Making method for positive material LiFePO4 of poly-aniline coated lithium ion battery

A positive electrode material, ion battery technology, applied in the direction of electrode manufacturing, battery electrodes, chemical instruments and methods, etc., can solve the problems of poor high-temperature cycle performance, unsafe overcharging, impossibility of large-capacity battery application, low capacity, etc., to achieve Effects of long cycle life, high specific capacity, and high discharge capacity

Inactive Publication Date: 2010-06-02
XIANGTAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, the positive electrode materials used in lithium-ion batteries are mainly lithium-intercalated transition metal oxides, mainly using layered LiCoO 2 , the material has been widely used in small batteries, but in addition to the constraints of cobalt resources, the unsafe overcharge determines that it cannot be applied in large-capacity batteries
It is expected that spinel LiMn 2 o 4 Can rely on its cheap and relatively LiCoO 2 The advantages of safety play a role in large-capacity batteries, but a good solution has not been found for its shortcomings of low capacity and poor high-temperature cycle performance, so it still cannot be promoted in actual batteries
So far, there has been no literature report on the use of in-situ polymerization to coat polyaniline on the surface of lithium iron phosphate particles.

Method used

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  • Making method for positive material LiFePO4 of poly-aniline coated lithium ion battery
  • Making method for positive material LiFePO4 of poly-aniline coated lithium ion battery
  • Making method for positive material LiFePO4 of poly-aniline coated lithium ion battery

Examples

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Effect test

Embodiment 1

[0021] Accurately weigh Li according to the stoichiometric ratio 2 CO 3 , FeC 2 o 4 2H 2 O, (NH 4 ) 2 HPO 4 , placed in a ball mill jar, the ratio of large and small balls is 1:4, and ball milled for 10 hours until the mixture is uniform. Then the reactant was placed in a quartz boat and put into a tube furnace to raise the temperature under the protection of argon. First raise the temperature to 300°C at 5°C / min, keep the temperature for 8 hours, then cool it down to room temperature naturally, take it out and grind it, put it in a tube furnace again, raise it to 700°C at 10°C / min, keep it warm for 20 hours, then cool it down naturally to obtain LiFePO 4 . Weigh 4 g LiFePO 4 Add the powder into 0.1mol / L HCl and stir for 30 minutes, add 1mL of aniline monomer and stir for 30 minutes, dissolve 1.28 grams of ammonium persulfate in 0.1mol / L HCl and add dropwise to the mixed solution, react at room temperature, and continue Stirring, nitrogen protection. After reacting ...

Embodiment 2

[0023] Accurately weigh Fe(NO 3 ) 3 9H 2 O, Li(CH 3 COO)·2H 2 O, dissolved in distilled water, adding excess HOCH 2 COOH, the Fe 3+ reduced to Fe 2+ , then add the stoichiometric ratio of NH 4 h 2 PO 4 , adjust the pH value to 8.5-9.2 with ammonia water, heat at 60°C for 24h to obtain a gel, heat the obtained gel, protect it with argon, pre-decompose at 300°C for 3h, grind and press it into tablets after cooling. Calcined at 600 °C for 20 h to obtain LiFePO 4 sample. Weigh 4 g LiFePO 4 Add the powder into 0.1mol / L HCl and stir for 30 minutes, add 1mL of aniline monomer and stir for 30 minutes, dissolve 1.28 grams of ammonium persulfate in 0.1mol / L HCl and add dropwise to the monomer solution, react at room temperature, Stirring was continued under nitrogen protection. After reacting for 12 hours, stop stirring, filter and wash until the filtrate is colorless. Then vacuum-dried at 60° C. to obtain polyaniline-coated lithium iron phosphate. Using a lithium sheet a...

Embodiment 3

[0025] LiFePO was prepared under the same conditions as in Example 1 4 . Weigh 4.5 g LiFePO 4Add the powder into 2mol / L HCl and stir for 30 minutes, add 0.5mL aniline monomer and stir for 30 minutes, dissolve 0.64 g of ammonium persulfate in 2mol / L HCl and add dropwise to the monomer solution, react at room temperature, and continue Stirring, nitrogen protection. After reacting for 6 hours, stop stirring, filter and wash until the filtrate is colorless. Then vacuum-dried at 60° C. to obtain polyaniline-coated lithium iron phosphate. Using a lithium sheet as the negative electrode, the first discharge specific capacity of the polyaniline-coated lithium iron phosphate at room temperature was measured to be 133mAh / g, and the capacity was still 110mAh / g after 50 cycles at 1C.

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Abstract

The invention discloses a method for preparing polyaniline coating Li-ion battery anode material LiFePO4. The method is coating polyaniline on the in-situ surface of the powder of Li-ion battery anodematerial LiFePO4. The method has the following favorable effects: the discharging voltage platform of the polyaniline coating anode material LiFePO4obtained is stable, the battery has higher specificcapacity up to one hundred and forty point three mAh / g, the granularity is distributed evenly, the grains are in good appearance and high in discharging capacity and long in cycling life, etc.

Description

technical field [0001] The invention relates to a preparation method of a positive electrode material of a lithium ion battery. Background technique [0002] Lithium-ion battery is a new generation of green high-energy battery with excellent performance, and has become one of the focuses of high-tech development. It stands out among many batteries with its high voltage, high capacity, low consumption, no memory effect, no pollution, small size, low internal resistance, low self-discharge, and many cycles. The application fields of lithium-ion batteries continue to expand, and their applications have penetrated into many civilian and military fields including telephones, notebook computers, video cameras, and digital cameras. In addition, domestic and foreign countries are also competing to develop large-capacity lithium-ion batteries required for automobiles, aerospace and energy storage. Cathode materials are an important part of lithium-ion batteries. At present, the po...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01M4/04B22F1/02C01B25/45H01M4/58H01M4/36
CPCY02E60/10
Inventor 雷钢铁易晓华陈效兰汪磊周姬李朝晖高德淑
Owner XIANGTAN UNIV
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