovskite-type structure comprising at least one oriented perovskite, perovskite-type, or perovskite-like composition; or (2) annealing the layered composition; or (3) both (1) and (2).

Provided are electrochemically active secondary particles that provide excellent capacity and improved cycle life. The particles are characterized by selectively enriched grain boundaries where the grain boundaries are enriched with Al and Co. The enrichment with Al reduces impedance generation during cycling thereby improving capacity and cycle life. Also provided are methods of forming electrochemically active materials, as well as electrodes and electrochemical cells employing the secondary particles.

Provided are electrochemical cells that include as a cathode active material within the cathode of the cell secondary particles that provide excellent capacity and improved cycle life. The particles are characterized by grain boundaries between adjacent crystallites of the plurality of crystallites and comprising a second composition having a layered -NaFeO.sub.2-type structure, a cubic structure, a spinel structure, or a combination thereof, wherein the electrochemically active cathode active material has an initial discharge capacity of 180 mAh/g or greater; and wherein the electrochemical cell has an impedance growth at 4.2V less than 50% for greater than 100 cycles at 45 C.

The present disclosure is directed to compositions comprising at least one layer having first and second surfaces, each layer comprising: a substantially two-dimensional array of crystal cells, each crystal cell having an empirical formula of M.sub.2M.sub.nX.sub.n+1, such that each X is positioned within an octahedral array of M and M; wherein M and M each comprise different Group IIIB, IVB, VB, or VIB metals; each X is C, N, or a combination thereof; n=1 or 2; and wherein the M atoms are substantially present as two-dimensional outer arrays of atoms within the two-dimensional array of crystal cells; the M atoms are substantially present as two-dimensional inner arrays of atoms within the two-dimensional array of crystal cells; and the two dimensional inner arrays of M atoms are sandwiched between the two-dimensional outer arrays of M atoms within the two-dimensional array of crystal cells.

The present invention discloses a selenium-doped MXene composite nano-material and a preparation method thereof, comprising the following steps: (1) adding MXene and an organic selenium source into a dispersant, and stirring to prepare a dispersion with a concentration of 1 mg/ml to 100 mg/ml; (2) transferring the dispersion into a reaction kettle, then heating, reacting, and then naturally cooling to a room temperature; (3) washing the product obtained in the step (2) with a cleaning agent, then centrifuging to collect a precipitate, and drying the precipitate under vacuum; and (4) placing the sample obtained in the step (3) into a tubular furnace for calcination, introducing protective gas, heating, and then cooling to a room temperature to obtain the selenium-doped MXene composite nano-material. The material prepared by the present invention has high specific surface area, good electrical conductivity, cycle stability performance, rate performance and high theoretical specific capacity.

An aluminosilicate zeolite comprising at least 90% phase pure AEI zeolite crystals, the crystals having a plate-shaped morphology. In embodiments, at least 50% of the crystals have at least one ratio in at least one pair of dimensions in the range from 3:1 to 20:1, and thickness of 30-100 nm. A process of making the AEI zeolite comprising reacting an oxide of silicon, faujasite, a quaternary ammonium compound comprising 2,4,4,6-tetramethylmorpholinium cation, alkali metal hydroxide and water at at least 100 C to form crystals of a zeolite having an AEI framework. A crystalline AEI zeolite having pores comprising a 2,4,4,6-tetramethylmorpholinium, cation. The zeolite may comprise at least 90% phase pure AEI zeolite with the 2,4,4,6-tetramethylmorpholinium cation within pores of the zeolite. In some embodiments the zeolite comprises crystals having a plate-shaped morphology and with the 2,4,4,6-tetramethylmorpholinium cation within pores of the AEI zeolite.

A positive electrode active material for a nonaqueous electrolyte secondary battery includes particles of a lithium-transition metal composite oxide that contains nickel in the composition thereof and has a layered structure. The particles have an average particle size D.sub.SEM based on electron microscopic observation in a range of 1 m to 7 m in which a ratio D.sub.50/D.sub.SEM of a 50% particle size D.sub.50 in volume-based cumulative particle size distribution to the average particle size based on electron microscopic observation is in a range of 1 to 4, and a ratio D.sub.90/D.sub.10 of a 90% particle size D.sub.90 to a 10% particle size D.sub.10 in volume-based cumulative particle size distribution is 4 or less.

The present disclosure generally relates to compositions comprising substrate-free crystalline 2D bismuthene, and the method of making and using the substrate-free crystalline 2D bismuthene.

A single-step, in situ bipolar exfoliation system, and methods for exfoliations of multi-layer bulk black phosphorous into single-layer (two-dimensional), few-layer, or even nano-platelets phosphorene are provided. The bipolar exfoliation system can include: a first driving electrode; a second driving electrode electrically connected to the first driving electrode through an external power supply; at least one bipolar electrode comprising multi-layer bulk black phosphorous; and a solvent in physical contact with the first driving electrode, the second driving electrode, and the at least one bipolar electrode. The system can be configured such that the electric conditions between the first and second driving electrodes can be used to turn one end of the at least one bipolar electrode into an anodic pole and the other end of the at least one bipolar electrode into a cathodic pole such that the multi-layer black phosphorous is exfoliated into the single-layer, few-layer, or nano-platelets phosphorene.

The present invention provides a method capable of producing hexagonal plate-shaped zinc oxide having a small thickness and a small variation in the particle size. The present invention relates to a method for producing hexagonal plate-shaped zinc oxide, the method including: a step (1) of preparing a slurry mixture containing starting particulate zinc oxide, a zinc acetate solution, and a chloride; and a step (2) of heat aging the slurry mixture obtained in the step (1) at 60 C. to 100 C.