The present invention discloses a preparation method for high density aluminum doped cobalt oxide, which comprises following steps: 1) adding a cobalt salt solution, an alkaline solution and an oxidizer to a reactor for reaction; adding an aluminum cobalt solution to the reaction system for reaction; stopping adding the aluminum cobalt solution after D50 reaches 3.5-4.0 μm, stopping the reaction when D50 reaches the desired particle size, thus obtaining aluminiferous cobalt oxyhydroxide slurry; 2) aging, dehydrating, washing and drying the aluminiferous cobalt oxyhydroxide slurry, thus obtaining aluminiferous cobalt oxyhydroxide powder; 3) calcining the aluminiferous cobalt oxyhydroxide powder, thus obtaining the target object. With the method of the present invention, doped aluminum can be perfectly embedded into cobalt oxide lattices, thus effectively enhancing the tap density and uniformity of aluminum doped cobalt oxide and improving the cycle performance and charge-discharge performance of batteries.

The present invention discloses a preparation method for 2-4 μm battery-grade cobalt tetroxide, comprises following steps: 1) adding a cobalt salt solution and an alkaline solution by parallel flows to a reactor with a base solution and an air flow, controlling pH value of a system by adjusting flow rate of the alkaline solution for coprecipitation reaction at a certain stirring rate, decreasing the pH value of the reaction system and increasing flow rate of the cobalt salt solution after the reaction solutions begin to overflow; 2) aging and drying the cobalt oxyhydroxide slurry in sequence; 3) calcining the dried cobalt oxyhydroxide. By adopting this method, tap density of the battery-grade cobalt tetroxide obtained is much higher than that of cobalt tetroxide with a same particle size specification prepared by the prior art.

The present invention relates to entangled-type carbon nanotubes which have a bulk density of 31 kg/m.sup.3 to 85 kg/m.sup.3 and a ratio of tapped bulk density to bulk density of 1.37 to 2.05, and a method for preparing the entangled-type carbon nanotubes.

Process for making a mixed oxide according to the formula Li.sub.1+xTM.sub.1−xO.sub.2 wherein x is in the range of from 0.1 to 0.2 and TM is a combination of elements according to general formula (I) (Ni.sub.aCo.sub.bMn.sub.c).sub.1-dM.sup.1.sub.d (I) wherein a is in the range of from 0.30 to 0.38, b being in the range of from zero to 0.05, c being in the range of from 0.60 to 0.70, and d being in the range of from zero to 0.05, M.sup.1 is selected from Al, Ti, Zr, W, Mo, Nb, Ta, Mg and combinations of at least two of the forego-ing, a+b+c=1, said process comprising the following steps: (a) providing a particulate hydroxide, oxide or oxyhydroxide of manganese, nickel, and, optionally, at least one of Co and M.sup.1, (b) adding a source of lithium, (c) calcining the mixture obtained from step (b) thermally under an atmosphere comprising 0.05 to 5 vol.-% of oxygen at a maximum temperature the range of from 650 to 1000° C.

The present disclosure relates to a dissimilar metal-doped cerium oxide including cerium oxide and a dissimilar metal other than the cerium oxide, in which a relationship of the following formula (1) is satisfied:

0.8≤|(D90)−(D10)|/D50≤2.0  (1) (in the formula (1), D10, D50, and D90 respectively represent the following: D10: particle diameter at which cumulative volume fraction is 10% D50: particle diameter at which cumulative volume fraction is 50% D90: particle diameter at which cumulative volume fraction is 90%).

Lithium-ion battery (LIB) recycling is considered as an important component to industry sustainability. A massive number of LIBs in portable electronics, electric vehicles and grid storage will eventually end up in wastes, leading to serious economic and environmental problems. Hence, tremendous effort has been made to improve hydrometallurgical recycling process since it is the most promising option for handling end-of-life LIBs owing to its wide applicability, low cost and high productivity. Despite these advantages, some extra elements (Al, Fe, C, F, etc.) remain as impurities in the removal process and remain in the solution, presenting a challenge to obtaining high-quality cathode material. This approach demonstrates the improved electrochemical performance by adding potential impurities in the leaching solution.

Provided is a method for producing a lithium transition metal oxide, comprising, A) mixing a lithium salt and a precursor, adding the mixture into a reactor for precalcination; the lithium salt has a particle size D50 of 10-20 μm and the precursor has a particle size D50 of 1-20 μm, and the precursor is one or more selected from transition metal oxyhydroxide, transition metal hydroxide and transition metal carbonate; and B) adding the product obtained from the precalcination into a fluidized bed reactor, subjecting to a first calcination and a second calcination to obtain the lithium transition metal oxide. Raw materials for the lithium transition metal oxide further includes a main-group metal compound containing oxygen, which is added in the precalcination, the first calcination or the second calcination; and the main-group metal compound containing oxygen has an average particle size of 10-100 nm. A fluidized bed reactor is also provided.

An LFP electrode material is provided which has improved impedance, power during cold cranking, rate capacity retention, charge transfer resistance over the current LFP based cathode materials. The electrode material comprises crystalline primary particles and secondary particles, where the primary particle is formed from a plate-shaped single-phase spheniscidite precursor and a lithium source. The LFP includes an LFP phase behavior where the LFP phase behavior includes an extended solid-solution range.

A method for producing a metal composite hydroxide, which includes a first crystallization process of obtaining first metal composite hydroxide particles by supplying a first raw material aqueous solution containing a metal element and an ammonium ion donor to a reaction tank, adjusting a pH of a reaction aqueous solution in the reaction tank, and performing a crystallization reaction and a second crystallization process of forming a tungsten-concentrated layer on a surface of the first metal composite hydroxide particles and obtaining second metal composite hydroxide particles by supplying a second raw material aqueous solution containing a metal element and a more amount of tungsten than the first raw material aqueous solution and an ammonium ion donor to a reaction aqueous solution containing the first metal composite hydroxide particles, adjusting a pH of the reaction aqueous solution, and performing a crystallization reaction, and the like.

The present application discloses a positive electrode active material including a lithium nickel cobalt manganese oxide, the molar content of nickel in the lithium nickel cobalt manganese oxide accounts for 60%-90% of the total molar content of nickel, cobalt and manganese, and the lithium nickel cobalt manganese oxide has a layered crystal structure of a space group R 3m; a transition metal layer of the lithium nickel cobalt manganese oxide includes a doping element, and the local mass concentration of the doping element in particles of the positive electrode active material has a relative deviation of 20% or less; and in a differential scanning calorimetry spectrum of the positive electrode active material in a 78% delithiation state, an initial exothermic temperature of a main exothermic peak is 200° C. or more, and an integral area of the main exothermic peak is 100 J/g or less.