CN-117566811-B - Ultra-high nickel positive electrode material precursor, preparation method thereof, positive electrode material and battery

CN117566811BCN 117566811 BCN117566811 BCN 117566811BCN-117566811-B

Abstract

The application discloses an ultra-high nickel anode material precursor, a preparation method thereof, an anode material and a battery, and belongs to the technical field of batteries. The preparation method of the ultra-high nickel anode material precursor comprises the following steps of adding a mixed metal sulfate solution, a sodium meta-gallate solution, a complexing agent and a precipitant into a base solution for coprecipitation reaction until the particle size of particles obtained by the reaction reaches a preset value, wherein the complexing agent is oxalic acid solution, and the precipitant is sodium hydroxide solution. According to the preparation method, gallium is co-precipitated with other raw materials in a reaction system in a sodium meta-gallate solution mode, doping of gallium can be achieved in a reaction stage of preparing the precursor, first precipitation of Ga 3+ can be avoided, molecular-level mixing of metal elements is achieved, and therefore a hydroxide precursor with relatively uniform element distribution is obtained, stability of a layered structure of a nickel precursor material is improved, interlayer spacing of the material is enlarged, and circulation stability of the material is improved.

Inventors

ZHANG BIN
LI GUANFENG
XING WANGYAN
YANG RUI
LI RAN
CHEN JING
WANG CHENGQIAO
ZUO MEIHUA
WANG ZHENGQIANG

Assignees

宜宾光原锂电材料有限公司
宜宾锂宝新材料有限公司

Dates

Publication Date: 20260505
Application Date: 20231122

Claims (8)

1. The preparation method of the ultra-high nickel anode material precursor is characterized by comprising the following steps of adding a mixed metal sulfate solution, a sodium meta-gallate solution, a complexing agent and a precipitant into a base solution for coprecipitation reaction until the particle size of particles obtained by the reaction reaches a preset value; the mixed metal sulfate solution comprises a nickel-containing sulfate solution, a cobalt-containing sulfate solution and a manganese-containing sulfate solution, and the preparation of the sodium meta-gallate solution comprises the steps of mixing water, sodium hydroxide and gallium sulfate, wherein the complexing agent is an oxalic acid solution, and the precipitant is a sodium hydroxide solution; The coprecipitation reaction is carried out by adding mixed metal sulfate solution, sodium meta-gallate solution, complexing agent and precipitant into base solution under stirring, reacting at 50-65deg.C, feeding mixed metal sulfate solution with flow rate >0 and less than or equal to 2L/h, mixing mixed metal sulfate solution with nickel-containing sulfate solution, cobalt-containing sulfate solution and manganese-containing sulfate solution, mixing mixed metal sulfate solution with total concentration 1.5-3 mol/h, complexing agent with oxalic acid solution with concentration 0.25-1.5mol/L, complexing agent with oxalic acid radical concentration 0.5mol/L into reaction system in reaction container, adding precipitant with sodium hydroxide solution, feeding precipitant to control pH value of reaction system in reaction container to 11.6-12.0, adding sodium meta-gallate solution with concentration 0.1-0.5mol/L, flow rate >0 and 0.3L/h, reacting for 4h, reducing pH value of reaction system to 11.11.0-11 at speed of 0.05-0.1 mol/L per hour.
2. The method according to claim 1, wherein the concentration of sodium hydroxide in the precipitant is 20-40wt%.
3. The method of claim 1, wherein the base fluid comprises at least one of the following characteristics: the method is characterized in that the base solution comprises water, a complexing agent and a precipitant; the volume of water in the base solution is 40-60% of the volume of the reaction container; the complexing agent in the base solution is oxalic acid solution, and the concentration of the oxalic acid solution is 0.25-1.5mol/L; the fourth characteristic is that the precipitant in the base solution is sodium hydroxide solution; and fifthly, the pH value of the base solution is 11.6-12.0.
4. The method according to claim 1, wherein the coprecipitation reaction is carried out under a protective gas atmosphere.
5. The method of claim 1, further comprising post-treatment after the coprecipitation reaction; The post-treatment comprises the steps of carrying out solid-liquid separation, centrifugal washing, demagnetizing, drying, screening and mixing treatment on slurry obtained by the coprecipitation reaction; The post-processing includes at least one of the following features: The first characteristic is that the centrifugal washing comprises alkali washing with 1-3mol/L sodium hydroxide for 10-30min to remove excessive sulfate ion, washing with 70-100deg.C hot water for 20-60min to remove excessive sodium ion; Secondly, when Na is less than or equal to 100ppm and S is less than or equal to 1000ppm in the solid sample after centrifugal washing, carrying out demagnetizing treatment on the sample; The third feature is that when the magnetic foreign matter in the sample after the demagnetization is less than or equal to 100 mug/kg, the sample is dried at 80-120 ℃; And fourthly, when the moisture of the sample is less than or equal to 0.8, screening the sample.
6. An ultra-high nickel positive electrode material precursor, characterized in that the ultra-high nickel positive electrode material precursor is prepared by the preparation method of any one of claims 1-5; the ultra-high nickel positive electrode material precursor has at least one of the following characteristics: The chemical general formula of the ultra-high nickel anode material precursor is Ni 1-x-y-z Co x Mn y Ga z (OH) 2 , wherein 1-x-y-z is more than 0.9; Secondly, the primary particles of the ultra-high nickel anode material precursor are flaky; The third feature is that the length of primary particles of the ultra-high nickel anode material precursor is 50-70nm; fourthly, the width of primary particles of the ultra-high nickel anode material precursor is 10-20nm; Fifth, the secondary particles of the ultra-high nickel anode material precursor are spherical or spheroidic, and the particle size of the secondary particles is 2.5-3.5 mu m; And the average particle size of the ultra-high nickel anode material precursor is 2-3 mu m.
7. A positive electrode material, wherein the precursor of the positive electrode material is the ultra-high nickel positive electrode material precursor of claim 6.
8. A battery, characterized in that the battery has the positive electrode material according to claim 7.

Description

Ultra-high nickel positive electrode material precursor, preparation method thereof, positive electrode material and battery Technical Field The invention relates to the technical field of batteries, in particular to an ultra-high nickel positive electrode material precursor, a preparation method thereof, a positive electrode material and a battery. Background In recent years, lithium ion batteries have become research hot spots in the field of chemical power sources due to the characteristics of high voltage, large power, stable discharge voltage, wide application range, wide working range, long service life and the like. Since the capacity of a lithium ion battery is ultimately determined by the cathode material, research into the cathode material will be key to improving the overall performance of the lithium ion battery. The layered NCM ternary positive electrode material has the advantages of high specific capacity, low cost, long cycle life, no memory effect and the like, and is widely applied to various fields of digital codes, notebooks, electric automobiles and the like in recent years. Among the ternary positive electrode materials, the high-nickel ternary positive electrode material (LiNi 1-x-yCoxMnyO2, 1-x-y is larger than 0.6) has the advantages of high specific capacity, high compaction density, good multiplying power performance, low cost and the like, can meet the requirements of low cobalt and high energy density of the next generation of power batteries, and is one of the ternary positive electrode materials with potential. The main raw materials for producing the ternary positive electrode material are ternary precursors, and the sphericity, crystallinity, element proportion, specific surface area, particle size and the like of the ternary precursors can influence the performance of the ternary positive electrode material. The physical and chemical indexes of the precursor are related to ammonia concentration, stirring intensity, reaction temperature, pH value, reaction time, solid content, impurity content and the like, and also related to the synthesis process. In the NCM ternary precursor, nickel is mainly an electrochemical active element, the increase of nickel is helpful for improving the capacity of the material so as to improve the energy density, the existence of cobalt can reduce the electrochemical polarization of the material and improve the multiplying power characteristic of the material, the excessive high cobalt can reduce the reversible capacity, the manganese can ensure the structural stability and the thermal stability of the material, the existence of manganese can reduce the cost and improve the safety performance, and the excessive high manganese can easily destroy the original layered structure of the material. The nickel content in the material is higher, the energy density of the battery is higher, the service time of the battery after single charging can be greatly prolonged, the endurance mileage of the vehicle-mounted power battery is improved, the high-nickel power battery solves the problem of light weight of the battery, the space saving capability is far better than that of a common ternary battery, the use of cobalt is reduced due to the improvement of the nickel proportion, and the production cost is reduced to a certain extent. However, the high-nickel ternary precursor is easy to generate phase change under high voltage circulation, so that the circulation performance is poor, and the problems of the high-nickel ternary precursor are also greatly reduced to a certain extent, and the large-scale commercial production of the high-nickel ternary precursor is also greatly reduced. The cycling performance of lithium battery cathode materials is mainly related to the structure of the materials and the properties of the surfaces of the materials. The method has the advantages that the method can be modified by means of element doping or surface modification, for example, the problems of poor cycle performance and the like of the high-nickel ternary positive electrode material can be solved by means of ion doping, surface coating, electrolyte additives and the like. The doping of some elements can replace the position of Ni 2+ element in the positive electrode material so as to reduce the mixed discharge phenomenon of Li +/Ni2+, increase the interlayer spacing of the crystal structure so as to reduce the migration resistance of Li +, and simultaneously, can enhance the stability of the crystal structure or increase the specific capacity so as to improve the cycle stability of the ternary lithium ion battery. In the prior art, common doping elements are magnesium (Mg), aluminum (Al), titanium (Ti), zirconium (Zr), fluorine (F) and the like, and also some doping elements are gallium (Ga). The doping of the metal element is mostly realized in the sintering stage, but the doping is usually uneven in the sintering process, so that the final effect is difficult to en