WO2021042990A1 - 正极活性材料、其制备方法、正极极片、锂离子二次电池及其相关的电池模块、电池包和装置 - Google Patents
正极活性材料、其制备方法、正极极片、锂离子二次电池及其相关的电池模块、电池包和装置 Download PDFInfo
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Definitions
- This application belongs to the technical field of secondary batteries, and specifically relates to a positive electrode active material, a preparation method thereof, a positive electrode pole piece, a lithium ion secondary battery and related battery modules, battery packs and devices.
- Lithium-ion secondary battery is a kind of rechargeable battery, which mainly relies on the movement of lithium ions between the positive electrode and the negative electrode to work, and is a clean energy that is currently widely used.
- the positive electrode active material provides lithium ions that reciprocate between the positive and negative electrodes for the battery charging and discharging process. Therefore, the positive electrode active material is very important to the performance of the battery.
- Lithium nickel cobalt manganese oxide has a higher theoretical capacity, and a lithium ion secondary battery using lithium nickel cobalt manganese oxide as a positive electrode active material can expect to obtain a higher energy density.
- a lithium ion secondary battery using lithium nickel cobalt manganese oxide as a positive electrode active material can expect to obtain a higher energy density.
- how to make the lithium ion secondary battery have both higher energy density and good high temperature cycle performance has become a technical problem to be solved urgently.
- the first aspect of the present application provides a positive electrode active material, which includes lithium nickel cobalt manganese oxide.
- the molar content of nickel in the lithium nickel cobalt manganese oxide accounts for 60% to 90% of the total molar content of nickel, cobalt, and manganese.
- Ni-Co-Mn oxides belong to the space group The layered crystal structure; the transition metal layer of lithium nickel cobalt manganese oxide includes doping elements, and the relative deviation of the local mass concentration of the doping elements in the particles of the positive electrode active material is 20% or less; and the positive electrode active material is 78%
- the initial exothermic temperature of the main exothermic peak is 200° C. or more, and the integral area of the main exothermic peak is less than 100 J/g.
- the positive electrode active material provided in this application includes lithium nickel cobalt manganese oxide with high nickel content, which has higher charge and discharge voltage and specific capacity characteristics.
- the use of the positive electrode active material can enable lithium ion secondary batteries to have higher capacity performance And energy density.
- lithium nickel cobalt manganese oxide also includes doping elements, and the relative deviation of the local mass concentration of doping elements in the particles of the positive electrode active material is less than 20%, and the difference of the positive electrode active material in the 78% delithiation state In the scanning calorimetry spectrum, the initial exothermic temperature of the main exothermic peak is above 200°C, and the integral area of the main exothermic peak is below 100J/g, which can make the positive electrode active material have higher thermal stability and high temperature Cycle stability. Therefore, the use of the positive electrode active material of the present application can also enable the lithium ion secondary battery to have higher high-temperature cycle performance.
- the half-width of the main exothermic peak may be 30°C or less.
- the positive electrode active material satisfies the above conditions and can obtain higher thermal stability and high-temperature cycle stability, thereby further improving the high-temperature cycle performance of the lithium ion secondary battery.
- the peak temperature of the main exothermic peak may be 230°C or higher. Satisfying the above conditions can improve the thermal stability of the positive electrode active material, thereby improving the high-temperature cycle performance of the battery.
- the relative deviation of the local mass concentration of the doping element in the particles of the positive electrode active material is 15% or less.
- the battery using the positive electrode active material can obtain higher energy density and high-temperature cycle performance.
- the doping element when the positive electrode active material is in the 78% delithiation state, may have a valence of +3 or more, and optionally have a valence of +4, +5, +6, One or more of +7 and +8 valences.
- Doping elements with higher valence can effectively bind oxygen atoms, and can also increase the initial exothermic temperature and maximum exothermic temperature of the main exothermic peak in the DSC spectrum of the positive electrode active material after delithiation, and reduce the main exothermic peak
- the integral area and half-peak width of the positive electrode active material have higher thermal stability and high-temperature cycle stability, thereby further improving the energy density and high-temperature cycle performance of the battery.
- the doping element may include one or more of Al, Si, Ti, V, Ge, Se, Zr, Nb, Ru, Pd, Sb, Te, and W; optional , The doping element may include one or more of Al, Si, Ge, Se, Zr, Ru, Sb, Te, and W; optionally, the doping element may include Si, Ge, Se, Ru, Sb, One or more of Te and W.
- the positive electrode active material to meet the true density ⁇ true 4.6g / cm 3 ⁇ true ⁇ 4.9g / cm 3.
- the positive electrode active material can have a higher specific capacity, which can increase the energy density of the battery.
- the actual doping concentration ⁇ of the positive electrode active material may satisfy: 2300 ⁇ g/cm 3 ⁇ 49500 ⁇ g/cm 3 ; optionally, 3000 ⁇ g/cm 3 ⁇ 35000 ⁇ g/cm 3 ; Optionally, 14810 ⁇ g/cm 3 ⁇ 36710 ⁇ g/cm 3 .
- the actual doping concentration of the positive electrode active material is in an appropriate range, it can increase the initial exothermic temperature and the maximum exothermic temperature of the main exothermic peak in the DSC spectrum of the "78% delithiation state" of the positive active material, and reduce the main exothermic temperature.
- the integrated area and half-width of the thermal peak also ensure that the positive electrode active material has good lithium ion transport performance, thereby improving the energy density and high-temperature cycle performance of the battery.
- the deviation of the mass concentration of the doping element in the positive electrode active material relative to the average mass concentration of the doping element in the particles of the positive electrode active material is ⁇ 50%; optionally, ⁇ 30 %; further optional, ⁇ 20%.
- the positive electrode active material satisfies ⁇ within the above range, and its macroscopic and microscopic consistency is better.
- the expansion and contraction of the particles remain consistent, and the particle stability is high, which is conducive to higher capacity development and normal temperature and high temperature cycle performance. Therefore, the corresponding performance of the battery is also improved.
- the volume average particle size D v 50 of the positive electrode active material may be 5 ⁇ m to 20 ⁇ m, optionally 8 ⁇ m to 15 ⁇ m, and further optionally 9 ⁇ m to 11 ⁇ m.
- the D v 50 of the positive electrode active material is within the above range, which can improve the transmission and diffusion performance of lithium ions and electrons, thereby improving the cycle performance and rate performance of the lithium ion secondary battery.
- the positive electrode active material can also have a higher compaction density, which can increase the energy density of the battery.
- the specific surface area of the positive electrode active material may be 0.2m 2 /g ⁇ 1.5m 2 / g, alternatively it is 0.3m 2 / g ⁇ 1m 2 / g.
- the specific surface area of the positive electrode active material within the above range can improve the capacity and cycle life of the positive electrode active material, and can also improve the processing performance of the positive electrode slurry, so that the battery can obtain higher energy density and cycle performance.
- the tap density of the positive electrode active material may be 2.3 g/cm 3 to 2.8 g/cm 3 .
- the tap density of the positive electrode active material is within the above range, which is beneficial for the lithium ion secondary battery to have a higher energy density.
- the compact density of the positive electrode active material under a pressure of 5 tons may be 3.1 g/cm 3 to 3.8 g/cm 3 .
- the compaction density of the positive electrode active material is within the given range, which is beneficial for the lithium ion secondary battery to obtain higher energy density and cycle performance.
- the second aspect of the present application provides a method for preparing a positive electrode active material, which includes the following steps:
- the positive electrode active material precursor, the lithium source and the doping element precursor are mixed to obtain a mixture, wherein the positive electrode active material precursor is selected from the group consisting of oxides, hydroxides and carbonates containing Ni, Co and Mn One or more, and the molar content of nickel accounts for 60% to 90% of the total molar content of nickel, cobalt, and manganese;
- the positive electrode active material includes lithium nickel cobalt manganese oxide, and the lithium nickel cobalt manganese oxide has a space group The layered crystal structure;
- the transition metal layer of the lithium nickel cobalt manganese oxide includes a doping element, and the relative deviation of the local mass concentration of the doping element in the particles of the positive electrode active material is 20% or less;
- the initial exothermic temperature of the main exothermic peak is above 200°C, and the integral area of the main exothermic peak is below 100J/g .
- the preparation method provided in this application makes the obtained positive electrode active material include lithium nickel cobalt manganese oxide with high nickel content, while the lithium nickel cobalt manganese oxide also includes doping elements, and the local mass concentration of the doping elements in the particles of the positive electrode active material
- the relative deviation of the positive electrode active material is less than 20%, and the differential scanning calorimetry spectrum of the positive electrode active material in the 78% delithiation state, the initial exothermic temperature of the main exothermic peak is above 200 °C, and the main exothermic peak
- the integral area is 100 J/g or less, thereby enabling the lithium ion secondary battery using the positive electrode active material to have higher energy density and high-temperature cycle performance.
- the doping element precursor is selected from aluminum oxide, silicon oxide, titanium oxide, vanadium oxide, germanium oxide, selenium oxide, zirconium oxide, niobium oxide, ruthenium oxide One or more of palladium oxide, antimony oxide, tellurium oxide, and tungsten oxide; optionally, the doping element precursor is selected from Al 2 O 3 , SiO 2 , SiO, TiO 2 , TiO, V 2 O 5 , V 2 O 4 , V 2 O 3 , GeO 2 , SeO 2 , ZrO 2 , Nb 2 O 5 , NbO 2 , RuO 2 , PdO, Sb 2 O 5 , Sb 2 O 3 , One or more of TeO 2 , WO 2 , and WO 3.
- the atmosphere of the sintering process is an oxygen-containing atmosphere; optionally, the oxygen concentration of the sintering atmosphere is 70%-100%, and optionally 75%-95%.
- the temperature of the sintering treatment is 600°C to 1000°C, and optionally 700°C to 900°C.
- the sintering treatment time is 5h-25h, and optionally 10h-20h.
- the doping element precursor can be equally divided into L parts or arbitrarily divided into L parts, and divided into L batches for doping, where L is 1 to 5, and optionally 2 ⁇ 3.
- the options include: mixing the precursor of the positive electrode active material, the lithium source, and the first batch of doping element precursors, and performing the first sintering treatment; combining the product of the first sintering treatment with the second batch of doping elements The precursor is mixed, and the second sintering process is performed; and so on, until the product of the L-1 sintering process is mixed with the L batch of doping element precursors, and the L sintering process is performed to obtain Positive active material.
- the temperature of each sintering treatment is 600°C to 1000°C, optionally 700°C to 900°C, and further optionally 800°C to 850°C.
- the time for each sintering treatment is 3h-25h, and optionally 5h-10h.
- the total sintering treatment time is 5h-25h, optionally 15h-25h.
- a third aspect of the present application provides a positive pole piece, which includes a positive current collector and a positive active material layer disposed on the positive current collector, the positive active material layer includes the positive active material of the first aspect of the present application, or The positive electrode active material obtained by the preparation method of the second aspect of the present application.
- the lithium ion secondary battery using the same can have higher energy density and high-temperature cycle performance.
- a fourth aspect of the present application provides a lithium ion secondary battery, which includes the positive pole piece of the third aspect of the present application.
- the lithium ion secondary battery of the present application includes the positive pole piece, it can have higher energy density and high-temperature cycle performance.
- a fifth aspect of the present application provides a battery module, which includes the lithium ion secondary battery of the fourth aspect of the present application.
- a sixth aspect of the present application provides a battery pack, which includes the lithium ion secondary battery of the fourth aspect of the present application or the battery module of the fifth aspect of the present application.
- a seventh aspect of the present application provides a device, which includes at least one of the lithium ion secondary battery of the fourth aspect of the present application, the battery module of the fifth aspect of the present application, or the battery pack of the sixth aspect of the present application.
- the battery module, battery pack, and device of the present application include the lithium ion secondary battery of the present application, and thus have at least the same or similar effects as the lithium ion secondary battery.
- Fig. 1 is a spectrogram of the exothermic curve measured by differential scanning calorimetry (Differential Scanning Calorimeter, DSC) of a positive electrode active material according to an embodiment of the application, that is, the spectrogram of differential scanning calorimetry, referred to as DSC spectrogram .
- DSC differential Scanning Calorimeter
- Example 2 is a cross-sectional image of the positive electrode active material particles of Example 1, in which bright spots indicate doping elements, and the doping elements are uniformly distributed in the particles.
- FIG. 3 is a schematic diagram of the location of the relative deviation test of the local mass concentration of the doping element in the positive electrode active material particles of Examples 1-21 and Comparative Examples 1-7.
- Fig. 4 is a schematic diagram of an embodiment of a lithium ion secondary battery.
- Fig. 5 is an exploded view of Fig. 4.
- Fig. 6 is a schematic diagram of an embodiment of a battery module.
- Fig. 7 is a schematic diagram of an embodiment of a battery pack.
- Fig. 8 is an exploded view of Fig. 7.
- FIG. 9 is a schematic diagram of an embodiment of a device in which a lithium ion secondary battery is used as a power source.
- any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, and any upper limit can be combined with any other upper limit to form an unspecified range.
- every point or single value between the end points of the range is included in the range. Therefore, each point or single numerical value can be used as its own lower limit or upper limit, combined with any other point or single numerical value, or combined with other lower or upper limits to form an unspecified range.
- the term "or” is inclusive.
- the phrase "A or (or) B” means “A, B, or both A and B.” More specifically, any of the following conditions satisfy the condition "A or B”: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists) ; Or both A and B are true (or exist).
- the first aspect of the present application provides a positive electrode active material, which includes lithium nickel cobalt manganese oxide.
- the molar content of nickel in the lithium nickel cobalt manganese oxide accounts for 60% to 90% of the total molar content of nickel, cobalt, and manganese.
- Ni-Co-Mn oxides belong to the space group
- the initial exothermic temperature of the main exothermic peak is 200°C or more, and the integral area of the main exothermic peak is 100 J/g or less.
- the local mass concentration of the doping element in the particles of the positive electrode active material is the mass concentration of the doping element in the finite volume element at any selected location in the particle, which can be determined by EDX (Energy Dispersive X-Ray Spectroscopy , Energy dispersive X-ray spectrometer) or EDS element analysis combined with TEM (Transmission Electron Microscope) or SEM (Scanning Electron Microscope) single-point scanning test element concentration distribution or other similar methods.
- EDX Electronicgy Dispersive X-Ray Spectroscopy , Energy dispersive X-ray spectrometer
- EDS element analysis combined with TEM (Transmission Electron Microscope) or SEM (Scanning Electron Microscope) single-point scanning test element concentration distribution or other similar methods.
- the mass concentrations of doping elements in ⁇ g/g at different positions in the particles of the positive electrode active material are respectively denoted as ⁇ 1 , ⁇ 2 , ⁇ 3 , ..., ⁇ n , where n is a positive integer greater than 15.
- the average mass concentration of doping elements in the particles of the positive electrode active material is the mass concentration of the doping elements in single or multiple particles of the positive electrode active material.
- the element concentration distribution can be tested by EDX or EDS element analysis combined with TEM or SEM surface scanning Or other similar ways to get it. When the EDX or EDS element analysis is combined with the TEM or SEM surface scanning method to test the element concentration distribution, the test surface includes all the test sites in the single-point test.
- the average mass concentration of doped elements in the particles of the positive electrode active material is recorded as The unit is ⁇ g/g.
- “78% delithiation state” refers to the state when the molar content of lithium extracted from the positive electrode active material accounts for 78% of the theoretical lithium content during the charging process of the battery.
- a “full charge state” is generally set, and a corresponding “charging cut-off voltage” is set to ensure the safe use of the battery.
- “Fully charged state” means that the state of charge (SOC) of the secondary battery is 100%.
- SOC state of charge
- the “full charge state” or “charging cut-off voltage” will have certain differences due to the difference in the positive electrode active material or the difference in safety requirements.
- the delithiation state of the positive electrode active material is generally around the "78% delithiation state" to ensure normal use.
- the corresponding relationship between the "delithiation state” and the charging voltage is combined to obtain the positive electrode active material in the "78% delithiation state" for research.
- a series of batteries using the positive electrode active material will be charged to 2.8V, 2.9V, 3.0V, 3.1V, 3.2V, 3.3V,...4.0V, 4.1V, 4.2V, at a rate of 0.1C, respectively.
- the positive pole piece of the battery is removed, the electrolyte is removed by washing, the positive electrode active material is digested, and the inductively coupled plasma-emission spectrometer (inductively coupled Plasma-Optical Emission spectrometers, ICP-OES) test the mass concentration of Li, transition metals (Ni, Co, Mn), and O elements of the positive electrode active material, calculate the stoichiometric ratio of each element of the positive electrode active material under the charging voltage, and convert it to get The chemical formula of the positive electrode active material at the charging voltage, and then the charging voltage corresponding to the "78% delithiation state" is obtained.
- ICP-OES inductively coupled Plasma-Optical Emission spectrometers
- the battery containing the positive electrode active material to be tested is charged to the voltage corresponding to the "78% delithiation state", and then the positive electrode active material in the "78% delithiation state" can be obtained for further study.
- Fig. 1 shows a DSC spectrum of a positive electrode active material as an example.
- the DSC spectrum is a graph drawn with heat flow rate as the ordinate and temperature as the abscissa.
- the main exothermic peak is the peak with the largest integrated area in the DSC spectrum. It is the exothermic peak produced by the irreversible phase transition of the layered phase structure caused by the oxygen release of the positive electrode active material.
- the onset exothermic temperature of the main exothermic peak is the intersection A between the tangent to the maximum slope point on the low temperature side of the main exothermic peak and the extension line of the baseline ef before the peak (that is, the extrapolation starting point) A.
- the integral area of the main exothermic peak is the area of the area enclosed by the exothermic peak and the inscribed baseline fg, which is used to characterize the heat emitted by the unit weight of the positive electrode active material in this interval.
- the positive electrode active material in the embodiment of the present application includes lithium nickel cobalt manganese oxide, and the molar content of nickel accounts for 60% to 90% of the total molar content of nickel, cobalt, and manganese.
- the lithium nickel cobalt manganese oxide with high nickel content has higher charge and discharge voltage and specific capacity characteristics, so that the lithium ion secondary battery using it can exhibit higher capacity performance and energy density.
- the lithium nickel cobalt manganese oxide of the embodiment of the present application further includes a doping element, and the relative deviation ⁇ of the local mass concentration of the doping element in the particles of the positive electrode active material is 20% or less.
- the distribution of doping elements in the positive electrode active material particles is uniform, and the properties inside the particles remain consistent.
- the doping elements can improve the structural stability of each position of the particle, and inhibit the oxygen release and structural phase change at each position of the particle , It is beneficial to increase the initial exothermic temperature of the main exothermic peak in the DSC spectrum of the "78% delithiation state" positive electrode active material, and reduce the integral area of the main exothermic peak.
- the onset exothermic temperature of the main exothermic peak is 200°C or higher, and may further be 205°C or higher, 207°C or higher, or 210°C or higher.
- the initial exothermic temperature of the main exothermic peak is relatively high, so that the positive electrode active material has high structural stability during high temperature cycling and heating and heating conditions and always maintains a strong electrochemically active layered phase State, where the oxygen atoms are not easy to leave the original lattice position.
- the positive electrode active material is not prone to irreversible structural phase change, so that it can exhibit higher thermal stability and high-temperature cycle stability, thereby improving the high-temperature cycle performance and safety performance of the lithium ion secondary battery.
- the integrated area of the main exothermic peak is less than 100J/g, and can further be less than 85J/g, less than 74J/g, less than 67J/g, 55J/g Below, or below 48J/g.
- the integral area of the main exothermic peak is small, that is, the amount of heat released by the positive electrode active material during high temperature cycling and heating conditions is reduced, indicating that the positive electrode active material has irreversible reactions or structural failures during high temperature cycling and heating conditions. Smaller.
- the thermal stability and high-temperature cycle stability of the positive electrode active material are effectively improved, which can significantly improve the high-temperature cycle performance and safety performance of the lithium-ion secondary battery.
- the migration and diffusion capacity of lithium ions in different areas inside the particles is at the same level, which enables the positive electrode active material to have higher lithium ion transport performance, which is beneficial to improve the capacity performance and energy of the battery.
- Density and cycle performance In the uniformly doped positive electrode active material, the structural stability and anti-deformation ability of the particles are close, so that the stress distribution in the particles is uniform. The particles of the positive electrode active material are not prone to cracks, and prevent side reactions and deterioration of capacity and cycle performance caused by the fresh surface exposed by the cracks, thereby further improving the high-temperature cycle performance of the battery.
- the use of the positive electrode active material of the embodiment of the present application enables the lithium ion secondary battery to simultaneously take into account higher capacity performance, energy density, and high-temperature cycle performance.
- the lithium nickel cobalt manganese oxide includes doping elements, and the relative deviation ⁇ of the local mass concentration of the doping elements in the particles of the positive electrode active material is less than 20%, which can also improve the DSC spectrum of the "78% delithiation state" of the positive electrode active material In the figure, the maximum exothermic temperature of the main exothermic peak and reduce the half-width of the main exothermic peak.
- the half-value width of the main exothermic peak can be selected to be 30°C or less, and further optionally 28°C or less.
- the half-width of the main exothermic peak is the peak width at half of the peak height mn
- n is the intersection of the peak top m of the main exothermic peak as the intersection of a straight line perpendicular to the abscissa and the inscribed baseline fg.
- the half-width of the main exothermic peak is within the stated range, that is, the irreversible reaction or structural damage of the "78% delithiation state" positive electrode active material is further reduced during the high temperature cycle process and under heating and heating conditions, and the positive electrode active material
- the thermal stability and high-temperature cycle stability are further improved, thereby further improving the performance of the lithium ion secondary battery.
- the half-width of the main exothermic peak is within the above range, which also means that the doping modification of the positive electrode active material does not produce obvious new phases.
- the doping element is basically at one of the nickel site, manganese site, and cobalt site. With multiple doping and substitution, the positive electrode active material maintains a good layered crystal structure.
- the positive electrode active material can provide a good carrier for the deintercalation of lithium ions, is beneficial to the intercalation and deintercalation of lithium ions, prevents reversible lithium ions from being consumed on the electrode surface or in the electrolyte, and effectively reduces the irreversible capacity, thereby making the positive electrode active material more effective. High initial capacity and cycle capacity retention rate, thereby improving the battery's energy density and normal temperature and high temperature cycle performance.
- the peak temperature of the main exothermic peak can be selected to be 225°C or more, and further optionally 230°C or more.
- Such positive electrode active materials are not prone to oxygen release during heating and high temperature cycles, and effectively inhibit the irreversible phase transition of the positive electrode active material after delithiation, thereby improving the thermal stability of the positive electrode active material, and further improving the high temperature cycle of the battery performance.
- the relative deviation ⁇ of the local mass concentration of the doping element in the particles of the positive electrode active material is 15% or less, further optionally 12% or less, and optionally 10% or less.
- the battery using the positive electrode active material can obtain higher energy density and high-temperature cycle performance.
- the doping element may be selected from one of transition metal elements other than nickel, cobalt, and manganese, and elements from groups IIA to VIA other than carbon, nitrogen, oxygen, and sulfur. kind or more.
- the doping element in the positive electrode active material in the "78% delithium state", has a valence of +3 or more, and further optionally has a valence of more than +3.
- the doping element in the "78% delithiation state" of the positive electrode active material, has one or more valences of +4, +5, +6, +7, and +8, and for example, One or more valences among +4 valence, +5 valence, and +6 valence.
- the doping element with higher valence has a stronger ability to bond with oxygen atoms, that is, the bond energy with oxygen atoms is larger, which can effectively bind oxygen atoms and prevent the positive electrode active material from heating up and high temperature cycling process after delithiation Oxygen release occurs during the process, the irreversible structural phase transition is suppressed, the initial exothermic temperature and maximum exothermic temperature of the main exothermic peak in the DSC spectrum of the positive electrode active material after delithiation are increased, and the integral area and half of the main exothermic peak are reduced. Peak width.
- the positive electrode active material can have high thermal stability and high temperature cycle stability, thereby further improving the energy density and high temperature cycle performance of the battery.
- Doping elements with higher valence can also contribute more electrons to the positive electrode active material, which can support the positive electrode to release more lithium ions, which further improves the energy density of the battery.
- the doping element has a valence state greater than +3, which exceeds the average valence state (+3 valence) of nickel, cobalt and manganese in lithium nickel cobalt manganese oxide, and the number of electrons contributed to the positive electrode active material is further increased. , Which can further improve the capacity and energy density of the battery.
- the battery containing the positive electrode active material to be tested can be charged to the voltage corresponding to the "78% delithiation state", and then the battery can be disassembled to obtain the "78% delithiation state" positive electrode active material.
- the valence of the doping element M in the "78% delithiation state" positive electrode active material can be measured by X-ray photoelectron spectroscopy (XPS). More accurate, it can be measured by synchrotron radiation photoelectron spectroscopy (SRPES).
- the doping element may include one or more of Al, Si, Ti, V, Ge, Se, Zr, Nb, Ru, Pd, Sb, Te, and W.
- the doping element may include one or more of Al, Si, Ge, Se, Zr, Ru, Sb, Te, and W.
- the doping element may include one or more of Si, Ge, Se, Ru, Sb, Te, and W.
- the positive electrode active material the true doping concentration of ⁇ 1500 ⁇ g / cm 3 ⁇ 60000 ⁇ g / cm 3 .
- 2300 ⁇ g/cm 3 ⁇ 49500 ⁇ g/cm 3 .
- 3000 ⁇ g/cm 3 ⁇ 35000 ⁇ g/cm 3 .
- 14810 ⁇ g/cm 3 ⁇ 36710 ⁇ g/cm 3 .
- 24900 ⁇ g/cm 3 ⁇ 25510 ⁇ g/cm 3 .
- ⁇ is the actual doping concentration of the positive electrode active material, and the unit is ⁇ g/cm 3 .
- ⁇ true positive electrode active material the true density in units of g / cm 3, which is equal to the ratio of the mass and the true volume of the positive electrode active material of the positive electrode active material, wherein the true volume is the actual volume of the solid material, not including the positive electrode active material particles And the pores between each other.
- ⁇ true can be measured by using instruments and methods known in the art, for example, the gas volume method can be performed by using a powder true density tester.
- the mass concentration of the doping element in the positive electrode active material in ⁇ g/g that is, the mass of the doping element contained in each gram of the positive electrode active material. among them, Represents the content of doping elements in the overall macroscopic positive electrode active material, including the doping elements doped into the positive electrode active material particles, the doping elements enriched in other phases on the surface of the positive electrode active material particles, and the doping elements located between the positive electrode active material particles. Doping elements. It can be measured by the solution absorption spectrum of the positive electrode active material, such as ICP (Inductive Coupled Plasma Emission Spectrometer), XAFS (X-ray absorption fine structure spectroscopy, X-ray absorption fine structure spectroscopy), etc.
- ICP Inductive Coupled Plasma Emission Spectrometer
- XAFS X-ray absorption fine structure spectroscopy, X-ray absorption fine structure spectroscopy
- the actual doping concentration of the positive electrode active material is within an appropriate range, which can increase the initial exothermic temperature and maximum exothermic temperature of the main exothermic peak in the DSC spectrum of the "78% delithiation state" positive active material, and reduce the main exothermic temperature.
- the integral area and half-peak width of the exothermic peak also ensure that the positive electrode active material has a good layered crystal structure, and that the positive electrode active material has good lithium ion insertion/extraction performance, thereby enabling the positive electrode active material to have a higher
- the initial capacity and cycle capacity retention rate can improve the energy density and high temperature cycle performance of the battery.
- the true doping concentration of the positive electrode active material is within the above range, which also ensures that the doping element is doped in the transition metal layer, prevents it from entering the lithium layer, and ensures that the positive electrode active material particles have a high lithium ion transport and diffusion ability, so that The battery has high capacity and cycle performance.
- the mass concentration of the doping element in the positive electrode active material is Relative to the average mass concentration of doped elements in the cathode active material particles
- the deviation ⁇ 50%.
- the mass concentration of doped elements in the positive electrode active material Relative to the average mass concentration of doped elements in the cathode active material particles
- the deviation ⁇ of is calculated by the following formula (3):
- the positive electrode active material satisfies ⁇ within the above range, which means that the doping elements are smoothly incorporated into the positive electrode active material particles, the doping elements distributed in other phases on the surface of the positive electrode active material particles, and the doping elements embedded in the gaps of the positive electrode active material particles.
- the content of miscellaneous elements is small, the macroscopic and microscopic consistency of the cathode active material is better, and the structure is uniform.
- the expansion and contraction degree of the particles remains consistent, and the particle stability is high, which is conducive to higher capacity development and normal temperature and high temperature cycle performance.
- the positive electrode active material of the embodiment of the present application can optionally be uniformly doped within the above-mentioned true doping concentration range to ensure the consistency of the microscopic distribution and the macroscopic content of the doping elements, which can more effectively improve the thermal stability of the positive electrode active material And high temperature cycle stability, so as to better improve the battery's energy density and high temperature cycle performance.
- the positive electrode active material to meet the true density ⁇ true 4.6g / cm 3 ⁇ true ⁇ 4.9g / cm 3. This can make the positive electrode active material have a higher specific capacity, thereby improving the capacity performance and energy density of the battery.
- the molar content of nickel in the lithium nickel cobalt manganese oxide accounts for 70% to 90%, such as 75% to 85%, of the total molar content of nickel, cobalt, and manganese.
- the positive electrode active material has higher specific capacity characteristics and can improve the capacity performance and energy density of the lithium ion secondary battery.
- lithium nickel cobalt manganese oxides can satisfy the chemical formula Li 1+a [Ni x Co y Mn z M b ]O 2 , where M is a doping element, which has a positive effect on nickel sites, cobalt sites, and manganese sites.
- M is a doping element, which has a positive effect on nickel sites, cobalt sites, and manganese sites.
- One or more doping substitutions, and 0.6 ⁇ x ⁇ 0.9, 0 ⁇ y ⁇ 0.3, 0 ⁇ z ⁇ 0.3, 0 ⁇ a ⁇ 0.2, 0 ⁇ b ⁇ 0.3, x+y+z+b 1.
- the use of the high nickel ternary positive electrode active material can enable the lithium ion secondary battery to have higher capacity performance, energy density, and cycle performance at room temperature and high temperature.
- the high-nickel ternary positive electrode active material has high energy density and good structural stability, which is beneficial to enable the battery to have high energy density and long cycle life.
- M is selected from one or more of Al, Si, Ti, V, Ge, Se, Zr, Nb, Ru, Pd, Sb, Te, and W.
- M may include one or more of Al, Si, Ge, Se, Zr, Ru, Sb, Te, and W.
- M may include one or more of Si, Ge, Se, Ru, Sb, Te, and W.
- the doping element M ensures that the high nickel ternary cathode active material has high thermal stability and high temperature cycle stability, and improves the overall performance of the battery.
- the doping element M due to the higher valence of the doping element M, it can contribute more electrons in the positive electrode active material, and support the high nickel ternary positive electrode active material to release more lithium ions, thereby improving the capacity performance and energy density of the battery.
- the use of the high nickel ternary positive electrode active material can enable the lithium ion secondary battery to have higher capacity performance, energy density, and cycle performance at room temperature and high temperature.
- the high-nickel ternary positive electrode active material has high energy density and good structural stability, which is beneficial to enable the battery to have high energy density and long cycle life.
- M' is selected from one or more of Al, Si, Ti, V, Ge, Se, Zr, Nb, Ru, Pd, Sb, Te, and W.
- M' may include one or more of Al, Si, Ge, Se, Zr, Ru, Sb, Te, and W.
- M' may include one or more of Si, Ge, Se, Ru, Sb, Te, and W.
- the doping element M' ensures that the high nickel ternary positive electrode active material has high thermal stability and high temperature cycle stability, and improves the overall performance of the battery.
- the doping element M' can support the high nickel ternary positive electrode active material to release more lithium ions, and improve the capacity performance and energy density of the lithium ion secondary battery.
- the various lithium nickel cobalt manganese oxides in the above examples can be used independently for the positive electrode active material, or a combination of any two or more kinds of lithium nickel cobalt manganese oxides can be used for the positive electrode active material.
- the volume average particle size D v 50 of the positive electrode active material may be 5 ⁇ m-20 ⁇ m, further may be 8 ⁇ m-15 ⁇ m, and may also be 9 ⁇ m-11 ⁇ m. If the D v 50 of the positive electrode active material is within the above range, the migration path of lithium ions and electrons in the material is relatively short, which can further improve the transmission and diffusion performance of lithium ions and electrons in the positive electrode active material, reduce battery polarization, and improve lithium The cycle performance and rate performance of the ion secondary battery; in addition, it can also make the positive electrode active material have a higher compaction density and improve the energy density of the battery.
- the D v 50 of the positive electrode active material within the above range is also beneficial to reduce the side reaction of the electrolyte on the surface of the positive electrode active material, and reduce the agglomeration between the positive electrode active material particles, thereby improving the normal temperature and high temperature cycle performance of the positive electrode active material. Safety performance.
- the specific surface area of the positive electrode active material is selected to 0.2m 2 /g ⁇ 1.5m 2 / g, further optionally is 0.3m 2 / g ⁇ 1m 2 / g.
- the specific surface area of the positive electrode active material is within the above range, which ensures that the positive electrode active material has a higher active specific surface area, and at the same time, it is also beneficial to reduce the side reaction of the electrolyte on the surface of the positive electrode active material, thereby improving the capacity and circulation of the positive electrode active material. Life; In addition, it can also inhibit the agglomeration of particles between the particles of the positive electrode active material during the preparation of the slurry and the charging and discharging process, which can improve the energy density and cycle performance of the battery.
- the tap density of the positive electrode active material can be selected from 2.3 g/cm 3 to 2.8 g/cm 3 .
- the tap density of the positive electrode active material is within the above range, which is beneficial for the lithium ion secondary battery to have higher capacity performance and energy density.
- the compacted density of the positive electrode active material under a pressure of 5 tons can be selected from 3.1 g/cm 3 to 3.8 g/cm 3 .
- the higher compaction density of the positive electrode active material is conducive to making the lithium ion secondary battery have higher capacity performance and energy density, and at the same time has good normal temperature cycle performance and high temperature cycle performance.
- the morphology of the positive electrode active material particles is one or more of spheres and spheroids.
- the positive active material includes secondary particles aggregated from primary particles.
- the aforementioned “particles” include secondary particles.
- the volume average particle size D v 50 of the positive electrode active material has a well-known meaning in the art, and is also referred to as the median particle size, which represents the particle size corresponding to 50% of the volume distribution of the positive electrode active material particles.
- the D v 50 of the positive electrode active material can be measured by a well-known instrument and method in the art, such as a laser particle size analyzer (such as the Mastersizer 3000 of Malvern Instruments Co., Ltd., UK).
- the specific surface area of the positive electrode active material is a well-known meaning in the art, and it can be measured by instruments and methods known in the art. For example, it can be measured by the nitrogen adsorption specific surface area analysis test method and calculated by the BET (Brunauer Emmett Teller) method, where The nitrogen adsorption specific surface area analysis test can be performed by the NOVA 2000e specific surface area and pore size analyzer of the United States Kanta Company.
- the test method is as follows: take 8.000g ⁇ 15.000g of positive electrode active material in a weighed empty sample tube, stir and weigh the positive electrode active material, and put the sample tube into the NOVA 2000e degassing station for degassing , Weigh the total mass of the positive electrode active material and the sample tube after degassing, and calculate the mass G of the positive electrode active material after degassing by subtracting the mass of the empty sample tube from the total mass.
- the tap density of the positive electrode active material is a well-known meaning in the art, and can be measured with a well-known instrument and method in the art, for example, a tap density meter (such as FZS4-4B type) can be conveniently measured.
- a tap density meter such as FZS4-4B type
- the compaction density of the positive electrode active material is a well-known meaning in the art, and can be measured with a well-known instrument and method in the art, such as an electronic pressure tester (such as UTM7305).
- the preparation method includes:
- the positive electrode active material precursor, the lithium source, and the doping element precursor are mixed, and sintered to obtain the positive electrode active material.
- the precursor of the positive electrode active material may be one or more of oxides, hydroxides, and carbonates containing Ni, Co, and Mn in a stoichiometric ratio, for example, hydrogen containing Ni, Co, and Mn in a stoichiometric ratio. Oxide.
- the positive electrode active material precursor can be obtained by a method known in the art, for example, prepared by a co-precipitation method, a gel method, or a solid phase method.
- the Ni source, Co source, and Mn source are dispersed in a solvent to obtain a mixed solution; the mixed solution, strong alkali solution and complexing agent solution are simultaneously pumped into a stirred reactor by means of continuous co-current reaction. , Control the pH of the reaction solution to be 10-13, the temperature in the reactor is 25°C to 90°C, and pass inert gas protection during the reaction; after the reaction is completed, it is aged, filtered, washed and vacuum dried to obtain Ni , Co and Mn hydroxides.
- the Ni source may be a soluble nickel salt, such as one or more of nickel sulfate, nickel nitrate, nickel chloride, nickel oxalate, and nickel acetate, and another example, one or more of nickel sulfate and nickel nitrate, Another example is nickel sulfate;
- the Co source can be a soluble cobalt salt, such as one or more of cobalt sulfate, cobalt nitrate, cobalt chloride, cobalt oxalate, and cobalt acetate, and another example is cobalt sulfate and cobalt nitrate.
- the Mn source may be a soluble manganese salt, such as one or more of manganese sulfate, manganese nitrate, manganese chloride, manganese oxalate and manganese acetate, and another example is sulfuric acid One or more of manganese and manganese nitrate, and another example is manganese sulfate.
- the strong base may be one or more of LiOH, NaOH, and KOH, for example, NaOH.
- the complexing agent may be one or more of ammonia, ammonium sulfate, ammonium nitrate, ammonium chloride, ammonium citrate, and disodium ethylenediaminetetraacetate (EDTA), for example, ammonia.
- the solvents of the mixed solution, strong base solution and complexing agent solution are each independently deionized water, methanol, ethanol, acetone, and isopropyl.
- the solvents of the mixed solution, strong base solution and complexing agent solution are each independently deionized water, methanol, ethanol, acetone, and isopropyl.
- the inert gas introduced during the reaction is, for example, one or more of nitrogen, argon, and helium.
- the lithium source can be lithium oxide (Li 2 O), lithium phosphate (Li 3 PO 4 ), lithium dihydrogen phosphate (LiH 2 PO 4 ), lithium acetate (CH 3 COOLi), lithium hydroxide (LiOH), lithium carbonate ( One or more of Li 2 CO 3 ) and lithium nitrate (LiNO 3 ). Further, the lithium source is one or more of lithium carbonate, lithium hydroxide, and lithium nitrate. Furthermore, the lithium source is lithium carbonate.
- the doping element precursor may be one or more of doping element oxides, nitric acid compounds, carbonic acid compounds, hydroxide compounds, and acetic acid compounds.
- oxides of doping elements such as aluminum oxide (such as Al 2 O 3 ), silicon oxide (such as SiO 2 , SiO, etc.), titanium oxide (such as TiO 2 , TiO, etc.), vanadium oxide (such as V 2 O 5 , V 2 O 4 , V 2 O 3, etc.), germanium oxide (such as GeO 2, etc.), selenium oxide (such as SeO 2, etc.), zirconium oxide (such as ZrO 2, etc.), niobium oxide (such as Nb 2 O 5 , NbO 2 etc.), ruthenium oxide (such as RuO 2 ), palladium oxide (such as PdO, etc.), antimony oxide (such as Sb 2 O 5 , Sb 2 O 3, etc.), tellurium oxide (such as TeO 2 ) and tungsten oxide (Such as
- the precursor of the positive electrode active material, the lithium source and the precursor of the doping element can be mixed by a ball mill mixer or a high-speed mixer.
- the mixed materials are put into the atmosphere sintering furnace for sintering.
- the sintering atmosphere is an oxygen-containing atmosphere, for example, an air atmosphere or an oxygen atmosphere.
- the oxygen concentration of the sintering atmosphere is 70%-100%, such as 75%-95%.
- the sintering temperature is, for example, 600°C to 1000°C.
- the sintering temperature is 700°C to 900°C. This is conducive to making the doping elements have a higher uniformity of distribution.
- the sintering time can be adjusted according to actual conditions, for example, 5h-25h, and for example 10h-20h.
- the positive electrode active material there are a variety of theoretically feasible ways to control the DSC onset exothermic temperature and exothermic peak area of the nickel cobalt manganese oxide positive electrode active material, such as the types of doping elements and doping. Element content, sintering time, sintering temperature, number of sintering and oxygen concentration during sintering. In this application, some measures of solid-phase sintering doping methods are listed.
- the obtained lithium nickel cobalt The molar content of nickel in manganese oxide accounts for 60% to 90% of the total molar content of nickel, cobalt and manganese, and it belongs to the space group
- the layered crystal structure of the transition metal layer includes doping elements, and the relative deviation of the local mass concentration of the doping elements in the particles of the positive electrode active material is less than 20%; and the positive electrode material is delithified to 78% when tested under the delithiation state
- the initial exothermic temperature of the main exothermic peak is 200° C. or more, and the integral area of the main exothermic peak is 100 J/g or less. It should be understood that the method described in this specification is only for explaining the application, not for limiting the application.
- the doping element precursor may be divided into L batches for doping of the doping element, where L may be 1 to 5, such as 2 to 5, or 2 to 3.
- the preparation method of the positive electrode active material may include the following steps: mixing the positive electrode active material precursor, the lithium source, and the first batch of doping element precursors, and performing the first sintering treatment; The product of the second sintering treatment is mixed with the second batch of doping element precursors, and the second sintering treatment is carried out; and so on, until the products of the L-1 sintering treatment are combined with the L batch of doping element precursors The body is mixed and subjected to the L-th sintering treatment to obtain a positive electrode active material.
- the doping element precursor can be equally divided into L parts or arbitrarily divided into L parts to perform L batches of doping.
- the temperature of each sintering process is the same or different.
- the time of each sintering treatment is the same or different. Those skilled in the art can adjust the sintering temperature and time according to the type and amount of doping elements.
- the temperature of each sintering treatment may be 600°C to 1000°C, such as 700°C to 900°C, and then 800°C to 850°C.
- the time of each sintering treatment can be 3h-25h, such as 5h-10h.
- the total sintering time can be 5h-25h, such as 15h-25h.
- the doping uniformity can be improved by increasing the sintering temperature and/or prolonging the sintering time.
- the sintered product can also be crushed and sieved to obtain a positive electrode active material with optimized particle size distribution and specific surface area.
- a particle crusher There are no special restrictions on the crushing method, and it can be selected according to actual needs, such as using a particle crusher.
- This application provides a positive electrode sheet, which uses any one or several positive electrode active materials of this application.
- the lithium ion secondary battery can take into account both good room temperature and high temperature cycle performance and higher energy density at the same time.
- the positive pole piece includes a positive electrode current collector and a positive electrode active material layer provided on at least one surface of the positive electrode current collector.
- the positive electrode current collector includes two opposite surfaces in its thickness direction, and the positive electrode active material layer is stacked on either or both of the two surfaces of the positive electrode current collector.
- the positive active material layer includes any one or several positive active materials of the present application.
- the positive electrode active material layer may further include a conductive agent and a binder.
- a conductive agent and a binder This application does not specifically limit the types of conductive agents and binders in the positive active material layer, and can be selected according to actual needs.
- the conductive agent may be one or more of graphite, superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers;
- the binder may be styrene-butadiene Rubber (SBR), water-based acrylic resin, carboxymethyl cellulose (CMC), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinyl butyral (PVB) ), ethylene-vinyl acetate copolymer (EVA), vinylidene fluoride-tetrafluoroethylene-propylene terpolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene terpolymer, tetrafluoroethylene-hexafluoropropylene
- SBR styrene-butadiene Rubber
- EVA ethylene-vinyl acetate copoly
- the positive electrode current collector can be a metal foil or porous metal plate with good electrical conductivity and mechanical properties, and its material can be one or more of aluminum, copper, nickel, titanium, silver, and their respective alloys.
- the positive electrode current collector is, for example, aluminum foil.
- the positive pole piece can be prepared according to conventional methods in the art. For example, disperse the positive electrode active material, conductive agent, and binder in a solvent.
- the solvent can be N-methylpyrrolidone (NMP) and deionized water to form a uniform positive electrode slurry.
- NMP N-methylpyrrolidone
- the positive electrode slurry is coated on the positive electrode current collector. Above, after drying, rolling and other processes, the positive pole piece is obtained.
- the present application provides a lithium ion secondary battery, which includes a positive pole piece, a negative pole piece, a separator and an electrolyte, wherein the positive pole piece is any positive pole piece of the application.
- the lithium ion secondary battery adopts the positive pole piece of the present application, it can take into account good room temperature and high temperature cycle performance and high energy density at the same time.
- the negative pole piece may be a metal lithium piece.
- the negative electrode piece may further include a negative electrode current collector and a negative electrode active material layer provided on at least one surface of the negative electrode current collector.
- the negative electrode current collector includes two opposite surfaces in the thickness direction of the negative electrode current collector, and the negative electrode active material layer is stacked on either or both of the two surfaces of the negative electrode current collector.
- the anode active material layer includes an anode active material.
- the embodiments of the present application do not specifically limit the types of negative electrode active materials, and can be selected according to actual needs.
- the negative active material layer may further include a conductive agent and a binder.
- a conductive agent is one or more of graphite, superconducting carbon, acetylene black, carbon black, Ketjen black, carbon dots, carbon nanotubes, graphene, and carbon nanofibers
- the binder is styrene butadiene rubber (SBR), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinyl butyral (PVB), and one or more of water-based acrylic resins.
- the negative active material layer may also optionally include a thickener, such as sodium carboxymethyl cellulose (CMC-Na).
- a thickener such as sodium carboxymethyl cellulose (CMC-Na).
- the negative electrode current collector can be a metal foil or porous metal plate with good electrical conductivity and mechanical properties, and its material can be one or more of copper, nickel, titanium, iron, and their respective alloys.
- the negative electrode current collector is, for example, copper foil.
- the negative pole piece can be prepared according to conventional methods in the art. For example, disperse the negative electrode active material, conductive agent, binder and thickener in a solvent.
- the solvent can be N-methylpyrrolidone (NMP) or deionized water to form a uniform negative electrode slurry, and then coat the negative electrode slurry.
- NMP N-methylpyrrolidone
- the electrolyte may be a solid electrolyte, such as a polymer electrolyte, an inorganic solid electrolyte, etc., but it is not limited thereto. Electrolyte can also be used as the electrolyte.
- a solvent and a lithium salt dissolved in the solvent are included.
- the solvent may be a non-aqueous organic solvent, such as ethylene carbonate (EC), propylene carbonate (PC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), dimethyl carbonate (DMC) , Dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethylene propyl carbonate (EPC), methyl formate (MF), methyl acetate (MA), ethyl acetate (EA), propyl acetate ( One or more of PA), methyl propionate (MP), ethyl propionate (EP), propyl propionate (PP), methyl butyrate (MB) and ethyl butyrate (EB),
- EC ethylene carbonate
- PC propylene carbonate
- EMC diethyl carbonate
- DMC dimethyl carbonate
- DPC Dipropyl carbonate
- MPC methyl propyl carbonate
- EPC ethylene propyl carbonate
- EPC
- the lithium salt can be LiPF 6 (lithium hexafluorophosphate), LiBF 4 (lithium tetrafluoroborate), LiClO 4 (lithium perchlorate), LiAsF 6 (lithium hexafluoroarsenate), LiFSI (lithium bisfluorosulfonimide), LiTFSI (Lithium bistrifluoromethanesulfonimide), LiTFS (lithium trifluoromethanesulfonate), LiDFOB (lithium difluorooxalate borate), LiBOB (lithium bisoxalate borate), LiPO 2 F 2 (lithium difluorophosphate), One or more of LiDFOP (lithium difluorooxalate phosphate) and LiTFOP (lithium tetrafluorooxalate phosphate), such as LiPF 6 (lithium hexafluorophosphate), LiBF 4 (lithium tetrafluoroborate), LiBOB (lithium
- the electrolyte may also optionally contain other additives, such as vinylene carbonate (VC), vinyl ethylene carbonate (VEC), fluoroethylene carbonate (FEC), difluoroethylene carbonate (DFEC), three Fluoromethyl ethylene carbonate (TFPC), succinonitrile (SN), adiponitrile (ADN), glutaronitrile (GLN), hexanetrinitrile (HTN), 1,3-propane sultone (1 ,3-PS), ethylene sulfate (DTD), methylene disulfonate (MMDS), 1-propene-1,3-sultone (PST), 4-methyl ethylene sulfate (PCS), 4-ethyl ethylene sulfate (PES), 4-propyl ethylene sulfate (PEGLST), propylene sulfate (TS), 1,4-butane sultone (1,4- BS), ethylene sulfite (DTO), dimethyl sulfite (
- the lithium ion secondary battery in the embodiments of the present application has no special restrictions on the separator.
- Any well-known separator with a porous structure with electrochemical stability and mechanical stability can be selected, such as glass fiber, non-woven fabric, polyethylene (PE ), polypropylene (PP) and polyvinylidene fluoride (PVDF) one or more of single-layer or multi-layer films.
- PE polyethylene
- PP polypropylene
- PVDF polyvinylidene fluoride
- the positive pole piece and the negative pole piece are alternately stacked, and an isolation film is arranged between the positive pole piece and the negative pole piece for isolation to obtain a battery core, which can also be obtained after winding. Placing the electric core in the casing, injecting electrolyte, and sealing to obtain a lithium ion secondary battery.
- FIG. 4 shows a lithium ion secondary battery 5 with a square structure as an example.
- the secondary battery may include an outer package.
- the outer packaging is used to encapsulate the positive pole piece, the negative pole piece and the electrolyte.
- the outer package may include a housing 51 and a cover 53.
- the housing 51 may include a bottom plate and a side plate connected to the bottom plate, and the bottom plate and the side plate enclose to form an accommodating cavity.
- the housing 51 has an opening communicating with the containing cavity, and a cover plate 53 can cover the opening to close the containing cavity.
- the positive pole piece, the negative pole piece, and the separator may be formed into the cell 52 through a winding process or a lamination process.
- the battery core 52 is encapsulated in the containing cavity.
- the electrolyte can be an electrolyte, and the electrolyte is infiltrated in the cell 52.
- the number of battery cells 52 contained in the lithium ion secondary battery 5 can be one or several, which can be adjusted according to requirements.
- the outer packaging of the lithium ion secondary battery may be a hard case, such as a hard plastic case, an aluminum case, a steel case, or the like.
- the outer packaging of the secondary battery may also be a soft bag, such as a pouch type soft bag.
- the material of the soft bag can be plastic, for example, it can include one or more of polypropylene (PP), polybutylene terephthalate (PBT), polybutylene succinate (PBS), and the like.
- the lithium ion secondary battery can be assembled into a battery module, and the number of lithium ion secondary batteries contained in the battery module can be multiple, and the specific number can be adjusted according to the application and capacity of the battery module.
- Fig. 6 is a battery module 4 as an example.
- a plurality of lithium ion secondary batteries 5 may be arranged in order along the length direction of the battery module 4. Of course, it can also be arranged in any other manner. Furthermore, the plurality of lithium ion secondary batteries 5 can be fixed by fasteners.
- the battery module 4 may further include a housing having an accommodating space, and a plurality of lithium ion secondary batteries 5 are accommodated in the accommodating space.
- the above-mentioned battery modules can also be assembled into a battery pack, and the number of battery modules contained in the battery pack can be adjusted according to the application and capacity of the battery pack.
- FIGS. 7 and 8 show the battery pack 1 as an example.
- the battery pack 1 may include a battery box and a plurality of battery modules 4 provided in the battery box.
- the battery box includes an upper box body 2 and a lower box body 3.
- the upper box body 2 can be covered on the lower box body 3 and forms a closed space for accommodating the battery module 4.
- a plurality of battery modules 4 can be arranged in the battery box in any manner.
- the present application also provides a device, which includes at least one of the lithium ion secondary battery, battery module, or battery pack described in the present application.
- the lithium ion secondary battery, battery module or battery pack can be used as a power source of the device, and can also be used as an energy storage unit of the device.
- the device can be, but is not limited to, mobile devices (e.g., mobile phones, laptop computers, etc.), electric vehicles (e.g., pure electric vehicles, hybrid electric vehicles, plug-in hybrid electric vehicles, electric bicycles, electric scooters, electric golf Vehicles, electric trucks, etc.), electric trains, ships and satellites, energy storage systems, etc.
- the device can choose a lithium ion secondary battery, battery module, or battery pack according to usage requirements.
- Figure 9 is a device as an example.
- the device is a pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle, etc.
- a battery pack or a battery module can be used.
- the device may be a mobile phone, a tablet computer, a notebook computer, and the like.
- the device is generally required to be light and thin, and a lithium ion secondary battery can be used as a power source.
- the doping element is Sb.
- the doping element precursor antimony oxide Sb 2 O 3 is roughly equally divided into 3 batches for Sb doping.
- the positive electrode active material precursor [Ni 0.8 Co 0.1 Mn 0.1 ](OH) 2 , lithium hydroxide LiOH and the first batch of antimony oxide Sb 2 O 3 into the high-speed mixer for mixing for 1 hour to obtain a mixture.
- the molar ratio of the positive electrode active material precursor to lithium hydroxide Li/Me is 1.05
- Me represents the total molar amount of Ni, Co, and Mn in the positive electrode active material precursor.
- the mixture material is put into an atmosphere sintering furnace for sintering, the sintering temperature is 830° C., the sintering time is 5 hours, and the sintering atmosphere is an oxygen-containing atmosphere with an O 2 concentration of 90%.
- the product of the first sintering treatment and the second batch of antimony oxide were added to the high-speed mixer to mix for 1 hour, and the second sintering was carried out.
- the sintering temperature, sintering time and sintering atmosphere were the same as those of the first sintering.
- the product of the second sintering treatment and the third batch of antimony oxide were added to the high-speed mixer for 1h, and the third sintering was carried out.
- the sintering temperature and sintering atmosphere were the same as the previous two sintering, and the sintering time was 10h.
- the total sintering time is 20h.
- the high nickel ternary positive electrode active material can be obtained.
- the amount of antimony oxide added makes the true doping concentration of Sb in the positive electrode active material 25110 ⁇ g/cm 3 .
- SBR binder styrene butadiene rubber
- CMC-Na thickener sodium carboxymethyl cellulose
- PE Polyethylene
- Example 5 The difference from Example 1 is that the relevant parameters in the preparation steps of the positive electrode active material are changed, and the type of doping elements when mixed, the content of each batch, the sintering temperature are 600 °C ⁇ 900 °C, and the sintering atmosphere is O 2 concentration: 75%-95% oxygen-containing atmosphere, total sintering time 10h-20h, to obtain a positive electrode active material with predetermined doping element type, doping amount and doping uniformity, which involves multi-element doping in Example 4 and implementation
- the content of each doping element is basically the same, and no doping element is added in Comparative Example 1; the other parameters are shown in Table 1 and Table 2.
- Example 2 The difference from Example 1 is that the doping elements in Example 12 are added in a single batch, and the sintering temperature is 720°C; the doping elements in Comparative Example 5 are added in a single batch, and the sintering temperature is 650°C; other parameters are shown in Table 1 and Tables. 2.
- Example 18 The difference from Example 1 is that in Example 18, the temperature of the first sintering is 800°C and the sintering is 7h; the temperature of the second sintering is 750°C and the sintering is 2h; the temperature of the third sintering is 700°C, and the sintering 2h; Among them, the second batch of doping elements account for 40% of the total doping element content, and the third batch of doping elements account for 10% of the total doping element content; other parameters are shown in Table 1 and Table 2.
- Example 19 The difference from Example 1 is that in Example 19, the first sintering temperature is 750°C, sintering 6h; the second sintering temperature is 700°C, sintering 1h; the third sintering temperature is 650°C, sintering 1h; Among them, the second batch of doping elements account for 50% of the total doping element content, and the third batch of doping elements account for 20% of the total doping element content; other parameters are shown in Table 1 and Table 2.
- Example 1 The difference from Example 1 is that the positive electrode active material precursors of Examples 20 and 21 and Comparative Example 7 are [Ni 0.6 Co 0.2 Mn 0.2 ](OH) 2 , and there are differences in the types of dopant elements mixed in; Comparative Example 6
- the precursor of the positive electrode active material is [Ni 0.6 Co 0.2 Mn 0.2 ](OH) 2 , with no doping elements added; other parameters are shown in Table 1 and Table 2.
- charge 18 button batteries with a constant current of 1C to the upper limit of the charge-discharge cut-off voltage, then charge at a constant voltage to a current of ⁇ 0.05mA, then leave it aside for 2 minutes, and then discharge at a constant current of 1C to the charge-discharge cut-off voltage Lower limit.
- the 18 button batteries after the above charge and discharge were charged to 2.8V, 2.9V, 3.0V, 3.1V, 3.2V, 3.3V,...4.0V, 4.1V, 4.2V, at a rate of 0.1C, respectively.
- 4.3V, 4.4V, 4.5V that is, the charging voltage interval is 0.1V).
- the button cell is charged to the voltage corresponding to the "78% de-lithium state" at a rate of 0.1C. Then disassemble the button cell in the drying room, take out the entire positive pole piece and put it in a beaker, pour an appropriate amount of high-purity anhydrous dimethyl carbonate (DMC), replace the DMC every 8h, wash it 3 times in a row, and then put it Put it into the vacuum standing box of the drying room, keep the vacuum state at -0.096MPa, and dry for 12 hours; scrape the dried positive pole piece with a blade in the drying room, and weigh 4.95mg ⁇ 5.05mg of the positive electrode active material powder Put the high-pressure crucible of the STA449F3-QMS403C differential scanning calorimeter into the seal, heat the sample at a heating rate of 10°C/min, record the data of the sample's heat flow change with temperature, get the DSC spectrum, and get the main exothermic peak The exothermic onset temperature, half-width, integral area
- the positive electrode in the button battery can also be a positive electrode piece that is disassembled in a drying room directly from the whole battery, and the middle area is selected to punch out an appropriate size as the positive electrode piece of the button battery.
- the test method for the mass concentration of doping elements at the 17 sites is as follows: the detection elements are Li, O, Ni, Co, Mn and doping elements, and the SEM parameters are set to 20kV acceleration voltage, 60 ⁇ m aperture, 8.5mm working distance, 2.335A current, when performing EDS test, it is necessary to stop the test when the spectrum area reaches more than 250,000 cts (controlled by acquisition time and acquisition rate), and collect data to obtain the mass concentration of doping elements at each point, which are recorded as ⁇ 1 , ⁇ 2 , ⁇ 3 , ..., ⁇ 17 .
- Average mass concentration of doped elements in positive electrode active material particles Measurement method the above-mentioned EDS-SEM testing method is adopted, as shown by the dashed frame in FIG. 3, the testing area covers all the points scanned by the positive electrode active material particles, and does not exceed the cross section of the secondary particles.
- the true density ⁇ true of the positive electrode active material is measured by the TD2400 powder true density tester of Beijing Biood Electronic Technology Co., Ltd.
- n is the molar mass of gas in the sample cup
- R is the ideal gas constant, which is 8.314
- T is the ambient temperature, which is 298.15K.
- the 7000DV inductively coupled plasma-Optical Emission spectrometers (ICP-OES) of Platinum Elmer (PE) was used to test the mass concentration of doped elements in the positive electrode active material.
- the test method is as follows: take the pole piece containing the positive electrode active material and punch it into a round piece with a total mass greater than 0.5g or take at least 5g of the positive electrode active material powder sample, weigh and record the mass of the sample, put it into the digestion tank, and slowly add 10mL of aqua regia As a digestion reagent, it is then placed in the Mars5 microwave digestion instrument of CEM Corporation in the United States, and digested at a microwave emission frequency of 2450Hz; the digested sample solution is transferred to a volumetric flask and shaken, and the sample is placed in the ICP-OES sampling system. 0.6MPa argon pressure and 1300W radio frequency power were used to test the mass concentration of doping elements of the positive electrode active material.
- the true doping concentration ⁇ of the positive electrode active material is calculated according to the aforementioned formula (2).
- the charge-discharge cut-off voltage of the button cell is 2.8V-4.35V
- the charge-discharge cut-off voltage of the full battery is 2.8V-4.3V.
- the doping mass ratio of each batch the mass of the first batch of doping element precursors: the mass of the second batch of doping element precursors: the mass of the third batch of doping element precursors.
- the valence shown in Table 2 is the highest valence of the doping element in the "78% delithiation state" positive electrode active material.
- the positive electrode active material include layered lithium nickel cobalt manganese oxide
- the molar content of nickel in the lithium nickel cobalt manganese oxide accounts for 60% to 90% of the total molar content of nickel, cobalt and manganese
- the transition metal layer includes doping elements
- the particles of the positive electrode active material are partially doped
- the relative deviation of the mass concentration is 20% or less
- the DSC spectrum of the positive electrode active material in the "78% delithiation state” the onset exothermic temperature of the main exothermic peak is above 200°C, and the integral area of the main exothermic peak Below 100J/g
- the lithium ion secondary battery can have both higher capacity and higher high temperature cycle performance.
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Abstract
Description
Claims (20)
- 根据权利要求1所述的正极活性材料,其中,所述主放热峰的半峰宽为30℃以下;或,所述主放热峰的峰值温度为230℃以上。
- 根据权利要求1或2所述的正极活性材料,其中,所述正极活性材料的颗粒中所述掺杂元素的局部质量浓度的相对偏差为15%以下。
- 根据权利要求1-3任一项所述的正极活性材料,其中,所述正极活性材料在78%脱锂态时,所述掺杂元素具有+3价以上的化合价,可选的具有+4价、+5价、+6价、+7价及+8价中的一种或多种化合价。
- 根据权利要求1-4任一项所述的正极活性材料,其中,所述掺杂元素包括Al、Si、Ti、V、Ge、Se、Zr、Nb、Ru、Pd、Sb、Te及W中的一种或多种;可选的,掺杂元素可包括Al、Si、Ge、Se、Zr、Ru、Sb、Te及W中的一种或多种;可选的,掺杂元素可包括Si、Ge、Se、Ru、Sb、Te及W中的一种或多种。
- 根据权利要求1-5任一项所述的正极活性材料,其中,所述正极活性材料的真密度ρ 真满足:4.6g/cm 3≤ρ 真≤4.9g/cm 3。
- 根据权利要求1-6任一项所述的正极活性材料,其中,所述正极活性材料的真实掺杂浓度ω满足:2300μg/cm 3≤ω≤49500μg/cm 3;可选的,3000μg/cm 3≤ω≤35000μg/cm 3;可选的,14810μg/cm 3≤ω≤36710μg/cm 3。
- 根据权利要求1-7任一项所述的正极活性材料,其中,所述正极活性材料中所述掺杂元素的质量浓度相对于所述正极活性材料的颗粒中所述掺杂元素的平均质量浓度的偏差ε<50%;可选的,ε≤30%;进一步可选的,ε≤20%。
- 根据权利要求1-8任一项所述的正极活性材料,其中,所述正极活性材料还满足 如下(1)~(4)中的一个或多个:(1)所述正极活性材料的体积平均粒径D v50为5μm~20μm,可选的为8μm~15μm,进一步可选的为9μm~11μm;(2)所述正极活性材料的比表面积为0.2m 2/g~1.5m 2/g,可选的为0.3m 2/g~1m 2/g;(3)所述正极活性材料的振实密度为2.3g/cm 3~2.8g/cm 3;(4)所述正极活性材料在5吨(相当于49kN)压力下的压实密度为3.1g/cm 3~3.8g/cm 3。
- 根据权利要求1-9任一项所述的正极活性材料,其中,所述锂镍钴锰氧化物满足化学式Li 1+a[Ni xCo yMn zM b]O 2,其中,M为所述掺杂元素,M选自Al、Si、Ti、V、Ge、Se、Zr、Nb、Ru、Pd、Sb、Te及W中的一种或多种,0.7≤x≤0.9,0<y<0.3,0<z<0.3,0≤a<0.2,0<b<0.3,x+y+z+b=1;或,所述锂镍钴锰氧化物满足化学式Li 1+c[Ni r-dCo sMn tM’ d]O 2,其中,M’为所述掺杂元素,M’选自Al、Si、Ti、V、Ge、Se、Zr、Nb、Ru、Pd、Sb、Te及W中的一种或多种,0.7≤r-d≤0.9,0<s<0.3,0<t<0.3,0≤c<0.2,0<d<0.3,r+s+t=1。
- 一种正极活性材料的制备方法,包括以下步骤:将正极活性材料前驱体、锂源和掺杂元素前驱体混合,得到混合料,其中所述正极活性材料前驱体选自含有Ni、Co和Mn的氧化物、氢氧化物及碳酸盐中的一种或多种,且镍的摩尔含量占镍、钴及锰的总摩尔含量的60%~90%;对所述混合料进行烧结处理,得到正极活性材料;所述锂镍钴锰氧化物的过渡金属层包括掺杂元素,且所述正极活性材料的颗粒中所述掺杂元素的局部质量浓度的相对偏差为20%以下;以及,所述正极活性材料在78%脱锂态时的差示扫描量热分析谱图中,主放热峰的起始放热温度为200℃以上,主放热峰的积分面积为100J/g以下。
- 根据权利要求11所述的方法,其中,所述掺杂元素前驱体选自铝氧化物、硅氧化物、钛氧化物、钒氧化物、锗氧化物、硒氧化物、锆氧化物、铌氧化物、钌氧化物、钯氧化物、锑氧化物、碲氧化物和钨氧化物中的一种或多种;可选的,所述掺杂元素前驱体选自Al 2O 3、SiO 2、SiO、TiO 2、TiO、V 2O 5、V 2O 4、V 2O 3、GeO 2、SeO 2、ZrO 2、Nb 2O 5、NbO 2、RuO 2、PdO、Sb 2O 5、Sb 2O 3、TeO 2、WO 2、和WO 3中的一种或多种。
- 根据权利要求11或12所述的方法,其中,所述烧结处理满足如下(a)~(c)中的至少一项:(a)烧结处理的气氛为含氧气氛;可选的,烧结气氛的氧气浓度为70%~100%,可选的为75%~95%;(b)烧结处理的温度为600℃~1000℃,可选的为700℃~900℃;(c)烧结处理的时间为5h~25h,可选的为10h~20h。
- 根据权利要求11-13任一项所述的方法,其中,将所述掺杂元素前驱体等分为L份或任意分为L份,分为L个批次进行掺杂,其中L为1~5,可选的为2~3;可选的包括:将正极活性材料前驱体、锂源及第1批次掺杂元素前驱体混合,并进行第1次烧结处理;将第1次烧结处理的产物与第2批次掺杂元素前驱体进行混合,并进行第2次烧结处理;以此类推,直至将第L-1次烧结处理的产物与第L批次掺杂元素前驱体进行混合,并进行第L次烧结处理,得到正极活性材料。
- 根据权利要求14所述的方法,其中,所述方法满足如下(a)~(c)中的至少一项:(a)每次烧结处理的温度为600℃~1000℃,可选的为700℃~900℃,还可选的为800℃~850℃;(b)每次烧结处理的时间为3h~25h,可选的为5h~10h;(c)总的烧结处理时间为5h~25h,可选的为15h~25h。
- 一种正极极片,包括正极集流体以及设置于所述正极集流体上的正极活性物质层,所述正极活性物质层包括根据权利要求1-10任一项所述的正极活性材料、或根据权利要求11-15任一项所述的制备方法得到的正极活性材料。
- 一种锂离子二次电池,包括根据权利要求16所述的正极极片。
- 一种电池模块,包括根据权利要求17所述的锂离子二次电池。
- 一种电池包,包括根据权利要求17所述的锂离子二次电池、或根据权利要求18所述的电池模块。
- 一种装置,包括根据权利要求17所述的锂离子二次电池、根据权利要求18所述的电池模块、或根据权利要求19所述的电池包中的至少一种。
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JP2022513042A JP7223207B2 (ja) | 2019-09-02 | 2020-08-19 | 正極活性材料、その調製方法、正極シート、リチウムイオン二次電池及びその関連の電池モジュール、電池パック並びに装置 |
KR1020227008655A KR20220049021A (ko) | 2019-09-02 | 2020-08-19 | 정극 활성 재료, 그 제조 방법, 정극 시트, 리튬 이온 이차 전지 및 그 관련 전지 모듈, 전지 팩과 장치 |
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CN117276534A (zh) * | 2023-11-21 | 2023-12-22 | 宜宾光原锂电材料有限公司 | 高循环正极材料前驱体及其制备方法与正极材料和电池 |
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---|---|---|---|---|
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Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2011108652A1 (ja) * | 2010-03-04 | 2011-09-09 | Jx日鉱日石金属株式会社 | リチウムイオン電池用正極活物質、リチウムイオン電池用正極、及び、リチウムイオン電池 |
CN107394193A (zh) * | 2017-06-30 | 2017-11-24 | 湖南金富力新能源股份有限公司 | 锂离子电池正极材料及其制法和应用 |
CN109665570A (zh) * | 2018-12-03 | 2019-04-23 | 林奈(中国)新能源有限公司 | 一种掺杂改性的高镍四元正极材料、制备方法及用途 |
CN109713252A (zh) * | 2018-11-30 | 2019-05-03 | 高点(深圳)科技有限公司 | 电性能一致性高的高镍三元正极材料及其制备方法和应用 |
CN109904432A (zh) * | 2019-03-15 | 2019-06-18 | 北京理工大学 | 一种w掺杂改性的高镍三元正极材料 |
CN110034297A (zh) * | 2019-03-28 | 2019-07-19 | 欣旺达电动汽车电池有限公司 | 一种高镍锂离子正极材料及其制备方法 |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR102314045B1 (ko) * | 2014-12-18 | 2021-10-18 | 삼성에스디아이 주식회사 | 복합 양극 활물질, 그 제조방법, 이를 포함한 양극 및 리튬 전지 |
CN110235291A (zh) | 2017-10-11 | 2019-09-13 | 株式会社Lg化学 | 正极活性材料、其制备方法以及包含其的锂二次电池 |
CN108269981A (zh) * | 2018-01-03 | 2018-07-10 | 中航锂电(洛阳)有限公司 | 一种镍钴锰酸锂复合正极材料及其制备方法、锂电池 |
CN109004175B (zh) * | 2018-02-26 | 2020-09-18 | 宁德新能源科技有限公司 | 正极极片和锂离子电池 |
CN109437339A (zh) * | 2018-12-03 | 2019-03-08 | 林奈(中国)新能源有限公司 | 高镍四元正极材料前驱体及高镍四元正极材料、制备方法和用途 |
-
2019
- 2019-09-02 CN CN201910824127.8A patent/CN112447964B/zh active Active
-
2020
- 2020-08-19 EP EP20861329.9A patent/EP3951949A4/en active Pending
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-
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- 2023-02-15 US US18/109,866 patent/US11760657B2/en active Active
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2011108652A1 (ja) * | 2010-03-04 | 2011-09-09 | Jx日鉱日石金属株式会社 | リチウムイオン電池用正極活物質、リチウムイオン電池用正極、及び、リチウムイオン電池 |
CN107394193A (zh) * | 2017-06-30 | 2017-11-24 | 湖南金富力新能源股份有限公司 | 锂离子电池正极材料及其制法和应用 |
CN109713252A (zh) * | 2018-11-30 | 2019-05-03 | 高点(深圳)科技有限公司 | 电性能一致性高的高镍三元正极材料及其制备方法和应用 |
CN109665570A (zh) * | 2018-12-03 | 2019-04-23 | 林奈(中国)新能源有限公司 | 一种掺杂改性的高镍四元正极材料、制备方法及用途 |
CN109904432A (zh) * | 2019-03-15 | 2019-06-18 | 北京理工大学 | 一种w掺杂改性的高镍三元正极材料 |
CN110034297A (zh) * | 2019-03-28 | 2019-07-19 | 欣旺达电动汽车电池有限公司 | 一种高镍锂离子正极材料及其制备方法 |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN114497447A (zh) * | 2022-01-25 | 2022-05-13 | 珠海冠宇电池股份有限公司 | 一种正极片和锂离子电池 |
CN117276534A (zh) * | 2023-11-21 | 2023-12-22 | 宜宾光原锂电材料有限公司 | 高循环正极材料前驱体及其制备方法与正极材料和电池 |
CN117276534B (zh) * | 2023-11-21 | 2024-02-13 | 宜宾光原锂电材料有限公司 | 高循环正极材料前驱体及其制备方法与正极材料和电池 |
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JP7223207B2 (ja) | 2023-02-15 |
US20230202864A1 (en) | 2023-06-29 |
US20220185696A1 (en) | 2022-06-16 |
EP3951949A1 (en) | 2022-02-09 |
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