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.

A cathode active material for lithium secondary batteries, a method of preparing the same, a cathode including the same, and a lithium secondary battery including the cathode are provided. The cathode active material includes nickel-based lithium metal oxide secondary particles each including a plurality of large primary particles, the nickel-based lithium metal oxide secondary particles having a hollow structure having pores therein, each of the plurality of large primary particles having a size of about 2 μm to about 6 μm, and each of the nickel-based lithium metal oxide secondary particles having a size of about 10 μm to about 18 μm; and a cobalt compound-containing coating layer on surfaces of the nickel-based lithium metal oxide secondary particles.

A positive electrode active material with high charge and discharge capacity is provided. A positive electrode active material with high charge and discharge voltage is provided. A power storage device that hardly deteriorates is provided. A highly safe power storage device is provided. A novel power storage device is provided. A positive electrode active material containing lithium, a plurality of transition metals, oxygen, and an impurity element. The positive electrode active material includes a first region including a surface portion and a second region provided inward from the first region, and the concentration of a transition metal is higher in the first region than in the second region. An impurity region is included between the first region and the second region.

A lithium cobalt-based positive electrode active material is provided. The lithium cobalt-based positive electrode active material includes a core portion including a lithium cobalt-based oxide represented by Formula 1 and a shell portion including a lithium cobalt-based oxide represented by Formula 2, wherein the lithium cobalt-based positive electrode active material includes 2500 ppm or more, preferably 3000 ppm or more of a doping element M based on the total weight of the positive electrode active material. An inflection point does not appear in a voltage profile measured during charging/discharging a secondary battery including the lithium cobalt-based positive electrode active material.

The present disclosure relates to the technical field of positive electrode lithium-supplementing additives of the lithium battery, and discloses a carbon-coated lithium-rich oxide composite material and a preparation method thereof. The method comprises the following steps: (1) mixing an iron source or a cobalt source with a lithium source, and sintering to obtain a lithium-rich oxide Li.sub.5FeO.sub.4 or Li.sub.6CoO.sub.4; wherein, a molar ratio of the lithium source to the iron source is 5-25:1, and a molar ratio of the lithium source to the cobalt source is 6-30:1; (2) crushing the lithium-rich oxide obtained in the step (1); and (3) mixing the lithium-rich oxide crushed in the step (2) with a carbon source, and sintering to obtain the carbon-coated lithium-rich oxide composite material. The carbon-coated lithium-rich oxide composite material prepared by the method of the present disclosure overcomes the insufficient conductivity of lithium-rich materials, and has good electrochemical properties, which is capable of effectively compensating for active lithium lost during the initial charge-discharge process of the lithium battery.

The present disclosure discloses a cathode composite material for a lithium-ion battery (LIB), and a preparation method thereof. The cathode composite material for an LIB is composed of a lithium-containing matrix and a three-layer coating layer coated on a surface of the matrix, where the three-layer coating layer includes a lithium-deficient matrix material layer, a lithium-deficient lithium cobalt phosphate (LCP) layer, and a cobalt phosphate layer in sequence from inside to outside. The cathode composite material of the present disclosure can reduce the oxidation of a highly-delithiated cathode material to an electrolyte under high voltage, and has a high energy density.

A process 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 comprises: reacting a metal sulfate comprising (i) at least one metal chosen from nickel and cobalt and optionally (iii) at least one metal chosen from manganese and aluminum with sodium hydroxide and optionally a chelating agent in order to obtain a solid comprising the metal hydroxide and a liquid comprising sodium sulfate; separating the liquid and the solid from one another to obtain the metal hydroxide; submitting the liquid comprising sodium sulfate to an electromembrane process for converting the sodium sulfate into sodium hydroxide; and reusing the sodium hydroxide obtained by the electromembrane process for reacting with the metal sulfate.

A lithium transition metal oxide, which is a lithium cobalt oxide containing a hetero-element, is capable of minimizing a side reaction with an electrolyte, thereby suppressing the generation of gas during charging and discharging of a lithium secondary battery is provided. The hetero-element includes a 4th period transition metal; and at least one selected from the group consisting of a group 2 element, a group 13 element, a group 14 element, a 5th period transition metal, and a 6th period transition metal. A positive electrode additive for a lithium secondary battery, and a lithium secondary battery are also provided.

A sacrificial positive electrode material, a positive electrode comprising the same, and a lithium secondary battery having the positive electrode are disclosed herein. In some embodiments, a sacrificial positive electrode material includes a lithium cobalt oxide represented by the following Chemical Formula 1, wherein the sacrificial positive electrode active material has a defect formation energy of metal (M) of −4.0 to −8.5 eV, calculated using density functional theory (DFT):

Li.sub.xCo.sub.(1-y)M.sub.yO.sub.4   [Chemical Formula 1]

M is at least one selected from the group consisting of Al, Fe, Zn, Ti, W, Mg, Ge and Si, pa x and y are 5≤x≤7 and 0.05≤y≤0.6. When the defect formation energy of the metal is controlled within a specific range, a high initial charging/discharging efficiency is realized during initial charging/discharging, and the amount of gas additionally generated at the later time of charging/discharging is reduced. Thus, stability and the charging/discharging performance of a battery is improved.

There is provided a method for collecting and reusing an active material from positive electrode scrap. The positive electrode active material reuse method of the present disclosure includes (a) thermally treating positive electrode scrap comprising a lithium cobalt oxide positive electrode active material layer on a current collector in air for thermal decomposition of a binder and a conductive material in the active material layer, to separate the current collector from the active material layer, and collecting an active material in the active material layer, (b) washing the collected active material with a lithium compound solution which is basic in an aqueous solution and drying, and (c) annealing the washed active material with an addition of a lithium precursor to obtain a reusable active material.