A positive electrode active material in which a discharge capacity decrease due to charge and discharge cycles is suppressed and a secondary battery including the positive electrode active material are provided. A positive electrode active material in which a change in a crystal structure, e.g., a shift in CoO.sub.2 layers is small between a discharged state and a high-voltage charged state is provided. For example, a positive electrode active material that has a layered rock-salt crystal structure belonging to the space group R-3m in a discharged state and a crystal structure belonging to the space group P2/m in a charged state where x in Li.sub.xCoO.sub.2 is greater than 0.1 and less than or equal to 0.24 is provided. When the positive electrode active material is analyzed by powder X-ray diffraction, a diffraction pattern has at least diffraction peaks at 2θ of 19.47±0.10° and 2θ of 45.62±0.05°.

The present invention relates to a cathode active material, and a lithium secondary battery comprising the same, the present invention provides a cathode active material, represented by the following Chemical Formula 1, wherein I003/I104 ratio is 1.6 or more, and R-factor value represented by the following Formula 1 is 0.40 to 0.44, and c-axis lattice constant (c) and a-axis lattice constant (a) satisfy 3(a)+5.555≤(c)≤3(a)+5.580:
R-factor=(I102+I006)/(I101)  Formula 1 wherein I003, I006, I101, I102, and I104 are the intensity of diffraction peaks on the (003), (006), (101), (102), and (104) planes by X-ray diffraction analysis using CuKα-rays,
Li.sub.α[(Ni.sub.xCo.sub.y).sub.1-βA.sub.β]O.sub.z  Chemical Formula 1 in the Chemical Formula 1, 0.95≤α≤1.1, 0.75≤x≤0.95, 0.03≤y≤0.25, 0<β≤0.2, and 1.9≤z≤2.1, and A is a dopant metal element, and the average oxidation number N of A is 3.05≤N≤3.35.

An aluminum nitride film includes a polycrystalline aluminum nitride. A withstand voltage of the aluminum nitride film is 100 kV/mm or more.

A positive electrode active material, and a positive electrode and a lithium secondary battery including the same are disclosed herein. In some embodiments, a positive electrode active material includes a lithium composite transition metal oxide containing nickel, cobalt, and manganese and having a nickel content for 60 mol % or more, based on metals (M) excluding lithium, and is in the form of single particles having an average particle diameter (D.sub.50) of 1 to 10 μm, wherein a 100-nm region extending from the surface toward the center of a single particle has crystal structures of a Fd3M and a Fm3m space group, and a phase ratio is 0.2 to 0.7, which is a ratio of a first portion of a maximum straight length of the 100-nm region occupied by the crystal structure of the Fd3M space group to a second portion occupied by the crystal structure of the Fm3m space group.

An object is to provide an electrode active material having a novel structure, said electrode active material enabling Li.sub.2S to be used as an electrode. The problem is solved by a solid solution with an antifluorite crystal structure comprising Li, Cu, and S as main constituents.

An oxide includes a compound represented by Formula 1, a compound represented by Formula 2, or a combination thereof:
Li.sub.1−x+y−zTa.sub.2−xM.sub.xP.sub.1−yQ.sub.yO.sub.8−zX.sub.z  Formula 1
wherein, in Formula 1, M is an element having an oxidation number of 5+ or 6+, Q is an element having an oxidation number of 4+, X is a halogen atom, a pseudohalogen, or a combination thereof,
0≤x<0.6, 0≤y<1, and 0≤z<1, wherein x and y are not 0 at the same time,
Li.sub.1−x+yTa.sub.2−xM.sub.xP.sub.1−yQ.sub.yO.sub.8.zLiX  Formula 2
wherein, in Formula 2, M is an element having an oxidation number of 5+ or 6+, Q is an element having an oxidation number of 4+, X is a halogen atom, a pseudohalogen or a combination thereof, 0≤x<0.6, 0≤y<1, and 0≤z<1, wherein x and y are not 0 at the same time, and
wherein in Formulas 1 and 2, M, Q, x, y, and z are independently selected.

The present disclosure relates to an anode electrode active material for a secondary battery containing nickel cobalt molybdenum oxide, an anode electrode for a secondary battery including the same, a secondary battery including the anode electrode for a secondary battery, and a method for manufacturing the same. The novel anode electrode material for a sodium secondary battery containing nickel cobalt molybdenum oxide according to the present disclosure allows intercalation/deintercalation reaction of sodium ion during charge/discharge and does not undergo significant volume change during the intercalation reaction because structure is maintained stably during repeated charge/discharge. As a result, electrode damage and electric short circuit are decreased and, thus, improved electrochemical characteristics can be achieved in long-life and high-rate capability.

The invention relates to a millimeter-sized bulk spa amorphous carbon material and a method of preparing the same, and the method comprises a step of performing a high-temperature and high-pressure (HTHP) treatment on C.sub.60 powder at a temperature of 450-1100° C., preferably 700-1000° C., more preferably 900-1000° C., and most preferably 1000° C., and a pressure of 20-37 GPa, preferably 20-30 GPa, and most preferably 27 GPa, so as to obtain the millimeter-sized bulk sp.sup.3 amorphous carbon material. The sp.sup.3 carbon content in the amorphous carbon material is adjustable by changing the temperature and pressure conditions, so that the sp.sup.3 content is greater than 80%, and the sp.sup.3 content of high-quality samples is close to 100%. The optical band gap and thermal conductivity of the series of amorphous carbon materials can be effectively adjusted. The obtained series of amorphous carbon materials have ultra-high hardnesses, high thermal conductivities, adjustable band gaps (1.90-2.79 eV) which exceed the ranges of the band gaps of amorphous silicon and germanium. As a result, a new space is opened up for the application of amorphous materials.

The present disclosure is directed to large-pore germanosilicate compositions designated CIT-13/OH and CIT-14/IST, the two large-pore germanosilicate each having a three-dimensional framework with 10- and 14-membered ring channels and 8- and 12-membered ring channels, respectively. The disclosure also sets forth methods for converting the former to the latter under conditions consistent with an inverse sigma transformation. Uses of the large-pore germanosilicate compositions are also disclosed.

A positive electrode active material, method of making the same, and positive electrode and lithium secondary battery include the same are disclosed herein. In some embodiments, a positive electrode active material in a form of single particles, includes a lithium transition metal oxide having nickel (Ni) in an amount greater than 50 mol % based on a total number of moles of transition metals excluding lithium, wherein a single particle has a region of 50 nm or less from a surface of the single particle along a center direction, and wherein a structure belonging to space group FD3-M and a structure belonging to space group Fm3m are formed in the region, and wherein a generation rate of fine powder having an average particle diameter (D.sub.50) of 1 μm or less is in a range of 5% to 30% when the positive electrode active material is rolled at 650 kgf/cm.sup.2.