Method for manufacturing LiFePO (lithium iron phosphate)/lithium cobaltate composite anode

A lithium iron phosphate and composite positive electrode technology, which is applied in battery electrodes, electrical components, circuits, etc., can solve the problems of not fundamentally improving the material structure and hindering the performance of LiFePO4, achieving low cost, simple method, and avoiding complicated processes. Effect

Inactive Publication Date: 2012-01-04
QINGDAO QIANYUN HIGH TECH NEW MATERIAL
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Carbon coating of the material can form a carbon coating layer on the surface of the grain, improve the electronic conductivity, and prevent the grain from growing, but this surface modification process cannot fundamentally improve the structure of the material, which hinders the further improvement of the performance of LiFePO4

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] First, weigh 297.6 grams of lithium iron phosphate, 11.2 grams of PVDF, and 11.2 grams of SP according to the weight ratio, and add 16 grams of lithium cobalt oxide; mix and stir the weighed ingredients for 4 hours, and coat them evenly with a coater. Electrode sheet: Put the obtained electrode sheet in a vacuum drying box and dry at 100°C for 11 hours for use. Make a battery as a positive electrode. Use metal lithium sheet as negative electrode, electrolyte 1MliPF 6 / EC: DEC (1∶1), 0.1C charge and discharge at room temperature, after testing, the conductivity of the lithium iron phosphate cathode is 1.3×10 -3 mS / m, the initial battery capacity is 144mAh / g (2.5-4.3V), and the capacity retention rate is 92% after 300 cycles.

Embodiment 2

[0020] First, weigh 297.6 grams of lithium iron phosphate, 11.2 grams of PVDF, and 11.2 grams of SP according to the weight ratio, and add 32 grams of lithium cobalt oxide; mix and stir the weighed ingredients for 6 hours, and coat them evenly with a coater. Electrode sheet: Put the obtained electrode sheet in a vacuum drying box and dry at 105°C for 12 hours for use. Use metal lithium sheet as negative electrode, electrolyte 1MliPF 6 / EC: DEC (1∶1), 0.1C charge and discharge at room temperature, after testing, the conductivity of the lithium iron phosphate cathode is 1.4×10 -3 mS / m, the initial battery capacity is 150mAh / g (2.5-4.3V), and the capacity retention rate is 90% after 300 cycles.

Embodiment 3

[0022] First, weigh 297.6 grams of lithium iron phosphate, 11.2 grams of PVDF, and 11.2 grams of SP according to the weight ratio, and add 64 grams of lithium cobalt oxide; mix and stir the weighed ingredients for 8 hours, and use a coater to evenly coat the electrode sheet ; Put the obtained electrode sheet into a vacuum drying oven at 110 ℃ for 13 hours, and then set aside. Use metal lithium sheet as negative electrode, electrolyte 1MliPF 6 / EC: DEC (1∶1), 0.1C charge and discharge at room temperature, after testing, the conductivity of the lithium iron phosphate cathode is 1.5×10 -3 mS / m, the initial battery capacity is 152mAh / g (2.5-4.3V), and the capacity retention rate is 87% after 300 cycles.

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Abstract

The invention discloses a method for manufacturing a LiFePO (lithium iron phosphate) / lithium cobaltate composite anode. The method comprises the following steps: 1, exactly weighing LiFePO, PVDF (polyvinylidene fluoride) and SP based on the weight ratio of 93:3.5:3.5, and adding 5-20% of lithium cobaltate by weight; 2, mixing and stirring the components weighed in the step 1 for 4-8 hours, and coating evenly by using a coating machine to manufacture an electrode plate; and 3, drying the electrode plate obtained in the step 2 in a vacuum drying oven for 11-13 hours at the temperature of 100-110 DEG C. By adding SP into the LiFePO, the electrical conductivity of the electrode is improved; by adding the PVDF into the LiFePO, the adhesive strength and firmness of an anode coating are improved; a metal ion cobalt doping way is adopted to improve the conductivity of the LiFePO material anode and avoid the influence of high temperature on carbon loss in the carbon cladding process as well as the complicated production process; the manufacturing method is simple, low in the energy consumption and high in efficiency; and the raw materials are obtained easily and the cost is low.

Description

Technical field [0001] The invention relates to a method for preparing a lithium iron phosphate / lithium cobalt oxide composite positive electrode, which is used for lithium ion batteries and belongs to the field of new energy materials. Background technique [0002] The world energy crisis and environmental protection have become the main concerns of people, and the search for new and clean energy has become the focus. As one of the new energy sources, lithium ion has become a research hotspot because of its high energy, good safety performance, low cost, and environmental friendliness. Battery lithium iron phosphate cathode material has a very attractive prospect in power battery applications due to its outstanding safety and low price. It is considered to mark the arrival of a new era of lithium ion batteries. [0003] LiFePO 4 The biggest obstacle to large-scale application is its relatively low ion conductivity and electronic conductivity, which results in poor discharge perfo...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/62H01M4/58
CPCY02E60/10
Inventor 孙琦于观霞吴刘杰
Owner QINGDAO QIANYUN HIGH TECH NEW MATERIAL
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