A method for producing a nickel cobalt complex hydroxide includes first crystallization of supplying a solution containing Ni, Co and Mn, a complex ion forming agent and a basic solution separately and simultaneously to one reaction vessel to obtain nickel cobalt complex hydroxide particles, and a second crystallization of, after the first crystallization, further supplying a solution containing nickel, cobalt, and manganese, a solution of a complex ion forming agent, a basic solution, and a solution containing said element M separately and simultaneously to the reaction vessel to crystallize a complex hydroxide particles containing nickel, cobalt, manganese and said element M on the nickel cobalt complex hydroxide particles crystallizing a complex hydroxide particles comprising Ni, Co, Mn and the element M on the nickel cobalt complex hydroxide particles.

There are provided processes for preparing a metal hydroxide comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium and aluminum, the process comprising: reacting a metal sulfate comprising (i) at least one metal chosen from nickel and cobalt and optionally (ii) at least one metal chosen from manganese, lithium and aluminum with lithium hydroxide, sodium hydroxide and/or potassium hydroxide and optionally a chelating agent in order to obtain a solid comprising the metal hydroxide and a liquid comprising lithium sulfate, sodium sulfate and/or potassium sulfate; separating the liquid and the solid from one another to obtain the metal hydroxide; submitting the liquid comprising lithium sulfate, sodium sulfate and/or potassium sulfate to an electromembrane process for converting the lithium sulfate, sodium sulfate and/or potassium sulfate into lithium hydroxide, sodium hydroxide and/or potassium hydroxide respectively; reusing the sodium hydroxide obtained by the electromembrane process for reacting with the metal sulfate; and reusing the lithium hydroxide obtained by the electromembrane process for reacting with the metal sulfate and/or with the metal hydroxide.

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.

Disclosed are a pre-lithiated lithium ion positive electrode material, a preparation method therefor and use thereof. The lithium ion positive electrode material has a chemical formula of Li.sub.2O/[A.sub.(3-x)Me.sub.x].sub.1/3-LiAO.sub.2, wherein A comprises M, and wherein M is at least one of Ni, Co, and Mn; and wherein Me is at least one of Ni, Mn, Al, Mg, Ti, Zr, Y, Mo, W, Na, Ce, Cr, Zn or Fe; and wherein 0 < × < 0.1. The material is co-doped with multiple elements, and these elements act synergistically to inhibit the irreversible phase change at a high voltage and improve the stability of the structure of a substrate. The spinel phase A.sub.(3-x)Me.sub.xO.sub.4 structure contains the doping elements, which work together to improve the interfacial activity of the material and introduce more electrochemically active sites.

A lithium cobalt metal oxide powder is disclosed in the present disclosure. The lithium cobalt metal oxide powder has a coating structure. The lithium cobalt metal oxide powder includes a lithium cobalt metal oxide matrix. The lithium cobalt metal oxide powder further includes a Co.sub.3O.sub.4 coating layer. A general formula of the lithium cobalt metal oxide powder is Li.sub.aCo.sub.1-x-yM.sub.xN.sub.yO.sub.2.Math.rCo.sub.3O.sub.4, wherein 0.002<r≤0.05, 1≤a≤1.1, 0<x≤0.02, 0≤y≤0.005, and a<1+3r; M is a doping element; and N is a coating element. A method for making the lithium cobalt metal oxide powder as described above and a method for determining a content of Co.sub.3O.sub.4 therein are further provided. The material made in the present disclosure has an excellent electrochemical performance.

The present disclosure relates to positive-electrode pre-lithiation agents. One example positive-electrode pre-lithiation agent includes a catalyst and a lithium-rich material, where the catalyst is an oxide positive-electrode active material, an intensity ratio of a crystal plane diffraction peak of the catalyst to a crystal plane diffraction peak of the catalyst is less than or equal to 2, the catalyst is configured to catalyze the lithium-rich material to decompose to release active lithium, and the lithium-rich material includes at least one of lithium oxide, lithium peroxide, lithium fluoride, lithium carbonate, lithium oxalate, or lithium acetate.

Provided are a sacrificial positive electrode material with a reduced gas generation amount and a method of preparing the same. The method includes calcinating a raw material mixture of lithium oxide (Li.sub.2O) and cobalt oxide (CoO) to prepare a lithium cobalt metal oxide, wherein the lithium oxide (Li.sub.2O) has an average particle size (D50) of 50 .Math.m or less, and the resulting sacrificial positive electrode material has an electrical conductivity of 1 × 10.sup.-4 S/cm or more. The method of preparing a sacrificial positive electrode material can reduce the generation of gas, particularly, oxygen (O.sub.2) gas, in an electrode assembly during charging of a battery by adjusting the electrical conductivity of the sacrificial positive electrode material within a specific range using lithium oxide that satisfies a specific size, and thus the stability and lifespan of the battery including the same can be effectively enhanced.

The invention belongs to the technical field of lithium ion battery cathode materials, and discloses a preparation method and application of nanosized lithium cobalt oxide cathode materials, comprising the following steps: mixing the carbonate solution with a dispersant, adding a cobalt salt solution to react, then aging, filtering, drying the filter residue to obtain a nano-CoCO.sub.3 powder, and then calcinating it to obtain a Co.sub.3O.sub.4 precursor; mixing the Co.sub.3O.sub.4 precursor with a lithium salt, and then sintering, cooling, pulverizing and sieving to obtain the nanosized lithium cobalt oxide cathode material. The main advantages of the present invention are that the nano-CoCO.sub.3 synthesis process is simple and easy to control, the process is short, no special temperature control is required, the pH value and other conditions are not required to be precisely controlled during the reaction process, and it is suitable for large-scale industrial production.

Compounds, particles, and cathode active materials that can be used in lithium ion batteries are described herein. Methods of making such compounds, powders, and cathode active materials are described.

A CoVO.sub.x composite electrode and method of making is described. The composite electrode comprises a substrate with an average 0.5-5 μm thick layer of CoVO.sub.x having pores with average diameters of 2-200 nm. The method of making the composite electrode involves contacting the substrate with an aerosol comprising a solvent, a cobalt complex, and a vanadium complex. The CoVO.sub.x composite electrode is capable of being used in an electrochemical cell for water oxidation.