A producing method of a solution that contains lithium, at least one of a niobium complex and a titanium complex, and ammonia, wherein an amount of the ammonia in the solution is 0.3 mass % or less. The solution is suitable for forming a coating layer capable of improving battery characteristics of an active material in a battery.

The present disclosure provides a positive electrode active material which can impart an excellent low temperature output characteristic to a nonaqueous electrolyte secondary battery, and can suppress an increase in resistance after cycle charging and discharging. The positive electrode active material herein disclosed includes a core part including a lithium transition metal composite oxide, and a coating part including a titanium-containing compound on at least a partial surface of the core part. The coating part includes brookite type TiO.sub.2 and a lithium titanium (LiTi) composite oxide including lithium (Li) and titanium (Ti) as titanium-containing compounds, and at least part of titanium (Ti) of the titanium-containing compound is incorporated in a solid solution in the surface of the core part.

The disclosure discloses a method for preparing a high-voltage cathode material by body modification and regeneration of a waste lithium cobaltate material. The waste lithium cobaltate cathode material is calcined, and then measured; a lithium source, a magnesium source, nano-scale TiO.sub.2 and the waste lithium cobaltate cathode material powder are mixed to obtain a mixture, placed in a ball milling tank containing absolute ethanol, and the resulting mixture is ball milled, and then dried to obtain a mixed powder; the mixed powder is calcined to obtain a magnesium-titanium co-doped regenerated lithium cobaltate cathode material; the magnesium-titanium co-doped regenerated lithium cobaltate cathode material is added into a mixed solution obtained by ultrasonically mixing absolute ethanol with the aluminum source, and then heated and stirred continually until the solvent evaporates to obtain a residue; the residue is calcined to obtain an aluminum-coated magnesium-titanium co-doped regenerated lithium cobaltate cathode material.

Disclosed is a process for coating onto a substrate, including preparing a precursor having a general formula Q.sub.m/nMO.sub.xF.sub.y by a reaction M(OH).sub.x+yHF+m/nQ(OH).sub.n.fwdarw.Q.sup.n+.sub.m/n(MO.sub.xF.sub.y).sup.m−, wherein Q is an onium ion, selected from quaternary alkyl ammonium, quaternary alkyl phosphonium and trialkylsulfonium; M is a metal capable of forming an oxofluorometallate, where M may further comprise one or more additional metal, metalloid, and one or more of phosphorus (P), sulfur (S) and selenium (Se), iodine (I), and arsenic (As) or a combination thereof, and x>0, y>0, m≥1, n≥1; combining the precursor with a lithium ion source and with the substrate, and mixing to form a coating composition comprising a lithium oxofluorometallate having a general formula Li.sub.mMO.sub.xF.sub.y on the substrate. Further disclosed is a core-shell electrode active material including a core capable of intercalating and deintercalating lithium coated with the lithium oxofluorometallate having the general formula Li.sub.mMO.sub.xF.sub.y.

Provided is a composition comprising: (a) a principal phase that is provided by a layered mixed metal oxide having a rocksalt structure belonging to the R-3m space group; the layered mixed metal oxide comprising the following component elements: 45 to 55 atomic % lithium; 20 to 55 atomic % of one or more transition metals selected from the group consisting of chromium, manganese, iron, nickel, cobalt, and combinations thereof; and 0 to 25 atomic % of one or more additional dopant elements selected from the group consisting of: magnesium, calcium, strontium, titanium, zirconium, vanadium, copper, ruthenium, zinc, molybdenum, boron, aluminium, gallium, tin, lead, bismuth, lanthanum, cerium, gadolinium and europium; wherein said atomic % is expressed as a % of total atoms of said layered oxide, excluding oxygen; (b) a minor phase that is provided by a metal oxide that does not have the crystal structure of the layered mixed metal oxide, the minor phase comprising one or more of the transition metals contained in the layered mixed metal oxide, the transition metals being selected from the group consisting of chromium, manganese, iron, nickel, and cobalt. Methods of making the composition and electrodes and cells, especially solid-state batteries, containing the composition are also provided. The rough morphology of the crystals confers advantages compared with smoother crystals of similar chemical composition, particularly in solid-state batteries.

A method for forming a Group IV transition metal containing film comprises a) exposing a substrate to a vapor of a Group IV transition metal containing film forming composition; b) exposing the substrate to a co-reactant; and c) repeating the steps of a) and b) until a desired thickness of the Group IV transition metal containing film is deposited on the substrate using a vapor deposition process,

Provided is a positive electrode active material for a lithium ion secondary battery having favorable cycle characteristics and high capacity. A covering layer containing aluminum and a covering layer containing magnesium are provided on a superficial portion of the positive electrode active material. The covering layer containing magnesium exists in a region closer to a particle surface than the covering layer containing aluminum is. The covering layer containing aluminum can be formed by a sol-gel method using an aluminum alkoxide. The covering layer containing magnesium can be formed as follows: magnesium and fluorine are mixed as a starting material and then subjected to heating after the sol-gel step, so that magnesium is segregated.

A positive electrode active material includes powder of composite particles including a lithium transition metal composite oxide having a lamellar rock-salt structure and a spinel phase. The spinel phase includes an oxide including lithium and at least a first element X1 selected from the group consisting of magnesium, aluminum, titanium, manganese, yttrium, zirconium, molybdenum, and tungsten, and the lithium transition metal composite oxide includes nickel or cobalt and the first element X1.

The present invention relates to a lithium secondary battery. The lithium secondary battery includes a positive electrode including a positive active material; a negative electrode including a negative active material; and an electrolyte including a non-aqueous organic solvent, a lithium salt, and an additive including a compound represented by Chemical Formula 1. The negative active material includes Si at about 0.1 wt % to about 32 wt % in amount based on a total weight of the negative active material. ##STR00001## wherein, in Chemical Formula 1, A is a substituted or unsubstituted aliphatic chain or (—C.sub.2H.sub.4—O—C.sub.2H.sub.4-)n, and n is an integer from 1 to 10.

The present invention relates to a positive electrode additive for a lithium secondary battery, a manufacturing method thereof, a positive electrode for a lithium secondary battery including the same, and a lithium secondary battery including the same.

The positive electrode additive for a lithium secondary battery according to an exemplary embodiment of the present invention is represented by Chemical Formula 1 below.

Li.sub.6xCo.sub.1-yM.sub.yO.sub.4  [Chemical Formula 1] (In the Chemical Formula 1, 0.9≤x≤1.1, 0<y≤0.1, My=B.sub.aW.sub.b, 0≤a≤0.1, 0≤b≤0.1, and, a and b are not simultaneously 0.)

Another positive electrode additive for a lithium secondary battery according to an exemplary embodiment of the present invention includes a core represented by Chemical Formula 2 below; and a coating layer comprising at least one of boron (B) and tungsten (W).

Li.sub.6xCoO.sub.4  [Chemical Formula 2] (In the Chemical Formula 2, 0.9≤x≤1.1.)