Abstract: A battery pack includes a battery pack box with an internal space including a first region to an n-th region, each provided with a battery cell. A positive electrode active substance in a positive electrode of each k-th battery cell includes lithium iron phosphate and/or lithium nickel cobalt manganate having a first discharge voltage plateau and one or more types of supplementary active substances having a second discharge voltage plateau. For the first battery cell to the n-th battery cell, in any case where a sum of a discharge capacity corresponding to the first discharge voltage plateau and a discharge capacity corresponding to the second discharge voltage plateau is 100%, a discharge capacity proportion corresponding to the second discharge voltage plateau of the k-th battery cell is greater than a discharge capacity proportion corresponding to the second discharge voltage plateau of the (k?1)-th battery cell.

Abstract: A 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, and a discharging cut-off voltage of the battery pack at a low temperature has the following rules: discharging cut-off voltages V1, V2, and V3 of the first battery cell, second battery cell, and third battery cell range from 1.95V to 2.1V, from 1.8 V to 2.0V, from 1.6V to 1.9V, respectively, and V1, V2, and V3 satisfy a relationship of V1>V2>V3.

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: A positive active material made of carbon-coated lithium iron phosphate includes a lithium iron phosphate substrate, and a carbon coating layer on a surface of the substrate. The lithium iron phosphate substrate has a general structural formula LiFe1-aMaPO4, where M is at least one selected from Cu, Mn, Cr, Zn, Pb, Ca, Co, Ni, Sr, Nb, or Ti, and 0?a?0.01. A carbon coating factor of the carbon-coated lithium iron phosphate, ? = BET ? 1 BET ? 2 , satisfies 0.81???0.95, where BET1 denotes a specific surface area of mesopore and macropore structures in the carbon-coated lithium iron phosphate, and BET2 denotes a total specific surface area of the carbon-coated lithium iron phosphate.

Abstract: A battery pack may comprise a first battery cell type and a second battery cell type, wherein the first battery cell type may include n first battery cells, and the second battery cell type may include m second battery cells, with n and m being each independently selected from an integer of 1 or more. The second battery cell may have an internal resistance less than that of the first battery cell, the difference in internal resistance between the first battery cell and the second battery cell may be ?0.15 mohm; the percentage by number of the first battery cells in the battery cells comprised in the area A may be 20% to 100%; and the percentage by number of the second battery cells in the battery cells comprised in the area B may be 5% to 100%.

Abstract: A positive electrode composite material for a lithium-ion secondary battery is provided. In some embodiments, the positive electrode composite material for a lithium-ion secondary battery comprises: a positive electrode active material selected from at least one of a lithium iron phosphate material and a nickel cobalt lithium manganate material; and at least one of compounds represented by AaMb(PO4)cXd, wherein A is selected from at least one of Li, Na, K, and Ca, M is selected from at least one of V and Mn, X is selected from any one of halogen elements, a, b, and c are each independently selected from an integer from 1 to 6, and d is selected from an integer from 0 to 3.

Abstract: A positive electrode plate may include a current collector, a first positive electrode active material layer and a second positive electrode active material layer. The first positive electrode active material layer may comprise a first positive electrode active material, a first binder and a first conductive agent; the second positive electrode active material layer may comprise a second positive electrode active material, a second binder and a second conductive agent. The second positive electrode active material may be selected from carbon-coated Li?Fe?M(1??)PO4, and the second positive electrode active material may have a diffraction peak A between 29° and 30° in the X-ray diffraction pattern, and a diffraction peak B between 25° and 26°, and the intensity ratio IA/IB of the diffraction peaks may satisfy: 0.98?IA/IB?1.1.

Abstract: A positive-electrode material, a positive electrode plate, a lithium secondary battery, a battery module, a battery pack, and an apparatus are provided. The positive-electrode material in some embodiments includes lithium iron phosphate monocrystalline particles and lithium iron phosphate secondary particles. The lithium iron phosphate secondary particles have low specific surface area and can reduce binder and solvent consumption during slurry preparation, increase a solid content of slurry, and improve processing performance of a thick-coating plate. In addition, lithium iron phosphate monocrystal fully fills in gaps between the lithium iron phosphate secondary particles to further improve a compacted density of the plate and reduce a membrane resistance of the positive electrode plate, thereby improving performance of capacity per gram and cycling performance of the lithium secondary battery.

Abstract: A positive active material made of carbon-coated lithium iron phosphate includes a lithium iron phosphate substrate, and a carbon coating layer on a surface of the substrate. The lithium iron phosphate substrate has a general structural formula LiFe1-aMaPO4, where M is at least one selected from Cu, Mn, Cr, Zn, Pb, Ca, Co, Ni, Sr, Nb, or Ti, and 0?a?0.01. A carbon coating factor of the carbon-coated lithium iron phosphate, ? = BET ? 1 BET ? 2 , satisfies 0.81???0.95, where BET1 denotes a specific surface area of mesopore and macropore structures in the carbon-coated lithium iron phosphate, and BET2 denotes a total specific surface area of the carbon-coated lithium iron phosphate.

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: This application provides a mixed positive electrode material, a positive electrode plate and a preparation method thereof, a battery, and an apparatus. The mixed positive electrode material includes a mixed component consisting of a material of lithium iron phosphate chemical system and a material of ternary chemical system, where the material of lithium iron phosphate chemical system is secondary particles with an average specific surface area within 10 m2/g. In the mixed positive electrode material of this application, the introduction of lithium iron phosphate secondary particles having a low specific surface area improves ease of processing of the mixed positive electrode material, making a slurry less prone to agglomeration and the two materials highly miscible. When the positive electrode plate is prepared by using the mixed positive electrode material of this application, uniform distribution of the positive electrode material on the positive electrode plate can be effectively improved.