The cathode active material for a lithium secondary battery according to embodiments of the present invention includes lithium-transition metal composite oxide particles including a plurality of primary particles, and the lithium-transition metal composite oxide particles have a lithium-potassium-containing portion formed between the primary particles. Thereby, it is possible to improve life-span properties and capacity properties by preventing the layer structure deformation of the primary particles and removing residual lithium.

The present invention relates to a method of preparing a positive electrode active material for a lithium secondary battery, and more particularly, to a method of preparing a positive electrode active material for a lithium secondary battery, which is able to improve electrochemical properties and stability by controlling the specific surface area of a positive electrode active material.

A NaNiCl battery and a module using the same are provided. A NaNiCl battery according to the present invention include: a case that forms an exterior shape of the battery; and a beta alumina solid electrolyte (BASE) tube that is provided in the case and having a clover-shaped cross-section, wherein the case has a clover-shaped cross-section like the clover-shaped cross-section of the BASE tube to minimize a space between the case and the BASE tube.

A composite cathode active material for a lithium battery, the composite cathode active material including: a lithium composite oxide; and a coating layer disposed on at least a portion of the lithium composite oxide and including a composite including ZrP.sub.2O.sub.7 and LiZr.sub.2(PO.sub.4).sub.3, wherein the composite including ZrP.sub.2O.sub.7 and LiZr.sub.2(PO.sub.4).sub.3 is a reaction product of an acid treated a zirconium precursor, a phosphorus precursor, and the lithium composite oxide.

The present invention belongs to the field of materials, and relates to an environment-friendly precursor, a cathode material for a lithium-ion battery, and preparation methods thereof. The method for preparing an environment-friendly precursor provided in the present invention includes: subjecting a metal and/or a metal oxide, an oxidant, water, and a complexing agent to a chemical corrosion crystallization reaction at an electrical conductivity equal to or greater than 200 uS/cm, a redox potential ORP value equal to or less than 100 my, and a complexing agent concentration of 3-50 g/L. The precursor prepared by using the method provided in the present invention has advantages that no waste water is produced during dissolution and crystallization, and that water is constantly consumed, so that the purpose of environmental friendliness can be achieved. Moreover, the first charge and discharge efficiency of a lithium-ion battery can be effectively improved by means of the precursor.

Cathode material from exhausted lithium ion batteries are dissolved in a solution for extracting the useful elements Co (cobalt), Ni (nickel), Al (Aluminum) and Mn (manganese) to produce active cathode materials for new batteries. The solution includes compounds of desirable materials such as cobalt, nickel, aluminum and manganese dissolved as compounds from the exhausted cathode material of spent cells. Depending on a desired proportion, or ratio, of the desired materials, raw materials are added to the solution to achieve the desired ratio of the commingled compounds for the recycled cathode material for new cells. The desired materials precipitate out of solution without extensive heating or separation of the desired materials into individual compounds or elements. The resulting active cathode material has the predetermined ratio for use in new cells, and avoids high heat typically required to separate the useful elements because the desired materials remain commingled in solution.

A process is described for producing mixed oxide in particulate form, comprising cations of lithium and cations of at least two transition metals selected from the group consisting of nickel, cobalt, manganese, titanium, vanadium, chromium and iron, as are mixed oxides produced by this process.

The embodiments herein relate to electrochromic stacks, electrochromic devices, and methods and apparatus for making such stacks and devices. In various embodiments, an anodically coloring layer in an electrochromic stack or device is fabricated to include nickel-tungsten-niobium-oxide (NiWNbO). This material is particularly beneficial in that it is very transparent in its clear state.

A positive electrode active material for a lithium secondary battery, including secondary particles formed by aggregation of primary particles capable of being doped and undoped with lithium ions, said positive electrode active material having: an α-NaFeO.sub.2 type crystal structure represented by formula: Li[Li.sub.x(Ni.sub.aCo.sub.bMn.sub.cM.sub.d).sub.1-x]O.sub.2 (I), wherein 0≦x≦0.1, 0.7<a<1, 0<b<0.2, 0≦c<0.2, 0<d<0.1, a+b+c+d=1, and M is at least one metal element selected from the group consisting of Fe, Cr, Ti, Mg, Al, Zr, Ca, Sc, V, Cr, Cu, Zn, Ga, Ge, Sr, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In and Sn; and a crystallite size α/crystallite size β ratio (α/β) of 1.60 to 2.40, wherein the crystallite size α is within a peak region of 2θ=18.7±1° and the crystallite size β is within a peak region of 2θ=44.4±1°, each determined by a powder X-ray diffraction measurement using Cu-Kα radiation.

A composite cathode active material, includes a first metal oxide having a first layered crystal structure; and a second metal oxide having a second layered crystal structure, wherein the second metal oxide includes a layered double oxide (LDO). Also a cathode and a lithium battery including the composite cathode active material.