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Preparation method of positive electrode material of lithium ion cell

A technology for lithium-ion batteries and cathode materials, which is applied in electrode manufacturing, battery electrodes, circuits, etc., can solve the problems of difficult to control grain size and distribution, lack of uniformity, and high energy consumption, and achieve easy industrial scale production, increase The effect of surface popularity, uniform particle size distribution

Inactive Publication Date: 2009-04-08
KUNMING UNIV OF SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Its parameters are very ideal, but its disadvantage is that its products only use rare earth materials to dope lithium iron phosphate, and the whole process takes a long time and consumes a lot of energy.
In addition, in the process steps of this technology, only the raw materials are mixed by ball milling, the uniformity of raw material mixing is lacking, and it is not easy to control the size and distribution of grains

Method used

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  • Preparation method of positive electrode material of lithium ion cell
  • Preparation method of positive electrode material of lithium ion cell
  • Preparation method of positive electrode material of lithium ion cell

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Embodiment 1: Li 3 PO 4 , Fe 2 C 2 o 4 2H 2 O, (NH 4 ) 2 HPO 4 and Ti(C 4 h 9 o 4 ) 4 Molar ratio Li:Fe:PO 4 :Ti=1:0.99:1:0.01 for batching, pour the prepared powder into a container, and add an appropriate amount of alcohol as a dispersant. Fix the container in an ultrasonic instrument, perform mechanical activation at a stirring speed of 200r / min and an ultrasonic frequency of 40kHz, and control the time within 4 hours. After completion, dry it below 100°C to obtain powder and send it into a tube furnace. Calcined at 400°C for 6 hours under an Ar gas protective atmosphere to obtain doped LiFePO 4Precursor powder. Add acetylene black containing 5wt% C to this powder, ball mill for 4 hours, then dry below 100°C, put the dried powder in a tube furnace, and heat it at 650°C, N 2 Calcined under protective atmosphere for 10 hours. The calcined material is crushed and sieved to obtain titanium-doped carbon-coated lithium iron phosphate LiFe 0.99 Ti 0.01 PO ...

Embodiment 2

[0026] Embodiment 2: Li 2 CO 3 , Fe 2 C 2 o 4 2H 2 O, (NH 4 ) 2 HPO 4 and Cr(C 2 h 3 o 2 ) 3 Molar ratio Li:Fe:PO 4 : Cr=(1:0.99:1:0.01) for batching, pour the prepared powder into a container, and add an appropriate amount of deionized water as a dispersant. Fix the container in an ultrasonic instrument, perform mechanical activation at a stirring speed of 300r / min and an ultrasonic frequency of 59kHz, and control the time within 6 hours. After completion, dry it below 100°C to obtain powder and send it into a tube furnace. At 400°C, N 2 Calcined for 8 hours under a protective atmosphere to obtain doped LiFePO 4 Precursor powder. Glucose containing 10wt% C was added to the powder, ball milled for 4 hours, and then dried below 100°C, and the dried powder was placed in a tube furnace at 700°C, N 2 Calcined under protective atmosphere for 8 hours. The calcined material is crushed and sieved to obtain chromium-doped carbon-coated lithium iron phosphate LiFe 0.99...

Embodiment 3

[0027] Embodiment 3: with Li 2 CO 3 , Fe 2 C 2 o 4 2H 2 O, (NH 4 ) 2 HPO 4 and Mg(C 2 h 3 o 2 ) 2 4H 2 O molar ratio Li:Fe:PO 4 :Mg=1:0.98:1:0.02 for batching, pour the prepared powder into a container, and add an appropriate amount of acetone as a dispersant. Fix the container in an ultrasonic instrument, perform mechanical activation at a stirring speed of 400r / min and an ultrasonic frequency of 59kHz, and control the time for 10 hours. After completion, dry it below 100°C to obtain powder and send it into a tube furnace. At 400°C, N 2 Calcined for 10 hours under a protective atmosphere to obtain doped LiFePO 4 Precursor powder. Add 10wt% sucrose containing C to the powder, mill it for 4 hours, and then dry it below 100°C, put the dried powder in a tube furnace, and heat it at 750°C, N 2 Calcined under protective atmosphere for 12 hours. The calcined material is crushed and sieved to obtain magnesium-doped carbon-coated lithium iron phosphate LiFe 0.98 Mg ...

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Abstract

The invention provides a method for manufacturing positive materials of lithium ion batteries, comprising the steps: lithium salt, ferric salt, phosphate salt and metalic contamination are mixed together according to certain molar proportion; the mixed materials are added with right amount of dispersant, are treated by mechanical activation and mixing, and then are pretreated at a certain temperature; the obtained material is added with right amount of carbon, and finally is calcined and synthesized at the high temperature, so that metalic contamination carbon-coated lithium iron phosphate positive material is obtained. On the one hand, by adopting ultrasonic cavitation mechanical activation and mixing treatment, the uniformity of the mixed material is ensured, and the reaction temperature and the synthesis time are reduced; on the other hand, as the LiFePO4 is coated and intermingled to obtain uniform pure phase product with small crystal grains. The manufactured positive materials are low in price, simple in process flow, low in reaction temperature, short in the whole preparation process time, energy-saving, free from contamination and easy for industrialized large-scale production.

Description

Technical field: [0001] The invention relates to a preparation method of a positive electrode material for a lithium ion battery, in particular to a preparation method of a metal doped carbon-coated lithium ferrous phosphate positive electrode material for a lithium ion battery, and belongs to the field of material synthesis. Background technique: [0002] Olivine LiFePO 4 In recent years, it has become a research hotspot of cathode materials for lithium-ion batteries. In 1997, Goodenough et al. studied a series of transition metal polyanion compounds M 2 (XO 4 ) 3 (M=Ti, Fe, Nb, V, X=S, P, As, Mo, W), found olivine structure LiFePO 4 It has good lithium ion intercalation and deintercalation capabilities. When 1 mole of lithium ions are deintercalated from the structure, LiFePO 4 The theoretical discharge specific capacity is as high as 170mAh / g, and the discharge platform is stable at around 3.4V. Due to the abundant resources of this material, good environmental com...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/04H01M4/1397
CPCY02E60/12Y02E60/10
Inventor 姚耀春杨斌戴永年胡成林于逢捷易惠华梁风廖文明李永梅秦博
Owner KUNMING UNIV OF SCI & TECH