A secondary battery with favorable cycle performance is provided. Alternatively, a secondary battery with higher capacity is provided. A positive electrode active material layer including a first graphene layer, a second graphene layer, and a positive electrode active material. The first graphene layer includes a first region covering the positive electrode active material. The second graphene layer includes a second region covering the positive electrode active material and a third region overlapping with the first region. The first region includes a plane positioned between the positive electrode active material and the third region and formed of arranged six-membered carbon rings. The positive electrode active material includes a fourth region with a layered rock-salt structure. A lithium layer with a layered rock-salt structure included in the fourth region is substantially perpendicular to the plane formed of six-membered carbon rings and included in the second region.

A positive electrode active material for an all-solid-state lithium ion secondary battery, containing: a lithium-metal composite oxide particle having a niobium solid solution layer and a center other than the niobium solid solution layer; and a coating layer coating at least a part of a surface of the lithium-metal composite oxide particle and formed of a compound containing lithium and niobium, an average thickness of the coating layer is 2 nm or more and 1 μm or less, and an average thickness of the niobium solid solution layer is 0.5 nm or more and 20 nm or less.

Provided are enhanced MXene materials made from MAX-phase precursors that comprise an excess of metal A. The resultant enhanced MXenes exhibit improved stability over periods of days and months, particularly when stored in aqueous media.

Disclosed are a multi-wall carbon nanotube (MWCNT) formed using arc discharge and a method for manufacturing the same. The carbon source of the anode and boron that is the doping source, are evaporated through arc discharge and then deposited on the surface of the cathode to form MWCNTs, and boron is evenly distributed in the multi-walls of the MWCNTs. Therefore, the outer diameter of the MWCNT is reduced, high thermal stability is secured, and the effect of improving the field emission characteristics can be obtained.

Disclosed are a method for manufacturing an electrode, an electrode manufactured thereby, a membrane-electrode assembly including the electrode, and a fuel cell containing the membrane-electrode assembly. The method includes the steps of: preparing an electrode forming composition by mixing a catalyst with an ionomer; applying a low-frequency acoustic energy to the electrode forming composition to perform resonant vibratory mixing so as to coat the ionomer on the surface of the catalyst; and coating the electrode forming composition to manufacture an electrode.

The invention described herein provides a dry graphene powder composition comprising pristine graphene flakes, wherein the pristine graphene flakes are non-covalently functionalised with polymeric amphiphilic molecules and wherein the dry graphene powder composition is capable of forming a stable homogeneous dispersion in aqueous or alcoholic media, in the absence of free dispersants or stabilizers, as well as methods for producing same, and the use thereof in graphene inks, for 2D and 3D printing, for production of flexible circuits, electrodes, electrocatalysts, for fabrication of nanocomposites and for wet-spinning of pristine graphene fibers.

Preparing MAX phase structures includes forming a gel including a transition metal M, a Group 3A or Group 4A metal or semimetal A, and an acidic chelating agent or gelling agent X. X includes one or both of carbon and nitrogen. Preparing the MAX phase structures further includes shaping the gel to yield a shaped gel and heating the shaped gel to yield carbonaceous MAX phase structures with a composition represented by M.sub.n+1AX.sub.n, wherein n is 1, 2, 3, or 4. The MAX phase structures can be thick films, microspheres, or microwires.

There are provided a new type of crystal laminate of an alkaline earth metal titanate having improved catalytic activity, and a method for producing the same. The crystal laminate is provided having a crystal of the alkaline earth metal titanate as a constitutional unit, wherein the crystal being the constitutional unit is a cubic crystal, a tetragonal crystal or an orthorhombic crystal; the crystal being the constitutional unit has a primary particle diameter of 500 nm or less; and the crystal is layered with an orientation in a {100} plane direction thereof.

Exemplary embodiments of positive electrode active materials in the form of single particles, and a method of preparing each of them, are provided. The single particles of the exemplary embodiments include single particles of a nickel-based lithium composite metal oxide, having a plurality of crystal grains, each having a size of 180 nm to 300 nm, as analyzed by a Cu Kα X-ray (X-rα). The single particles include a metal doped in the crystal lattice thereof. One embodiment includes a surface coating. The total content of the metal doped in the crystal lattice thereof and the metal of the metal oxide coated on the surface thereof is controlled in the range of 2500 ppm to 6000 ppm.

Disclosed herein are modified zeolites and methods for making modified zeolites. In one or more embodiments disclosed herein, a modified zeolite may include a microporous framework including a plurality of micropores having diameters of less than or equal to 2 nm. The microporous framework includes at least silicon atoms and oxygen atoms. The modified zeolite may further include organometallic moieties each bonded to bridging oxygen atoms. The organometallic moieties include a hafnium atom. The hafnium atom is bonded to a bridging oxygen atom, and bridging oxygen atom bridges the hafnium atom of the organometallic moiety and a silicon atom of the microporous framework.