CN113224278A - Modified lithium ferric manganese phosphate material, preparation method and application thereof - Google Patents
Modified lithium ferric manganese phosphate material, preparation method and application thereof Download PDFInfo
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Abstract
The invention provides a modified lithium ferric manganese phosphate material, a preparation method and application thereof. The modified lithium ferric manganese phosphate material comprises a magnesium-doped lithium ferric manganese phosphate nuclear layer and a boron-containing coating layer coated on the surface of the magnesium-doped lithium ferric manganese phosphate nuclear layer. The modified lithium ferric manganese phosphate material comprises a magnesium-doped lithium ferric manganese phosphate nuclear layer and a boron-containing coating layer coated on the surface of the magnesium-doped lithium ferric manganese phosphate nuclear layer. Based on the structure, the material has higher conductivity and lithium ion diffusion capacity, lower charge transfer resistance and better stability. When the lithium ion battery positive electrode material is used as a lithium ion battery positive electrode material, the rate capability of the battery is better, the first charge-discharge efficiency and the first capacity are higher, the cycle performance is better, and particularly the cycle life is longer.
Description
Technical Field
The invention relates to the field of lithium ion batteries, in particular to a modified lithium ferric manganese phosphate material, and a preparation method and application thereof.
Background
The positive electrode material with high specific capacity is one of the key factors for limiting the wide application of lithium ion battery, and among numerous positive electrode materials, LiFe1-xMnxPO4Has LiMnPO function4Relatively high voltage and LiFePO4The advantage of structural stability. However, LiFexMn1-xPO4FeO in the medium6And MnO with MnO6Octahedron through PO4The tetrahedral connection does not form a continuous conductive network, making the material relatively poor in conductivity. Simultaneously, MnPO4With FePO4The structural difference causes the thermal stability of the material to be poor.
However, although researchers have conducted a great deal of research on the synthesis and modification methods, LiFe1-xMnxPO4The cathode material still has low electronic conductivity and lithium ion diffusion rate, and uses LiFe1-xMnxPO4The lithium ion battery composed of the anode material has poor cycle performance, rate capability and power characteristic. Therefore, there is a need for a modified lithium ferric manganese phosphate material having high electronic conductivity and high lithium ion diffusion coefficient, and a lithium ion battery comprising the modified lithium ferric manganese phosphate material has good cycle performance and rate capability.
Disclosure of Invention
The invention mainly aims to provide a modified lithium iron manganese phosphate material, a preparation method and application thereof, and aims to solve the problems that in the prior art, the lithium iron manganese phosphate material is low in electronic conductivity and lithium ion diffusion rate, and a lithium ion battery formed by the material is poor in cycle performance and rate performance.
In order to achieve the above object, according to one aspect of the present invention, there is provided a modified lithium ferric manganese phosphate material, which includes a magnesium-doped lithium ferric manganese phosphate core layer and a boron-containing cladding layer coated on a surface of the magnesium-doped lithium ferric manganese phosphate core layer.
Further, magnesium doped iron phosphateThe material of the manganese lithium nuclear layer is Li (Fe)yMn1-y)1-xMgxPO4，x＝0.01～0.05，y＝0.57～0.62。
Further, the material of the boron-containing clad layer is boron oxide.
Furthermore, the particle size D50 of the magnesium-doped lithium ferric manganese phosphate core layer is 5-20 μm, and the thickness of the boron-containing coating layer is 1-20 nm.
According to another aspect of the present invention, a preparation method of the modified lithium ferric manganese phosphate material is provided, which includes the following steps: mixing a manganese source, a phosphorus source, an iron source, a lithium source, a magnesium source and water to form an intermediate reaction solution; drying and pre-calcining the intermediate reaction solution in sequence to obtain a nuclear layer precursor; and mixing the nuclear layer precursor with a boron source, and then roasting to obtain the modified lithium ferric manganese phosphate material.
Further, the boron source is boric acid and/or boron nitrate; preferably, the boron source accounts for 30-60 wt% of the total weight of the boron source and the core layer precursor, and preferably 45-60 wt%; the magnesium source is Mg (CH)3COO)2And/or Mg (OH)2(ii) a Preferably, the molar ratio of the manganese source to the phosphorus source to the iron source to the lithium source to the magnesium source is (0.38-0.44): 1, (0.57-0.62): 1.05, (0.01-0.05); preferably, the lithium source is CH3COOLi·2H2O and/or LiOH; the manganese source is Mn (CH)3COO)2·4H2O and/or MnSO4(ii) a The phosphorus source is NH4H2PO4(ii) a The iron source being FeCl2·4H2O and/or Fe (CH)3COO)2。
Further, in the pre-calcination treatment process, the treatment temperature is 300-450 ℃, and the treatment time is 5-8 hours; in the roasting treatment process, the treatment temperature is 650-850 ℃, and the treatment time is 6-24 h.
Further, before roasting the nuclear layer precursor and the boron source, grinding the nuclear layer precursor; preferably, the grinding treatment process comprises the roller crushing treatment and the ultracentrifugal grinding and crushing treatment which are sequentially carried out; preferably, the particle size of the precursor of the core layer is 5-20 μm.
According to still another aspect of the present invention, a cathode material is provided, which is the above modified lithium manganese iron phosphate material, or the modified lithium manganese iron phosphate material prepared by the above preparation method.
According to another aspect of the present invention, a lithium ion battery is provided, which includes a positive electrode, where the positive electrode includes a positive electrode current collector and a positive electrode active layer located on a surface of the positive electrode current collector, and the positive electrode active layer includes a positive electrode material, a conductive agent and a binder, where the positive electrode material is the above modified lithium manganese iron phosphate material, or is the modified lithium manganese iron phosphate material prepared by the above preparation method.
The modified lithium ferric manganese phosphate material comprises a magnesium-doped lithium ferric manganese phosphate nuclear layer and a boron-containing coating layer coated on the surface of the magnesium-doped lithium ferric manganese phosphate nuclear layer. Based on the structure, the material has higher conductivity and lithium ion diffusion capacity, lower charge transfer resistance and better stability. When the lithium ion battery positive electrode material is used as a lithium ion battery positive electrode material, the rate capability of the battery is better, the first charge-discharge efficiency and the first capacity are higher, the cycle performance is better, and particularly the cycle life is longer.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:
fig. 1 shows a graph comparing cycle performance of assembled batteries of examples of the present invention and comparative examples.
Detailed Description
It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.
As described in the background art, the lithium iron manganese phosphate material in the prior art has the problems of low electronic conductivity and lithium ion diffusion rate, and poor cycle performance and rate performance of the lithium ion battery formed by the material. In order to solve the problem, the invention provides a modified lithium ferric manganese phosphate material which comprises a magnesium-doped lithium ferric manganese phosphate nuclear layer and a boron-containing coating layer coated on the surface of the magnesium-doped lithium ferric manganese phosphate nuclear layer.
Magnesium atoms can replace partial atoms in the lithium manganese iron phosphate in situ in a lattice replacement mode, so that a magnesium-doped lithium manganese iron phosphate nuclear layer is formed. In the core layer, Mg2+It does not directly participate in the charge and discharge process, so that it can play the role of a strut in the nuclear layer, thereby enhancing the structural stability of the material. Correspondingly, when the material is subsequently used as the lithium battery anode material, the stability of the battery in the charging and discharging process can be improved, and the cycle life of the battery is further prolonged. And the doped Mg2+ can enter the crystal lattice of the lithium manganese iron phosphate to occupy the position of part of Li or Fe2+, so that the crystal structure of the material is changed, and the conductivity of the material is improved. Furthermore, the surface of the core layer of the magnesium-doped lithium iron manganese phosphate is coated with a boron-containing coating layer, the boron-containing coating layer can reduce the charge transfer impedance of the material, and Li < + > can pass through an electrode interface more quickly, so that the rate capability of the battery can be effectively improved. In addition, the boron-containing coating layer can also improve the first charge-discharge efficiency and capacity of the battery and improve the cycle performance of the battery.
In a word, the modified lithium ferric manganese phosphate material comprises a magnesium-doped lithium ferric manganese phosphate nuclear layer and a boron-containing coating layer coated on the surface of the magnesium-doped lithium ferric manganese phosphate nuclear layer. Based on the structure, the material has higher conductivity and lithium ion diffusion capacity, lower charge transfer resistance and better stability. When the lithium ion battery positive electrode material is used as a lithium ion battery positive electrode material, the rate capability of the battery is better, the first charge-discharge efficiency and the first capacity are higher, the cycle performance is better, and particularly the cycle life is longer.
In order to further improve various performances of the modified lithium ferric manganese phosphate material and fully exert the advantages brought by the core layer and the cladding layer structure, in a preferred embodiment, the material of the magnesium-doped lithium ferric manganese phosphate core layer is Li (Fe)yMn1-y)1- xMgxPO4，x＝0.01～0.05，y＝0.57～0.62。
Preferably, the material of the boron-containing cladding layer is boron oxide. Based on the boron-containing coating layer, the charge transfer resistance of the material can be further reduced, and the rate performance of the battery is further effectively improved. Meanwhile, the first charge-discharge efficiency and capacity of the battery are higher, and the cycle performance is better.
Preferably, the particle size D50 of the magnesium-doped lithium ferric manganese phosphate core layer is 5-20 μm, and the thickness of the boron-containing coating layer is 0.2-2 nm. Within the range, the performances of the core layer and the coating layer can be well balanced, meanwhile, the core layer and the coating layer have better synergistic effect, and the conductivity and the lithium ion diffusion capacity of the material are higher.
According to another aspect of the present invention, the present invention also provides a preparation method of the modified lithium ferric manganese phosphate material, which comprises the following steps: mixing a manganese source, a phosphorus source, an iron source, a lithium source, a magnesium source and water to form an intermediate reaction solution; drying and pre-calcining the intermediate reaction solution in sequence to obtain a nuclear layer precursor; and mixing the nuclear layer precursor with a boron source, and then roasting to obtain the modified lithium ferric manganese phosphate material.
In the preparation method, the manganese source, the phosphorus source, the iron source, the lithium source, the magnesium source and water are mixed to form the intermediate reaction liquid, so that the magnesium source and the lithium manganese iron phosphate main component can be mixed firstly, the dispersion uniformity of the magnesium source is promoted to be better, and further, in the subsequent pre-calcination treatment process, magnesium atoms can replace partial atoms in the lithium manganese iron phosphate in situ in a lattice replacement mode more efficiently, and a nuclear layer precursor with better stability is formed. And then mixing the nuclear layer precursor and a boron source, and then roasting to promote the surface of the nuclear layer of the magnesium-doped lithium manganese iron phosphate to be more stably and completely coated to obtain the boron-containing coating layer. Based on the operation, the boron-containing coating layer and the magnesium-doped lithium ferric manganese phosphate nuclear layer have better synergistic effect, the material has higher conductivity and lithium ion diffusion capacity, lower charge transfer resistance and better stability. When the lithium ion battery positive electrode material is used as a lithium ion battery positive electrode material, the rate capability of the battery is better, the first charge-discharge efficiency and the first capacity are higher, the cycle performance is better, and particularly the cycle life is longer.
In a preferred embodiment, a manganese source, a carbon source, a phosphorus source, an iron source, a lithium source and a magnesium source are mixed and dissolved in water, the mixture is placed in a water bath at 50-80 ℃ and continuously mechanically stirred for 4-6 hours to obtain an intermediate reaction liquid, and the intermediate reaction liquid is dried in a vacuum drying oven at 105 ℃ for 24 hours and then ground into powder.
Preferably, the boron source is boric acid and/or boron nitrate. Based on the above, in the roasting treatment process, boric acid and boron nitrate are subjected to thermal decomposition on the surface of the doped lithium manganese iron phosphate core layer, so that a uniform and dense boron oxide layer is formed on the surface of the core layer, and a boron-containing coating layer is formed. This can reduce the charge transfer resistance of the material, and can effectively improve the rate performance of the battery. In addition, the boron oxide coating layer can also improve the first charge-discharge efficiency and capacity of the battery and improve the cycle performance of the battery. More preferably, the weight ratio of the boron source to the core layer precursor is 30 to 60 wt%, preferably 45 to 60 wt%. After roasting, the boron-containing coating layer with relatively uniform thickness can be coated on the surface of the magnesium-doped lithium iron manganese phosphate nuclear layer, and the promotion effect on the overall performance of the material is better.
In order to fully utilize the advantages of the core layer structure, the weight ratio of the manganese source, the phosphorus source, the iron source, the lithium source and the magnesium source is preferably (0.38-0.44): 1, (0.57-0.62): 1.05, (0.01-0.05). Within the range, the conductivity of the material is higher, and when the material is used as a lithium ion battery cathode material, the cycle performance of the battery is better.
Preferably, in the pre-calcination treatment process, the treatment temperature is 300-450 ℃, and the treatment time is 5-8 h. Thus, Mg in the magnesium source2+Partial atoms in the lithium ferric manganese phosphate can be replaced in situ in a crystal lattice replacement mode more smoothly, and the electronic structure of the nuclear layer is promoted to be more stable. Correspondingly, when the material is subsequently used as the lithium battery anode material, the stability of the battery in the charging and discharging process can be further improved, and the cycle life of the battery is further prolonged.
In order to further improve the performance stability of the boron-containing coating layer, the preferable treatment temperature is 650-850 ℃ and the treatment time is 6-24 h in the roasting treatment process.
For the purpose of further improving reaction stability and improving comprehensive performance of the cathode material, the lithium source is CH3COOLi·2H2O and/or LiOH; the manganese source is Mn(CH3COO)2·4H2O and/or MnSO4(ii) a The phosphorus source is NH4H2PO4(ii) a The iron source being FeCl2·4H2O and/or Fe (CH)3COO)2。
Preferably, before the roasting treatment of the nuclear layer precursor and the boron source, the method further comprises the step of grinding the nuclear layer precursor; preferably, the grinding treatment process comprises the roller crushing treatment and the ultracentrifugal grinding and crushing treatment which are sequentially carried out; preferably, the particle size of the precursor of the core layer is 5-20 μm. Therefore, the integrity and compactness of the boron coating layer are better, the charge transfer resistance of the material can be further reduced, and the rate capability of the battery is effectively improved. Meanwhile, the first charge-discharge efficiency and capacity of the battery can be further improved, and the cycle performance of the battery is improved.
According to another aspect of the invention, the invention also provides a positive electrode material, which is the modified lithium ferric manganese phosphate material, or the modified lithium ferric manganese phosphate material prepared by the preparation method.
Based on the reasons, the modified lithium ferric manganese phosphate material comprises a magnesium-doped lithium ferric manganese phosphate core layer and a boron-containing coating layer coated on the surface of the magnesium-doped lithium ferric manganese phosphate core layer. Based on the structure, the material has higher conductivity and lithium ion diffusion capacity, lower charge transfer resistance and better stability. When the lithium ion battery positive electrode material is used as a lithium ion battery positive electrode material, the rate capability and the power characteristic of the battery are better, the first charge-discharge efficiency and the first capacity are higher, the cycle performance is better, and particularly the cycle life is longer.
According to another aspect of the present invention, the present invention further provides a lithium ion battery, including a positive electrode, where the positive electrode includes a positive electrode current collector and a positive electrode active layer located on a surface of the positive electrode current collector, the positive electrode active layer includes a positive electrode material, a conductive agent and a binder, and the positive electrode material is the modified lithium manganese iron phosphate material described above, or is the modified lithium manganese iron phosphate material prepared by the preparation method described above.
Based on the reasons, the lithium ion battery has better rate performance, higher first charge-discharge efficiency and capacity, better cycle performance and longer cycle life in particular.
In a preferred embodiment, the positive electrode is obtained by applying a positive electrode slurry containing the modified lithium ferric manganese phosphate material or the modified lithium ferric manganese phosphate material prepared by the preparation method on a positive electrode current collector and drying the positive electrode slurry; preferably, the positive electrode slurry further includes conductive carbon black, carbon nanotubes, and polyvinylidene fluoride (PVDF); preferably, the negative electrode of the lithium ion battery is a lithium sheet.
The present application is described in further detail below with reference to specific examples, which should not be construed as limiting the scope of the invention as claimed.
Example 1
1. Mixing Mn (CH)3COO)2·4H2O、NH4H2PO4、Fe(CH3COO)2、CH3COOLi·2H2O、Mg(OH)2Uniformly mixing the components according to a molar ratio of 0.44:1:0.58:1.05:0.03, dissolving the mixture in 300mL of deionized water, uniformly stirring the mixture by using a stirring paddle, and then placing the mixture in a water bath at 65 ℃ for stirring for 6 hours to obtain an intermediate reaction solution.
2. Drying the obtained intermediate reaction liquid in a 105 ℃ vacuum drying oven for 24 hours, sequentially carrying out double-roll crushing and ultracentrifugal grinding and crushing treatment on the intermediate reaction liquid, then placing the intermediate reaction liquid in a nitrogen protective atmosphere, pre-calcining the intermediate reaction liquid in a 400 ℃ tubular furnace for 6 hours at the heating rate of 2 ℃/min to obtain a nuclear layer precursor;
3. taking 10g of the core layer precursor, sequentially carrying out double-roll crushing and ultracentrifugal grinding crushing treatment on the core layer precursor, wherein D50 of the core layer precursor is 8 microns, mixing the core layer precursor with 8.2g of boric acid (the boric acid is 45 percent of the total weight of the boric acid and the core layer precursor), heating to 700 ℃ in a nitrogen atmosphere at the heating rate of 2 ℃/min, and roasting for 12 hours to obtain the modified lithium manganese iron phosphate material, wherein the lithium manganese iron phosphate core layer is Li (Fe)0.57Mn0.43)0.971Mg0.029PO4The coating layer is a boron oxide layer.
Wherein the particle size of the magnesium-doped lithium ferric manganese phosphate nuclear layer is 8 mu m, and the average thickness of the boron-containing coating layer is 5 nm.
Example 2
The difference from example 1 is that:
Mn(CH3COO)2·4H2O、NH4H2PO4、Fe(CH3COO)2、CH3COOLi·2H2O、Mg(OH)2boric acid was mixed at 0.43:1:0.59:1.05:0.01, accounting for 60% of the total weight of boric acid and core layer precursor. In the pre-calcination treatment process, the treatment temperature is 350 ℃, and the treatment time is 8 hours; in the roasting treatment process, the treatment temperature is 750 ℃, and the treatment time is 10 hours. The lithium manganese iron phosphate nuclear layer of the obtained modified lithium manganese iron phosphate material is Li (Fe)0.57Mn0.43)0.99Mg0.01PO4The coating layer is a boron oxide layer.
Wherein the particle size of the magnesium-doped lithium ferric manganese phosphate nuclear layer is 6 mu m, and the average thickness of the boron-containing coating layer is 8 nm.
Example 3
The difference from example 1 is that:
Mn(CH3COO)2·4H2O、NH4H2PO4、Fe(CH3COO)2、CH3COOLi·2H2O、Mg(OH)2mixing at a ratio of 0.40:1:0.6:1.05:0.05, boric acid being 40% of the total weight of boric acid and core layer precursor. The water bath temperature is 80 ℃; in the pre-calcination treatment process, the treatment temperature is 300 ℃, and the treatment time is 5 hours; in the roasting treatment process, the treatment temperature is 850 ℃ and the treatment time is 8 h. The lithium manganese iron phosphate nuclear layer of the obtained modified lithium manganese iron phosphate material is Li (Fe)0.6Mn0.4)0.952Mg0.048PO4The coating layer is a boron oxide layer.
Wherein the grain diameter of the magnesium-doped lithium ferric manganese phosphate nuclear layer is 10 mu m, and the thickness of the boron-containing coating layer is 3 nm.
Example 4
The difference from example 1 is that:
Mn(CH3COO)2·4H2O、NH4H2PO4、Fe(CH3COO)2、CH3COOLi·2H2O、Mg(OH)2boric acid was mixed at 0.38:1:0.62:1.05:0.05, accounting for 30% of the total weight of boric acid and core layer precursor. The lithium manganese iron phosphate nuclear layer of the obtained modified lithium manganese iron phosphate material is Li (Fe)0.62Mn0.38)0.95Mg0.05PO4The coating layer is a boron oxide layer.
The grain diameter of the magnesium-doped lithium ferric manganese phosphate nuclear layer is 5 mu m, and the thickness of the boron-containing coating layer is 1 nm.
Comparative example 1
The only difference from example 1 is that the boron-containing cladding layer is not coated.
And (3) performance characterization:
assembling the battery: the modified lithium ferric manganese phosphate material in the above example or the lithium ferric manganese phosphate material in the comparative example (96.8 wt%) was stirred with a conductive agent (2 wt%) and a PVDF glue solution (1.2 wt%) to form a uniformly dispersed positive electrode slurry. Coating the prepared slurry on an aluminum foil, and drying for 10 hours in a vacuum oven at the temperature of 60 ℃; a metal lithium sheet is used as a negative electrode, a Celgard2400 microporous polypropylene membrane is used as a diaphragm, the volume ratio of a solvent to Ethylene Carbonate (EC)/dimethyl carbonate (DMC) is 1:1, and LiPF is 1mol/L6And (3) assembling the button battery 2032 in a glove box filled with dry high-purity argon as electrolyte.
(1) Testing the efficiency and the cycle performance for the first time: first charge/discharge efficiency at a current density of 17mA/g in a voltage range of 2.5-4.5V and cycle performance curve. The primary efficiency results are shown in table 1, the cycle performance curves are shown in fig. 1, and the capacity retention rates after 80 cycles of each battery are shown in table 2.
(2) And (3) rate performance test: the above examples and the comparative batteries were subjected to rate tests at current densities of 17mA/g, 34mA/g, 85mA/g, 340mA/g and 17mA/g, respectively. Wherein, the last 17mA/g is discharged under different multiplying power, and then returns to the initial small current discharge to observe the reversible capacity, and the performance results are shown in the following table 3.
TABLE 1
| Group of | Example 1 | Example 2 | Example 3 | Example 4 | Comparative example 1 |
| First time efficiency | 88.92％ | 87.93％ | 87.80％ | 86.12％ | 83.93％ |
TABLE 2
| Group of | Example 1 | Example 2 | Example 3 | Example 4 | Comparative example 1 |
| Capacity retention rate | 81.8％ | 78.7％ | 78.5％ | 78.4％ | 61.6％ |
TABLE 3
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. The modified lithium ferric manganese phosphate material is characterized by comprising a magnesium-doped lithium ferric manganese phosphate nuclear layer and a boron-containing coating layer coated on the surface of the magnesium-doped lithium ferric manganese phosphate nuclear layer.
2. The modified lithium ferric manganese phosphate material of claim 1, wherein the material of the magnesium-doped lithium ferric manganese phosphate core layer is Li (Fe)yMn1-y)1-xMgxPO4，x＝0.01～0.05，y＝0.57～0.62。
3. The modified lithium ferric manganese phosphate material of claim 1 or 2, wherein the material of the boron-containing cladding layer is boron oxide.
4. The modified lithium ferric manganese phosphate material of claim 3, wherein the particle size D50 of the magnesium-doped lithium ferric manganese phosphate core layer is 5-20 μm, and the thickness of the boron-containing cladding layer is 1-20 nm.
5. A method for preparing a modified lithium ferric manganese phosphate material according to any one of claims 1 to 4, characterized by comprising the following steps:
mixing a manganese source, a phosphorus source, an iron source, a lithium source, a magnesium source and water to form an intermediate reaction solution;
drying and pre-calcining the intermediate reaction solution in sequence to obtain a nuclear layer precursor;
and mixing the nuclear layer precursor with a boron source, and then roasting to obtain the modified lithium ferric manganese phosphate material.
6. The production method according to claim 5,
the boron source is boric acid and/or boron nitrate; preferably, the boron source accounts for 30-60 wt% of the total weight of the boron source and the core layer precursor, and preferably 45-60 wt%;
the magnesium source is Mg (CH)3COO)2And/or Mg (OH)2；
Preferably, the molar ratio of the manganese source, the phosphorus source, the iron source, the lithium source and the magnesium source is (0.38-0.44): 1, (0.57-0.62): 1.05, (0.01-0.05);
preferably, the lithium source is CH3COOLi·2H2O and/or LiOH; the manganese source is Mn (CH)3COO)2·4H2O and/or MnSO4(ii) a The phosphorus source is NH4H2PO4(ii) a The iron source is FeCl2·4H2O and/or Fe (CH)3COO)2。
7. The production method according to claim 5 or 6,
in the pre-calcination treatment process, the treatment temperature is 300-450 ℃, and the treatment time is 5-8 h;
in the roasting treatment process, the treatment temperature is 650-850 ℃, and the treatment time is 6-24 h.
8. The production method according to claim 5 or 6, characterized in that before subjecting the core layer precursor and the boron source to the baking treatment, the method further comprises subjecting the core layer precursor to a grinding treatment; preferably, the grinding treatment process comprises roll crushing treatment and ultracentrifugal grinding and crushing treatment which are sequentially carried out; preferably, the particle size of the core layer precursor is 5-20 μm.
9. A cathode material, characterized by being the modified lithium ferric manganese phosphate material according to any one of claims 1 to 4, or the modified lithium ferric manganese phosphate material prepared by the preparation method according to any one of claims 5 to 8.
10. A lithium ion battery, which comprises a positive electrode, wherein the positive electrode comprises a positive electrode current collector and a positive electrode active layer positioned on the surface of the positive electrode current collector, and the positive electrode active layer comprises a positive electrode material, a conductive agent and a binder, and is characterized in that the positive electrode material is the modified lithium ferric manganese phosphate material in any one of claims 1 to 4 or the modified lithium ferric manganese phosphate material prepared by the preparation method in any one of claims 5 to 8.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114400308A (en) * | 2021-12-30 | 2022-04-26 | 浙江浙能中科储能科技有限公司 | Preparation and application method of modified manganese dioxide electrode material |
| CN115724418A (en) * | 2022-12-09 | 2023-03-03 | 广东邦普循环科技有限公司 | Lithium iron manganese phosphate positive electrode material, preparation method thereof and battery |
| CN115863613A (en) * | 2023-02-28 | 2023-03-28 | 四川轻化工大学 | Lithium manganese iron phosphate coated modified high-nickel positive electrode material, and preparation method and application thereof |
| US11888154B2 (en) | 2022-03-04 | 2024-01-30 | Contemporary Amperex Technology Co., Limited | Positive electrode sheet, secondary battery, battery module, battery pack and electrical apparatus |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102709554A (en) * | 2012-02-22 | 2012-10-03 | 上海大学 | LiMnPO4/C composite cathode material preparation method for lithium ion battery |
| CN102956887A (en) * | 2012-11-14 | 2013-03-06 | 佛山市德方纳米科技有限公司 | Preparation method of nano-grade lithium manganese phosphate anode material |
| CN103000888A (en) * | 2012-11-28 | 2013-03-27 | 上海交通大学 | Composite anode material LiMnPO4-Li3V2(PO4)3/C for lithium ion battery and preparation method of material |
| CN103400968A (en) * | 2013-08-09 | 2013-11-20 | 天津巴莫科技股份有限公司 | Lithium manganese phosphate-capacitance carbon composite material, preparation method thereof, and lithium ion capacitance battery |
-
2021
- 2021-05-07 CN CN202110496178.XA patent/CN113224278B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102709554A (en) * | 2012-02-22 | 2012-10-03 | 上海大学 | LiMnPO4/C composite cathode material preparation method for lithium ion battery |
| CN102956887A (en) * | 2012-11-14 | 2013-03-06 | 佛山市德方纳米科技有限公司 | Preparation method of nano-grade lithium manganese phosphate anode material |
| CN103000888A (en) * | 2012-11-28 | 2013-03-27 | 上海交通大学 | Composite anode material LiMnPO4-Li3V2(PO4)3/C for lithium ion battery and preparation method of material |
| CN103400968A (en) * | 2013-08-09 | 2013-11-20 | 天津巴莫科技股份有限公司 | Lithium manganese phosphate-capacitance carbon composite material, preparation method thereof, and lithium ion capacitance battery |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114400308A (en) * | 2021-12-30 | 2022-04-26 | 浙江浙能中科储能科技有限公司 | Preparation and application method of modified manganese dioxide electrode material |
| US11888154B2 (en) | 2022-03-04 | 2024-01-30 | Contemporary Amperex Technology Co., Limited | Positive electrode sheet, secondary battery, battery module, battery pack and electrical apparatus |
| CN115724418A (en) * | 2022-12-09 | 2023-03-03 | 广东邦普循环科技有限公司 | Lithium iron manganese phosphate positive electrode material, preparation method thereof and battery |
| CN115724418B (en) * | 2022-12-09 | 2024-05-10 | 广东邦普循环科技有限公司 | Lithium iron manganese phosphate positive electrode material, preparation method thereof and battery |
| CN115863613A (en) * | 2023-02-28 | 2023-03-28 | 四川轻化工大学 | Lithium manganese iron phosphate coated modified high-nickel positive electrode material, and preparation method and application thereof |
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