Lithium nickel-based composite oxide as a positive electrode active material for a rechargeable lithium-ion battery

Abstract

The present invention relates to a positive electrode active material suitable for use in electric vehicles (EVs) and hybrid electric vehicles (HEVs), the positive electrode active material comprising lithium transition metal-based oxide particles containing soluble S and having a high specific surface area.

Description

Technical Field

[0001] The present invention relates to a cathode active material suitable for use in electric vehicles (EVs) and hybrid electric vehicles (HEVs), the material comprising a soluble S content and having a high (specific) surface area, and constituting lithium transition metal oxide particles.

[0002] A cathode active material is defined as a material that is electrochemically active in a cathode. It should be understood that an active material is a material that can capture and release Li ions when exposed to a voltage change over a predetermined time.

[0003] Cathode active materials and methods for producing them are known. For example, Example 7 of International Publication No. 2011 / 071068 (A1) discloses washing with Al2(SO4)3, rinsing with water, and heating at 600°C. As shown in Table 1 of International Publication No. 2011 / 071068 (A1), the specific surface area of Example 7 of International Publication No. 2011 / 071068 (A1) is 0.45 m 2 / g.

[0004] However, there is still a need to provide further improved cathode active materials.

Summary of the Invention

Problems to be Solved by the Invention

[0005] Accordingly, an object of the present invention is to provide a cathode active material having one or more improved electrochemical characteristics, such as initial charge capacity (DQ1) and capacity fade rate (QF), in an electrochemical cell, for example, by an increase in the specific surface area weight measured by BET. In particular, an object of the present invention is to provide a cathode active material having an improved initial charge capacity (DQ1) of at least 212 mAh / g and a capacity fade rate (QF) of at most 20% / 100 cycles, preferably in an electrochemical cell.

Means for Solving the Problems

[0006] This object is a positive electrode active material suitable for an electrochemical cell, the positive electrode active material containing Li, M', and oxygen, where M' is Ni with a content x of 60.0 mol% to 95.0 mol% with respect to M', Co with a content y of 0 ≤ y ≤ 40.0 mol% with respect to M', Mn with a content z of 0 ≤ z ≤ 70.0 mol% with respect to M', an element other than Li, O, Ni, Co, Mn, S, B, Zr, and Al with a content a of 0 ≤ a ≤ 2.0 mol% with respect to M', and soluble S with a content b of 0.1 mol% to 0.8 mol% with respect to M', B with a content c of 0 ≤ c ≤ 2.0 mol% with respect to M', Zr with a content d of 0 ≤ d ≤ 2.0 mol% with respect to M', Al with a content e of 0 ≤ e ≤ 2.0 mol% with respect to M', and x, y, z, a, b, c, d, and e are measured by ICP, x + y + z + a + b + c + d + e is 100.0 mol%, the positive electrode active material has a (specific) surface area of 0.6 m 2 / g to 1.1 m 2 / g when determined by BET measurement, and can be achieved by providing the positive electrode active material.

[0007] The present invention relates to the following embodiments.

[0008] Embodiment 1 In a first aspect, the present invention is a positive electrode active material suitable for an electrochemical cell, the positive electrode active material containing Li, M', and oxygen, where M' is Ni with a content x of 60.0 mol% to 95.0 mol% with respect to M', Co with a content y of 0 ≤ y ≤ 40.0 mol% with respect to M', Mn with a content z of 0 ≤ z ≤ 70.0 mol% with respect to M', Elements other than Li, O, Ni, Co, Mn, S, B, Zr, and Al with a content a of 0 ≤ a ≤ 2.0 mol% with respect to M', and Soluble S with a content b of 0.1 mol% - 0.8 mol% with respect to M', B with a content c of 0 ≤ c ≤ 2.0 mol% with respect to M', Zr with a content d of 0 ≤ d ≤ 2.0 mol% with respect to M', Al with a content e of 0 ≤ e ≤ 2.0 mol% with respect to M', are included, x, y, z, a, b, c, d, and e are measured by ICP, x + y + z + a + b + c + d + e is 100.0 mol%, When determined by BET measurement, the positive electrode active material has a (specific) surface area of 0.6 m 2 / g to 1.1 m 2 / g. It relates to a positive electrode active material.

[0009] Preferably, the soluble S content b is b ≤ 0.7 mol% with respect to M', more preferably b ≤ 0.6 mol% with respect to M'.

[0010] Preferably, the soluble S content b is b ≥ 0.2 mol% with respect to M', more preferably b ≥ 0.3 mol% with respect to M'.

[0011] Preferably, the Ni content x is x ≥ 70.0 mol% with respect to M', more preferably x ≥ 80.0 mol% with respect to M', even more preferably x ≥ 81.0 mol% with respect to M'.

[0012] Preferably, the Ni content x is x ≤ 93.0 mol% with respect to M', more preferably x ≤ 91.0 mol% with respect to M'.

[0013] Preferably, the Co content y is y > 0 mol% with respect to M', more preferably y ≥ 1.0 mol% with respect to M', even more preferably y ≥ 5.0 mol% with respect to M'.

[0014] Preferably, the Co content y is y ≦ 30 mol% with respect to M', more preferably y ≦ 20.0 mol% with respect to M', and even more preferably y ≦ 10.0 mol% with respect to M'.

[0015] Preferably, the Mn content z is z > 0 mol% with respect to M', more preferably z ≧ 1.0 mol% with respect to M', and even more preferably z ≧ 5.0 mol% with respect to M'.

[0016] Preferably, the Mn content z is z ≦ 60 mol% with respect to M', more preferably z ≦ 50.0 mol% with respect to M', and even more preferably z ≦ 40.0 mol% with respect to M', and most preferably z ≦ 20.0 mol% with respect to M'.

[0017] In another embodiment, the Ni with the content x is 70 mol% to 91 mol% with respect to M', the Co with the content y is 0.0 mol% to 20.0 mol% with respect to M', and the Mn with the content z is 0.0 mol% to 20.0 mol% with respect to M'.

[0018] Preferably, the soluble S has a content b of 0.2 mol% to 0.7 mol% with respect to M', more preferably a content b of 0.3 mol% to 0.6 mol% with respect to M'.

[0019] The soluble sulfur content can be easily determined by ICP analysis after washing the positive electrode active material of the present invention with water. For example, the soluble sulfur can be determined according to Section A) ICP analysis of the form for carrying out the invention.

[0020] In the framework of the present invention, ppm means parts per million for the unit of concentration and represents 1 ppm = 0.0001 wt%.

[0021] Furthermore, in the framework of the present invention, the term "sulfur" refers to the presence of sulfur atoms or sulfur elements in the claimed positive electrode active material.

[0022] Embodiment 2 In the second embodiment, preferably according to Embodiment 1, the B content c is 0.01 mol% to 2.0 mol% with respect to M'.

[0023] Preferably, the B content c satisfies c ≤ 1.5 mol% with respect to M', and more preferably c ≤ 1.0 mol% with respect to M'.

[0024] Embodiment 3 In the third embodiment, preferably according to Embodiment 1 or Embodiment 2, the Zr content d is 0.01 mol% to 2.0 mol% with respect to M'.

[0025] Preferably, the Zr content d satisfies d ≤ 1.0 mol% with respect to M', and more preferably d ≤ 0.5 mol% with respect to M'.

[0026] Preferably, the Zr content d satisfies d ≥ 0.02 mol% with respect to M', and more preferably d ≥ 0.05 mol% with respect to M'.

[0027] Preferably, the Al content e is 0.01 mol% to 2.0 mol% with respect to M'.

[0028] Preferably, the Al content e satisfies e ≤ 1.0 mol% with respect to M', and more preferably e ≤ 0.5 mol% with respect to M'.

[0029] Preferably, the Al content e satisfies e ≥ 0.02 mol% with respect to M', and more preferably e ≥ 0.05 mol% with respect to M'.

[0030] Preferably, the element content a is 0.01 mol% to 2.0 mol% with respect to M'.

[0031] Preferably, the element content a satisfies a ≤ 1.0 mol% with respect to M', and more preferably a ≤ 0.5 mol% with respect to M'.

[0032] Preferably, the element content a satisfies a ≥ 0.02 mol% with respect to M', and more preferably a ≥ 0.05 mol% with respect to M'.

[0033] Preferably, elements other than Li, O, Ni, Co, Mn, S, B, Zr, and Al are selected from the group consisting of Ba, Ca, Cr, Fe, Mg, Mo, Nb, Si, Sr, Ti, Y, V, W, and Zn.

[0034] Embodiment 4 In the fourth embodiment, preferably according to Embodiment 1, when determined by BET measurement, the substance has a (specific) surface area of 0.65 m 2 / g to 1.10 m 2 / g.

[0035] Preferably, the substance has a (specific) surface area of at least 0.70 m 2 / g, more preferably at least 0.75 m 2 / g, even more preferably at least 0.80 m 2 / g.

[0036] Preferably, the substance has a (specific) surface area of at most 1.05 m 2 / g, more preferably at most 1.00 m 2 / g.

[0037] Embodiment 5 In the fifth embodiment, according to Embodiment 1 or Embodiment 2, when determined by laser diffraction particle size analysis, the substance has a secondary particle median diameter D50 of at least 2 μm, preferably at least 3 μm.

[0038] Preferably, when determined by laser diffraction particle size analysis, the substance has a secondary particle median diameter D50 of at most 15 μm, preferably at most 10 μm.

[0039] The present invention relates to the use of the positive electrode active material according to any one of Embodiments 1 to 5 described above in a battery.

[0040] The battery is a rechargeable lithium-ion battery including a cathode, an anode, a separator, and an electrolyte. Preferably, the electrolyte is a non-aqueous liquid electrolyte. The cathode active material of the present invention is used in the cathode.

[0041] The present invention also relates to the use of the battery according to the present invention in an electric vehicle or a hybrid electric vehicle.

[0042] Embodiment 6 In a second aspect, the present invention also provides a process for manufacturing a cathode active material, comprising: Step 1) mixing a lithium transition metal oxide powder with water to obtain a slurry, filtering the slurry, and then drying the slurry to obtain a dried powder; Step 2) mixing the dried powder with a solution containing an S-containing compound to obtain a mixture, wherein the solution contains S in an amount of 300 ppm to 3000 ppm based on the weight of the dried powder; Step 3) heating the mixture at a temperature of 250 °C to less than 500 °C in an oxidizing atmosphere to obtain a cathode active material.

[0043] Preferably, Step 1 is advantageously used to remove impurities such as lithium carbonate and obtain a cathode material with improved properties. This is because the presence of such lithium compounds may generate gas during, for example, high-temperature storage, which is undesirable.

[0044] Preferably, in Step 1), the solid content in the slurry is at most 80% by weight, more preferably at most 70% by weight.

[0045] Preferably, in step 1), the lithium transition metal oxide powder used is also typically prepared according to a lithiation process, i.e., a process of heating a mixture of a transition metal precursor and a lithium source at a temperature of at least 500 °C. Typically, the transition metal precursor is prepared by coprecipitation of one or more transition metal sources, such as salts of M' elements Ni, Mn, and / or Co, preferably sulfates, in the presence of an alkali compound, such as an alkali hydroxide, such as sodium hydroxide and / or ammonia.

[0046] In one embodiment of step 1), the lithium transition metal oxide powder contains Zr as a dopant. Such a lithium transition metal oxide powder can be obtained by adding a Zr-containing compound together with a lithium source to a transition metal oxide precursor in a lithiation process to prepare a lithium transition metal oxide. Alternatively, the Zr-containing compound may be mixed with the transition metal oxide precursor before the lithiation process.

[0047] Preferably, the Zr-containing compound contains zirconium oxide.

[0048] The advantage of adding Zr as a dopant is to improve the electrochemical properties of the positive electrode active material according to the present invention.

[0049] Optionally, an element-containing compound can also be added as a dopant to the positive electrode material in step 1). Preferably, the element-containing compound is added to the transition metal oxide precursor together with a lithium source in a lithiation process to prepare a lithium transition metal oxide. Alternatively, the element-containing compound may be mixed with the transition metal oxide precursor before the lithiation process.

[0050] Typically, the element of the element-containing compound is an element other than Li, O, Ni, Co, Mn, S, B, Zr, and Al. Preferably, the element is selected from the group consisting of Ba, Ca, Cr, Fe, Mg, Mo, Nb, Si, Sr, Ti, Y, V, W, and Zn.

[0051] The advantage of adding the element as a dopant is, for example, to improve the electrochemical properties of the cathode active material according to the present invention.

[0052] In step 2), preferably, the solution containing the S-containing compound contains S in an amount of 500 ppm to 2700 ppm, more preferably in an amount of 600 ppm to 2800 ppm, and most preferably in an amount of 800 ppm to 2500 ppm based on the weight of the dry powder.

[0053] Preferably, in step 2), the S-containing compound contains Al2(SO4)3.

[0054] In another embodiment of step 2), the S-containing compound used may contain sulfuric acid and / or sulfate in addition to or instead of Al2(SO4)3.

[0055] In step 3), preferably, the heating temperature is at least 250°C, more preferably at least 280°C, and most preferably at least 300°C.

[0056] In step 3), preferably, the heating temperature is at most 450°C, more preferably at most 420°C, and most preferably at most 400°C.

[0057] Preferably, in step 3), the heating time is 1 hour to 20 hours.

[0058] Embodiment 7 In the seventh embodiment, according to Embodiment 6, step 2) optionally includes adding a B-containing compound to the solution together with the S-containing compound. Preferably, the added B-containing compound is in powder form.

[0059] Preferably, in step 2), the solution further contains a B compound containing B in an amount of 100 ppm to 2000 ppm, more preferably in an amount of 200 ppm to 1800 ppm, and most preferably in an amount of 500 ppm to 1500 ppm.

[0060] Preferably, the B-containing compound added to the solution in step 1) may include, but is not limited to, boric acid, boron oxide, and / or lithium borate oxide.

[0061] Embodiment 8 In the eighth embodiment, according to Embodiments 6 to 7, the positive electrode active material obtained in step 3) is preferably the positive electrode active material of the present invention described in any one of the above Embodiments 1 to 5.

Mode for Carrying Out the Invention

[0062] In the following mode for carrying out the invention, preferred embodiments are described in order to enable the implementation of the present invention. Although the present invention is described with reference to these specific preferred embodiments, it will be understood that the present invention is not limited to these preferred embodiments. The present invention includes many alternatives, modifications, and equivalents that will be apparent from the consideration of the following mode for carrying out the invention.

[0063] A) ICP analysis A1) ICP measurement The amounts of Li, Ni, Mn, Co, S, B, and Zr in the positive electrode active material powder are measured by the inductively coupled plasma (ICP) method using an Agillent ICP720-ES (Agilent Technologies). A 2-gram powder sample is dissolved in 10 mL of high-purity hydrochloric acid (at least 37 wt% HCl with respect to the total weight of the solution) in an Erlenmeyer flask. The flask is covered with glass and heated on a hot plate at 380 °C until the precursor is completely dissolved. After cooling to room temperature, the solution in the Erlenmeyer flask is poured into a 250-mL volumetric flask. Then, the 250-mL volumetric flask is filled with deionized water up to the calibration mark, and subsequently, it is thoroughly homogenized. An appropriate amount of the solution is taken out with a pipette, transferred to a 250-mL volumetric flask for a second dilution, and after filling the 250-mL volumetric flask with an internal standard substance and 10% hydrochloric acid up to the calibration mark, it is homogenized. Finally, this 50-mL solution is used for ICP measurement. The amount of S obtained from this process is named total S, which includes both soluble S and insoluble S.

[0064] A2) Soluble sulfur measurement To examine the soluble S content in the lithium transition metal oxide particles according to the present invention, a washing and filtration process is carried out. 5 grams of the positive electrode active material powder and 100 grams of ultrapure water are weighed into a beaker. The electrode active material powder is dispersed in water at 25 °C for 5 minutes using a magnetic stirrer. The dispersion is vacuum filtered, and the dried powder is analyzed by the above ICP measurement to determine the amount of S remaining in the compound. The difference between the amount of S contained in the positive electrode material powder before washing and the amount of S contained in the positive electrode material powder before washing is defined as insoluble S (mol%) with respect to the molar content of Ni, Mn, and Co.

[0065] The amount of soluble sulfur is calculated according to Equation 1 below, Soluble S = S (total S) in the positive electrode material powder before washing - S (insoluble S) in the positive electrode material powder after washing (Equation 1) The amount (mol%) of total S is measured by ICP with respect to the total amount of Ni, Mn, and Co.

[0066] B) Particle size The particle size distribution (PSD) of the positive electrode active material powder is measured by laser diffraction particle size analysis using a Malvern Mastersizer 3000 equipped with a Hydro MV wet dispersion accessory after dispersing each powder sample in an aqueous medium. To improve the dispersion of the powder, sufficient ultrasonic irradiation and stirring are applied, and an appropriate surfactant is introduced. D50 is defined as the particle size at 50% of the cumulative volume % distribution obtained from the Malvern Mastersizer 3000 based on the Hydro MV measurement value.

[0067] C) Coin cell test C1) Preparation of coin cell In the preparation of the positive electrode, a slurry containing the positive electrode active material powder, a conductive agent (Super P, Timcal), and a binder (KF#9305, Kureha) in a weight ratio of 96.5:1.5:2.0 is prepared by a high-speed homogenizer in a solvent (NMP, Mitsubishi). The homogenized slurry is spread on one side of an aluminum foil using a doctor blade coater with a gap of 170 μm. The foil coated with the slurry is dried in an oven at 120 °C and then pressed using a calendaring tool. Then, it is dried again in a vacuum oven to completely remove the residual solvent in the electrode film. The coin cell is assembled in a glove box filled with argon. A separator (Celgard 2320) is placed between the positive electrode and a lithium foil piece used as the negative electrode. 1 M LiPF6 in EC / DMC (1:2) is used as the electrolyte and is dropped between the separator and the electrode. Then, the coin cell is completely sealed to prevent electrolyte leakage.

[0068] C2) Test method The test method is the conventional "constant cut-off voltage" test. The conventional coin cell test in the present invention follows the schedule shown in Table 2. Each cell is subjected to a cycle test at 25 °C using a Toscat-3100 computer-controlled galvanostatic cycling station (manufactured by Toyo).

[0069] The schedule used a 1C current definition of 220 mA / g in the range of 4.3 V to 3.0 V / Li metal window. The capacity fade rate (QF) is obtained by the following Equation 2. QF (% / 100 cycles) = 100 × (1 - DQ 34 / DQ7) × 1 / 27 × 100 Equation 2 In the formula, DQ1 is the discharge capacity of the first cycle, and DQ25 is the discharge capacity of the 25th cycle.

[0070]

Table 1

[0071] D) Specific surface area analysis The specific surface area (or surface area) of the positive electrode active material is measured by the Brunauer-Emmett-Teller (BET) method using a Micromeritics TristarII 3020. To remove the adsorbed species, the powder sample is heated at 300 °C for 1 hour under nitrogen (N2) gas before measurement. The dried powder is placed in a sample tube. Then, the sample is degassed at 30 °C for 10 minutes. In this apparatus, a nitrogen adsorption test is performed at 77 K. By obtaining the nitrogen isothermal adsorption / desorption curve, the total specific surface area of the sample is derived in units of m 2 / g.

[0072] The present invention will be further described by the following (non-limiting) examples.

[0073] Comparative Example 1 Comparative Example 1 (CEX1) is obtained by a solid-state reaction between a lithium source and a transition metal-based source, which is carried out as follows. 1) Coprecipitation: A transition metal-based oxyhydroxide precursor having a metal composition of Ni 0.83 Mn 0.05 Co 0.12 is prepared by a coprecipitation process in a large continuous stirred tank reactor (CSTR) containing mixed nickel-manganese-cobalt sulfate, sodium hydroxide, and ammonia. 2) First mixing: The transition metal-based oxyhydroxide precursor and 2000 ppm of Zr from ZrO2 are homogeneously mixed in an industrial blending apparatus to obtain a first mixture. 3) Second mixing: The first mixture from step 2) and LiOH as a lithium source are homogeneously mixed in an industrial blending apparatus at a lithium-to-metal M' (Li / M') ratio of 1.04 to obtain a second mixture. 4) Heating: The mixture from step 3) is heated at 765 °C for 12 hours in an oxygen atmosphere, followed by crushing, sorting, and sieving to obtain a heated product. 5) Washing: The heated product from step 4) is washed with water at 15 °C for 10 minutes at a powder-to-water ratio of 1:1. The powder is filtered, dried under vacuum at 140 °C, and then sieved. The product of this process is CEX1 having M' containing Ni, Mn, and Co in a Ni:Mn:Co ratio of 0.83:0.05:0.012, as obtained by ICP. CEX1 has a D50 of 10.2 μm.

[0074] Example 1.1 Example 1.1 (EX1.1) is obtained by the following steps. 1) Preparation of aluminum sulfate solution: 7.01 grams of Al2(SO4)3·16H2O powder is mixed with 30 grams of deionized water. 2) Mixing: 1 kg of Comparative Example 1 is mixed with the aluminum sulfate solution prepared in step 1) to obtain a wet mixture. 3) Heating: The mixture obtained from step 1) is heated at 385 °C for 8 hours in an oxygen atmosphere, followed by grinding and sieving to obtain EX1.1.

[0075] Example 1.2 Example 1.2 (EX1.2) is prepared in the same manner as EX1.1, except that 11.68 grams of Al2(SO4)3·16H2O is used.

[0076] Comparative Example 2 Comparative Example 2 (CEX2) is prepared according to CEX1, except that step 5) washing is not included. Further, 1 kg of the heated powder from step 4) is mixed with an aluminum sulfate solution prepared by dissolving 7.01 grams of Al2(SO4)3·16H2O powder in 30 grams of deionized water with respect to the weight of the heated powder. The mixture is reheated at 385 °C for 8 hours in an oxygen atmosphere, and then ground and sieved to obtain CEX2.

[0077] Example 2.1 Example 2.1 (EX2.1) is prepared in the same manner as EX1, except that the amount of Al2(SO4)3·16H2O powder is 5.84 grams, and an additional 2.86 grams of H3BO3 powder is added to the wet powder obtained from step 1). The mixture is heated at 300 °C for 8 hours in an oxygen atmosphere, and then ground and sieved to obtain EX1.1.

[0078] Example 2.2 Example 2.2 (EX2.2) is prepared in the same manner as EX2.1, except that the heating temperature is 385 °C.

[0079] [Table 2]

[0080] * With respect to the molar contents of Ni, Mn, Co, Al, B, soluble S, and Zr

[0081] Table 2 summarizes the compositions, (specific) surface areas, and corresponding electrochemical properties of the examples and comparative examples.

[0082] CEX1 is 1.2 m 2It is a washed substance according to Chinese Patent No. 111422916(A) having a surface area of / g. CEX1 exhibits a DQ1 lower than 212 mAh / g and a QF higher than 20% / 100 cycles. EX1.1 and EX1.2 having the characteristics of the positive electrode material according to the present invention result in a substance having an improved initial charge capacity (DQ1) of at least 212 mAh / g and a capacity fade rate (QF) of at most 20% / 100 cycles in an electrochemical cell. Furthermore, the addition of B in EX2.1 and EX2.2 results in a positive electrode material according to the present invention having more improved electrochemical characteristics compared to the positive electrode materials of EX1.1 and EX1.2.

[0083] In one embodiment, the (specific) surface area of the positive electrode active material according to the present invention decreases by increasing the temperature in step 3) of the method of the present invention.

[0084] The lower specific surface area of Example 7 of International Publication No. 2011 / 071068(A1) of 0.45 m2 / g is due to a higher final heating temperature compared to the present invention.

Claims

1. A cathode active material suitable for a rechargeable lithium-ion battery, wherein the cathode active material contains Li, M', and oxygen, and M' is Ni with a content x of 60.0 mol% to 95.0 mol% with respect to M', Co with a content y of 0 ≤ y ≤ 40.0 mol% with respect to M', Mn with a content z of 0 ≤ z ≤ 70.0 mol% with respect to M', an element other than Li, O, Ni, Co, Mn, S, B, Zr, and Al with a content a of 0 ≤ a ≤ 2.0 mol% with respect to M', and soluble S with a content b of 0.1 mol% to 0.8 mol% with respect to M', B with a content c of 0 ≤ c ≤ 2.0 mol% with respect to M', Zr with a content d of 0 ≤ d ≤ 2.0 mol% with respect to M', Al with a content e of 0 ≤ e ≤ 2.0 mol% with respect to M', and x, y, z, a, b, c, d, and e are measured by ICP, x + y + z + a + b + c + d + e is 100.0 mol%, When determined by BET measurement, the positive electrode active material has a surface area of 0.6 m ２ / g to 1.1 m ２ / g, and is a positive electrode active material.

2. The cathode active material according to claim 1, wherein the B content c is 0.01 mol% to 2.0 mol% with respect to M'.

3. The cathode active material according to claim 1, wherein the Zr content d is 0.01 mol% to 2.0 mol% with respect to M'.

4. The cathode active material according to claim 1, wherein the soluble S content b is b ≤ 0.7 mol% with respect to M' or b ≤ 0.6 mol% with respect to M'.

5. The surface area is at most 1.05 m ２ / g, or at most 1.00 m ２ / g when determined by BET. The positive electrode active material according to claim 1.

6. The surface area is at least 0.65 m ２ / g, or at least 0.7 m ２ / g, or at least 0.75 m ２ / g, or at least 0.8 m ２ / g, and the cathode active material according to claim 1.

7. The cathode active material according to claim 1, wherein the Al content e is 0.01 mol% to 2.0 mol% with respect to M'.

8. The cathode active material according to claim 1, wherein the Ni content x is x ≥ 70.0 mol% with respect to M' or x ≥ 75.0 mol% and x ≤ 91.0 mol% with respect to M'.

9. The cathode active material according to claim 1, wherein the Co content y is 0 mol% to 20 mol% with respect to M', or the Mn content z is 0 mol% to 20 mol% with respect to M'.

10. The cathode active material according to claim 1, wherein the median diameter D50 of the secondary particles is at least 2.0 μm and at most 15.0 μm when determined by laser diffraction particle size analysis.

11. A method for manufacturing the cathode active material according to any one of claims 1 to 10, wherein the method includes Step 1) mixing a lithium transition metal oxide powder with water to obtain a slurry, filtering the slurry, and then drying the slurry to obtain a dry powder. Step 2) mixing the dry powder with an aqueous solution containing Al ２ (SO ４ ) ３ to obtain a mixture, wherein the solution contains S in an amount of 300 ppm to 3000 ppm based on the weight of the dry powder, and obtaining a mixture Process 3) heating the mixture at a temperature of from 250°C to less than 500°C in an oxidizing atmosphere to obtain the positive electrode active material, and a continuous process thereof. A method.

12. The method according to claim 11, wherein in Process 3), the mixture is heated at a temperature of from 250°C to 450°C.

13. The method according to claim 11, wherein in Process 2), the B-containing compound is added to the solution in an amount of B of from 100 ppm to 2000 ppm based on the weight of the dry powder, or the B-containing compound is selected from boric acid, boron oxide, and / or lithium borate oxide.

14. A battery comprising the positive electrode active material according to any one of claims 1 to 10.

15. Use of the battery according to claim 14 in an electric vehicle or a hybrid electric vehicle.

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