A positive electrode material, a positive electrode plate, a battery cell, a battery, and an electric apparatus are described. The positive electrode material includes a layered lithium-containing metal oxide, and the layered lithium-containing metal oxide is represented by a general formula Li.sub.aL.sub.xNi.sub.bCo.sub.cMn.sub.dM.sub.(1bcd)O.sub.eN.sub.f, where an L ion is a cation having a radius larger than a radius of a Li ion, M includes at least one of Mg, Zr, Al, B, Ta, Mo, W, Nb, Sb, and La, and N includes at least one of F, S, and P, where 0<a<2, 0b<1, 0c<1, 0d<1, 0<b+c+d1, 0<e2, 0f<2, and 0<x0.8. The technical solutions provided in the embodiments of this application help to improve performance of the positive electrode material and performance of the battery cell.

The present disclosure relates to the field of lithium-ion batteries and discloses a cathode material, a preparation method therefor, and a lithium-ion battery. The cathode material has a composition represented by Li.sub.1+a(Ni.sub.xCo.sub.yMn.sub.zGb)T.sub.cO.sub.2, where 0.02a0.1, 0.6x1, 0<y0.5, 0<z0.5, 0<b0.02, 0<c0.02. A characteristic peak (003) before and after 80 cycles at 45 C. satisfies 0P=P.sub.preP.sub.post0.2. This cathode material has a high particle strength and more excellent crystal structure stability, which makes cycling performance of the cathode material significantly improved.

The present disclosure relates to the field of lithium-ion batteries and discloses a cathode material, a preparation method therefor, and a lithium-ion battery. The cathode material has a composition represented by Li.sub.1+a(Ni.sub.xCo.sub.yMn.sub.zGb)T.sub.cO.sub.2, where 0.02a0.1, 0.6x1, 0<y0.5, 0<z0.5, 0<b0.02, 0<c0.02. A characteristic peak (003) before and after 80 cycles at 45 C. satisfies 0P=P.sub.preP.sub.post0.2. This cathode material has a high particle strength and more excellent crystal structure stability, which makes cycling performance of the cathode material significantly improved.

A positive electrode active material comprises a first active material having an average particle size (D50) from 2 to 10 m, and a second active material having an average particle size (D50) from 12 to 20 m. The first active material includes first particles that are a lithium-(transition metal) composite oxide, the first particles are at least one of single particles and secondary particles, and the secondary particles each consist of 2 to 10 primary particles aggregated together. The second active material includes second particles that are a lithium-(transition metal) composite oxide, and the second particles are secondary particles each consisting of 50 or more primary particles aggregated together. The second active material has a sphere degree from 0.770 to 0.810.

A positive electrode active material comprises a first active material having an average particle size (D50) from 2 to 10 m, and a second active material having an average particle size (D50) from 12 to 20 m. The first active material includes first particles that are a lithium-(transition metal) composite oxide, the first particles are at least one of single particles and secondary particles, and the secondary particles each consist of 2 to 10 primary particles aggregated together. The second active material includes second particles that are a lithium-(transition metal) composite oxide, and the second particles are secondary particles each consisting of 50 or more primary particles aggregated together. The second active material has a sphere degree from 0.770 to 0.810.

The present invention includes a positive electrode active material for a secondary battery, comprising a composite metal hydroxide precursor represented by Chemical Formula (1) below: wherein the precursor includes a secondary particle composed of a plurality of primary particles; wherein each primary particle is formed as a bundle of micro primary particles; wherein, when observed via a transmission electron microscope, the major axis direction of the micro primary particles coincides with the major axis direction of the primary particles; and wherein each micro primary particle has a thickness of about 1 nm to about 50 nm.

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A positive electrode active material comprises a secondary particle. The secondary particle includes crystallites. The crystallites extend radially from a center of the secondary particle toward outside. Each of the crystallites includes a lithium-metal composite oxide. The lithium-metal composite oxide has a lamellar-rock-salt-type structure. In a surface of the secondary particle, an open pore is formed between the crystallites that are adjacent to each other. The open pore has a pore diameter of 20 nm or more.

A positive electrode active material comprises a secondary particle. The secondary particle includes crystallites. The crystallites extend radially from a center of the secondary particle toward outside. Each of the crystallites includes a lithium-metal composite oxide. The lithium-metal composite oxide has a lamellar-rock-salt-type structure. In a surface of the secondary particle, an open pore is formed between the crystallites that are adjacent to each other. The open pore has a pore diameter of 20 nm or more.

A positive electrode active material and a preparation method therefor, a positive electrode sheet, a secondary battery, and an electric device, wherein the positive electrode active material comprises hollow secondary particles, the hollow secondary particles comprising Li.sub.aNi.sub.xCo.sub.yMn.sub.zA.sub.qM.sub.pO.sub.b, 0.25a1.2, 1.8b2, 0.3x0.6, 0y0.4, 0<z0.4, 0q0.02, and 0<p0.02, the atomic percentage of element M at grain boundaries being greater than or equal to the atomic percentage of element M in bulk phase parts of primary particles, and element A being distributed in the hollow secondary particles in the form of bulk phase doping. The positive electrode active material comprises the hollow secondary particles, element M is mainly distributed at the grain boundary of the hollow secondary particles, and element A can be optionally doped, thereby keeping good cycle performance while effectively improving the power performance.

A positive electrode active material and a preparation method therefor, a positive electrode sheet, a secondary battery, and an electric device, wherein the positive electrode active material comprises hollow secondary particles, the hollow secondary particles comprising Li.sub.aNi.sub.xCo.sub.yMn.sub.zA.sub.qM.sub.pO.sub.b, 0.25a1.2, 1.8b2, 0.3x0.6, 0y0.4, 0<z0.4, 0q0.02, and 0<p0.02, the atomic percentage of element M at grain boundaries being greater than or equal to the atomic percentage of element M in bulk phase parts of primary particles, and element A being distributed in the hollow secondary particles in the form of bulk phase doping. The positive electrode active material comprises the hollow secondary particles, element M is mainly distributed at the grain boundary of the hollow secondary particles, and element A can be optionally doped, thereby keeping good cycle performance while effectively improving the power performance.