Preparation method for lithium iron phosphate material of positive electrode of lithium ion secondary battery

A technology of lithium iron phosphate and positive electrode materials, which is applied in the direction of battery electrodes, circuits, electrical components, etc., can solve the problems of low electronic conductivity, lithium ion diffusion rate, poor conductivity of lithium iron phosphate, and high cost, and achieve easy control of process parameters, The synthesis process is easy and the material particles are uniform

Inactive Publication Date: 2013-03-20
ZHEJIANG NARADA POWER SOURCE CO LTD +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003]Although LiFePO4 has many advantages, it still has the following two shortcomings that hinder its practical application process: (1), Electronic conductivity and lithium ion diffusion rate are low, resulting in initial capacity loss and poor high-rate charge-discharge performance; (2), it is difficult to control the purity of LiFePO4 during the synthesis process, even if the synthesis conditions are strictly controlled , it is still unavoidable to completely avoid the oxidation of Fe3+. At present, most researches often use expensive Fe3+ compounds as iron sources, which increases the preparation cost
(3) The tap density of LiFePO4 is low, resulting in low volume specific energy
However, it is difficult

Method used

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  • Preparation method for lithium iron phosphate material of positive electrode of lithium ion secondary battery
  • Preparation method for lithium iron phosphate material of positive electrode of lithium ion secondary battery
  • Preparation method for lithium iron phosphate material of positive electrode of lithium ion secondary battery

Examples

Experimental program
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Example Embodiment

[0022] Example 1, reference figure 1 :

[0023] Take 639 grams of lithium carbonate, 2500 grams of iron phosphate, 4.1 grams of nickel acetate, 4.12 grams of cobalt acetate tetrahydrate, 20.5 grams of ammonium molybdate, 50.4 grams of ammonium tungstate, and 414 grams of rock sugar.

[0024] Add 1452 grams of deionized water to the stirring mill, and add the above materials to the stirring mill in turn. Stir for 3 hours.

[0025] The above mixture was diluted to a solid content of 18% after dilution, and then spray dried.

[0026] Take the spray-dried material and place it in a reducing atmosphere furnace, sinter it at a rate of 2°C / min in a nitrogen atmosphere, firstly raise the temperature to 200°C, keep it at 400°C for 4 hours, keep it at 700°C for 15 hours, and then lower the temperature. Lithium iron phosphate cathode material. The obtained positive electrode material is assembled into a simulated battery, the separator is celgard2400, the negative electrode is lithium metal s...

Example Embodiment

[0027] Example 2, reference figure 2 :

[0028] Take 543 grams of lithium carbonate, 2200 grams of iron phosphate, 7.1 grams of nickel acetate, 14 grams of cobalt acetate tetrahydrate, 30.4 grams of ammonium tungstate, and 361 grams of glucose.

[0029] Add 1390 grams of deionized water to the stirring mill and add the above-mentioned materials to the stirring mill in turn. Stir for 4 hours.

[0030] The above mixture is diluted to a solid content of 20% after dilution, and then spray dried.

[0031] Take the spray-dried material and place it in a reducing atmosphere furnace, sinter it at a rate of 2°C / min in a nitrogen atmosphere, firstly raise the temperature to 200°C, keep it at 400°C for 3 hours, keep it at 700°C for 15 hours, and then lower the temperature. Lithium iron phosphate composite cathode material.

[0032] The obtained positive electrode material is assembled into a simulated battery, the separator is celgard2400, the negative electrode is lithium metal sheet, and the ...

Example Embodiment

[0033] Example 3, reference image 3 :

[0034] Take 712 grams of lithium carbonate, 2899 grams of iron phosphate, 6.2 grams of nickel acetate, 10.3 grams of cobalt acetate tetrahydrate, 60.5 grams of ammonium molybdate, 68.2 grams of ammonium tungstate, and 457 grams of glucose.

[0035] Add 1800 grams of deionized water to the stirring mill, and add the above materials to the stirring mill in turn. Stir for 5 hours.

[0036] The above mixture was diluted to a solid content of 23% after dilution, and then spray dried.

[0037] Take the spray-dried material and place it in a reducing atmosphere furnace and sinter it at a rate of 2°C / min in a nitrogen atmosphere. Firstly, the temperature is raised to 200°C, held at 400°C for 5 hours, 700°C for 12 hours, and then cooled down. Lithium iron phosphate composite cathode material.

[0038] The obtained positive electrode material is assembled into a simulated battery, the separator is celgard2400, the negative electrode is lithium metal shee...

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Abstract

The invention provides a preparation method for a lithium iron phosphate material of a positive electrode of a lithium ion secondary battery. The preparation method comprises the following steps of: evenly mixing an iron source, a carbon source, a lithium source, a phosphate radial source and doping ions, conducting a drying procedure to obtain lithium iron phosphate precursor mixture, warming and heating the mixture in reducing atmosphere at the speed of 0.5-10 DEG C/min, preserving heat at 300-400 DEG C for 2-5hours, calcining at 500-850 DEG C for 3-28 hours, conducting furnace cooling to room temperature, smashing and classifying to obtain the lithium iron phosphate material of the positive electrode. The preparation method realizes the adoption of the low-cost ferric iron source, and achieves the doping of metal ions and further synthesis of the lithium iron phosphate composite material, and the prepared lithium iron phosphate material of the positive electrode is good in rate capability, easy for the synthesis process to control, and suitable for industrialized production, the prepared material is even in particles, high in crystallinity degree, good in discharge capacity, and stable in recycling property.

Description

Technical field: [0001] The invention belongs to a preparation method of a lithium ion battery cathode material, in particular to a method for preparing a high-rate lithium iron phosphate cathode material by multi-element doping. technical background: [0002] Olivine-type lithium iron phosphate is considered to be one of the best cathode materials for power batteries because of its low cost, environmental friendliness, long cycle life, good thermal stability and high safety performance. [0003] Although LiFePO 4 It has many advantages, but it also has the following two shortcomings that hinder its practical application process: (1), electronic conductivity and lithium ion diffusion rate are low, resulting in initial capacity loss and poor high-rate charge and discharge performance; ( 2), LiFePO during the synthesis process 4 It is difficult to control the purity of Fe, even if the synthesis conditions are strictly controlled, it is still impossible to completely avoid Fe...

Claims

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Application Information

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IPC IPC(8): H01M4/58
CPCY02E60/12Y02E60/10
Inventor 姜应律陈海涛陈蕾杨国凯熊辉
Owner ZHEJIANG NARADA POWER SOURCE CO LTD
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