Abstract: 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 LiaNixCoyMnzAqMpOb, 0.25?a?1.2, 1.8?b?2, 0.3?x?0.6, 0?y?0.4, 0<z?0.4, 0?q?0.02, and 0<p?0.02, 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.

Abstract: A positive electrode active material, a positive electrode plate, a secondary battery, and a power consuming apparatus are provided. The positive electrode active material includes (i) secondary particles and (ii) single-crystal or quasi-single-crystal particles. The secondary particles are mainly formed by aggregating primary particles and the secondary particles further include an M1 element. The M1 element includes a transition metal element other than iron. A mass content of the M1 element is X1 based on a total mass of the secondary particles, where 500 ppm?X1?5000 ppm, and optionally, 800 ppm?X1?2000 ppm. The single-crystal or quasi-single-crystal particles include an Ma element. The Ma element includes a transition metal element other than iron. A mass content of the Ma element is X2 based on a total mass of the single-crystal or quasi-single-crystal particles, where X2 is less than X1.

Abstract: A single-crystalline-structured low-cobalt ternary positive material, a chemical formula thereof is Li1+x(NiaCObMnc)1-dMdO2-yAy, where a mole fraction of Co element is low, 0.05?b?0.14; and in a single particle, a ratio of an average Co content per unit area of an outer layer to an average Co content per unit area of an inner core in a cross section passing through a geometric center of the particle is in a range 1.2-5.0:1, optionally, in a range 1.4-2.0:1 is disclosed. The material has better structural stability and dynamic performance at low temperature and high voltage, which improves cycle performance and power performance of the secondary battery at low temperature and high voltage.

Abstract: Provided are a positive electrode active material and a preparation method therefor, a battery cell, and an electric device. The positive electrode active material includes a lithium-containing phosphate, where an X-ray diffraction pattern of the positive electrode active material tested in a fully charged state satisfies: there is a (311) crystal plane peak in a range of 35° to 36° and a (011) crystal plane peak in a range of 20° to 21°, and the ratio of a peak intensity I311 of the (311) crystal plane peak to a peak intensity I011 of the (011) crystal plane peak satisfies I311/I011?0.008. The positive active material can improve the cycle performance of a battery.

Abstract: A positive electrode plate, a preparation method thereof, a secondary battery, and an electric apparatus. The positive electrode plate includes a current collector and a positive electrode film layer formed on at least one side of the current collector. The positive electrode film layer includes a positive electrode active material comprising a substrate and a carbon coating layer on the surface of the substrate. The substrate has a general formula LizFexMn(1-x-y)MyPO4, where 1?z?1.1, 0.5?x?1, 0?y?0.1, and M is at least one of Ti, V, and Mg. At least part of the active material includes primary particles, with no more than 10% having sizes between 80 nm and 180 nm, and no more than 15 particles exceeding 1500 nm within a defined microscopic region. This structure improves the particle size distribution concentration, enhancing the cycling performance of batteries.

Abstract: The present application discloses a positive electrode active material, a preparation method thereof, a battery cell, and a power consuming apparatus. The positive electrode active material includes a lithium-containing phosphate, a charge capacity per gram of the positive electrode active material at 25° C. is denoted as C1, the charge capacity per gram of the positive electrode active material at 60° C. is denoted as C2, both units are mAh/g, and C2/C1?1.020. The positive electrode active material provided in the present application can improve a cycle performance of a battery.

Abstract: A positive electrode active material, a positive electrode plate, a secondary battery, and a power consuming apparatus are provided. The positive electrode active material includes (i) secondary particles and (ii) single-crystal or quasi-single-crystal particles. The secondary particles are mainly formed by aggregating primary particles and the secondary particles further include an M1 element. The M1 element includes a transition metal element other than iron. A mass content of the M1 element is X1 based on a total mass of the secondary particles, where 500 ppm?X1?5000 ppm, and optionally, 800 ppm?X1?2000 ppm. The single-crystal or quasi-single-crystal particles include an Ma element. The Ma element includes a transition metal element other than iron. A mass content of the Ma element is X2 based on a total mass of the single-crystal or quasi-single-crystal particles, where X2 is less than X1.

Abstract: 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 LiaNixCoyMnzAqMpOb, 0.25?a?1.2, 1.8?b?2, 0.3?x?0.6, 0?y?0.4, 0<z?0.4, 0?q?0.02, and 0<p?0.02, 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.

Abstract: The positive electrode sheet comprises a positive electrode film layer located on at least one side of a current collector The particle size distribution index of an active material in the first area of the positive electrode film layer is smaller than the particle size distribution index of an active material in the second area of the positive electrode film layer The particle size distribution index is the ratio of the standard deviation of the particle size of an active material to the average particle size thereof, the first area is an area where the positive electrode film layer extends vertically from the surface on the side close to the current collector to the positive electrode film layer within a distance h1, the second area is an area where the positive electrode film layer extends vertically from the surface on the side close to the current collector.

Abstract: A single-crystalline-structured low-cobalt ternary positive material, a chemical formula thereof is Li1+x(NiaCObMnc)1?dMdO2?yAy, where a mole fraction of Co element is low, 0.05?b?0.14; and in a single particle, a ratio of an average Co content per unit area of an outer layer to an average Co content per unit area of an inner core in a cross section passing through a geometric center of the particle is in a range 1.2-5.0:1, optionally, in a range 1.4-2.0:1 is disclosed. The material has better structural stability and dynamic performance at low temperature and high voltage, which improves cycle performance and power performance of the secondary battery at low temperature and high voltage. A method for preparing the low-cobalt ternary positive material, a secondary battery, a battery module, a battery pack, and a power consumption apparatus including the material is also disclosed.

Abstract: The present application provides a positive electrode plate and a preparation method therefor, as well as a secondary battery, and an electrical apparatus. The positive electrode plate of the present application has a higher compacted density.

Abstract: This application provides a composite positive electrode material and preparation method thereof, a positive electrode plate, a secondary battery, and an electric apparatus. The preparation method includes: mixing a lithium source, a phosphorus source, an iron source, a carbon source, and a carbon graphitization catalyst in a predetermined ratio with a solvent to form a mixed slurry; grinding and drying the mixed slurry to obtain a mixed dry substance; and sintering the mixed dry substance to obtain the composite positive electrode material, a sintering temperature being 750° C.-840° C.

Abstract: A positive electrode plate includes a positive current collector and a positive electrode film layer. The positive electrode film layer is disposed on at least one surface of the positive current collector. The positive electrode film layer includes a first positive electrode film layer and a second positive electrode film layer. The first positive electrode film layer is located between the positive current collector and the second positive electrode film layer. The first positive electrode film layer includes a first positive active material. A specific surface area of the first positive active material is 12 m2/g to 16 m2/g. The second positive electrode film layer includes a second positive active material. A specific surface area of the second positive active material is 6 m2/g to 19 m2/g.

Abstract: A method for preparing lithium iron phosphate includes: mixing iron phosphate, a lithium source, a carbon source, a dispersant, and a solvent to make a precursor slurry; sintering the precursor slurry to make lithium iron phosphate, where the dispersant includes an ammonium salt compound represented by Formula (1), in which R1 is a carbon-containing organic group.

Abstract: A composite positive electrode material and a preparation method thereof, a positive electrode plate, a battery, and an electrical device. The composite positive electrode material includes a composite formed by a positive active material and carbon. In a particle structure of the composite, a mass ratio of a carbon content inside to a carbon content on a surface is (0.8 to 2):1.

Abstract: A positive active material is provided. In some embodiments, the positive material includes: a substrate and a coating layer coating the substrate, wherein the coating layer includes a fast ion conductor layer and a carbon coating layer, the substrate includes more than one compound of formula (I): LiFe1-aM1aPO4 formula (I), in formula (I), M1 is more than one selected from Cu, Mn, Cr, Zn, Pb, Ca, Co, Ni, Sr, Nb and Ti, and 0?a?0.01; the fast ion conductor layer includes a fast ion conductor of a NASICON structure shown in formula (II), Li3-bFe2-bM2b(PO4)3 formula (II), in formula (II), M2 is more than one selected from Ti, Zr, Hf, Ge and Sn with valence of +4, and 0?b?1.

Abstract: Provided is a battery pack. The battery pack includes a first battery cell, a second battery cell, and a third battery cell. A positive electrode active substance of each battery cell is composed of lithium iron phosphate and a low-temperature additive. The low-temperature additive is selected from compounds containing at least two carbonyl groups, which are conjugated with an unsaturated structure or an atom having lone-pair electrons connected with the carbonyl groups. At a temperature lower than or equal to 10° C., a ratio of a discharging capacity of a single cell of the second battery cell to a discharging capacity of a single cell of the first battery cell ranges from 1.003 to 1.12, and a ratio of a discharging capacity of a single cell of the third battery cell to a discharging capacity of a single cell of the second battery cell ranges from 1.005 to 1.15.

Abstract: A positive active material is provided. In some embodiments, the positive material includes: a substrate and a coating layer coating the substrate, wherein the coating layer includes a fast ion conductor layer and a carbon coating layer, the substrate includes more than one compound of formula (I): LiFe1-aM1aPO4 formula (I), in formula (I), M1 is more than one selected from Cu, Mn, Cr, Zn, Pb, Ca, Co, Ni, Sr, Nb and Ti, and 0?a?0.01; the fast ion conductor layer includes a fast ion conductor of a NASICON structure shown in formula (II), Li3-bFe2-bM2b(PO4)3 formula (II), in formula (II), M2 is more than one selected from Ti, Zr, Hf, Ge and Sn with valence of +4, and 0?b?1.

Abstract: A secondary battery is described. The secondary battery includes a positive electrode plate, a negative electrode plate, and an electrolyte solution. The positive electrode plate includes a positive current collector and a positive electrode film layer disposed on at least one surface of the positive current collector. The positive electrode film layer includes a positive active material. The positive active material includes: S1) a lithium-containing compound of an olivine structure, and S2) a vanadium oxide represented by a general formula j(M2O) ·kVOx, where M is one or more of alkali metals, 0?j?1, 1?k?5, 1?x?2.5, a difference of a discharge platform voltage between S1 and S2 is E, and 0.2 V?E?2.8 V.

Abstract: The present application provides a secondary battery, a battery module, a battery pack, and an electrical device. The secondary battery includes a positive electrode plate, a negative electrode plate, and a separator disposed between the positive electrode plate and the negative electrode plate, in which the positive electrode plate comprises a positive electrode coating containing a positive electrode active material comprising a lithium iron phosphate material and a conjugated carbonyl compound. In a discharge process of the secondary battery, in addition to a discharge plateau of the lithium iron phosphate material, a discharge curve further includes a relatively low discharge plateau provided by the conjugated carbonyl compound.