Method for recovering waste/used lithium iron phosphate positive-pole material by acid leaching method

A technology for recycling and processing lithium iron phosphate, which is applied in battery recycling, recycling technology, recycling by waste collectors, etc., can solve the problems that iron phosphate is easy to stay in the solid phase, unfavorable for leaching, and low recovery rate

Active Publication Date: 2017-05-17
TIANQI LITHIUM CORP
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

This patent needs to undergo high-temperature heat treatment first, that is, the raw materials need to be roasted first, and then acid leached. In this way, during the roasting process, there is oxid

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  • Method for recovering waste/used lithium iron phosphate positive-pole material by acid leaching method

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[0037] Example 1

[0038] (1) Weigh 50 g of the positive electrode active material of the waste lithium iron phosphate battery and add it to the sulfuric acid solution. According to the stoichiometry of lithium in the raw material, the sulfuric acid excess is 0%. The liquid-solid ratio was controlled to 1.5:1, the leaching temperature was 25°C, and the leaching time was 30 minutes to obtain a suspension. The above suspension was filtered.

[0039] The waste lithium ion battery material processed in this step may be a waste lithium ion battery cathode material after pulverization and purification.

[0040] (2) Oxidation of ferrous ions: adjust the pH of the filtrate to be less than 1, add hydrogen peroxide to oxidize the ferrous ions, the excess hydrogen peroxide is 50%, the oxidation temperature is 45° C., and the reaction is carried out for 1 hour.

[0041] (3) Lithium and iron phosphorus are separated to prepare iron phosphate: LiOH is added to the reaction solution of step (2), t...

Example Embodiment

[0043] Example 2

[0044] (1) Weigh the anode active material 50 of the waste lithium iron phosphate battery and add it to the sulfuric acid solution. According to the stoichiometric calculation of lithium in the raw material, the sulfuric acid excess is 0%. The liquid-solid ratio was controlled to be 1.5:1, the leaching temperature was 60°C, and the leaching time was 100min to obtain a suspension. The above suspension was filtered.

[0045] The waste lithium ion battery material processed in this step may be a waste lithium ion battery cathode material that has been pulverized and purified.

[0046] (2) Oxidation of ferrous ions: adjust the pH of the filtrate to be less than 1, add hydrogen peroxide to oxidize the ferrous ions, the excess hydrogen peroxide is 100%, the oxidation temperature is 45°C, and the reaction is carried out for 5 hours.

[0047] (3) Lithium and iron phosphorus are separated to prepare iron phosphate: LiOH is added to the reaction solution in step (2), pH is ...

Example Embodiment

[0049] Example 3

[0050] (1) Weigh 50 g of the positive electrode active material of the waste lithium iron phosphate battery and add it to the sulfuric acid solution. According to the stoichiometric calculation of lithium in the raw material, the sulfuric acid excess is 100%. The liquid-solid ratio was controlled to 2.5:1, the leaching temperature was 60°C, and the leaching time was 100min to obtain a suspension. The above suspension was filtered.

[0051] The waste lithium ion battery material processed in this step may be a waste lithium ion battery cathode material that has been pulverized and purified.

[0052] (2) Oxidation of ferrous ions: adjust the pH of the filtrate to be less than 1, add hydrogen peroxide to oxidize the ferrous ions, the excess hydrogen peroxide is 100%, the oxidation temperature is 45°C, and the reaction is carried out for 2 hours.

[0053] (3) Preparation of iron phosphate by separation of lithium and iron and phosphorus: LiOH is added to the reaction ...

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Abstract

The invention belongs to the technical field of recovery of lithium-ion batteries and particularly relates to a method for recovering a waste/used lithium iron phosphate positive-pole material by an acid leaching method. The method provided by the invention comprises the following steps: (a) carrying out acid leaching: adding acid into the lithium iron phosphate positive-pole material for acid leaching so as to obtain a suspension, and carrying out filtration, so as to obtain filtrate; (b) carrying out oxidation: adjusting the pH value of the filtrate obtained in the step (a) to be smaller than 1, and adding an oxidant into the filtrate to oxidate ferrous ions in the filtrate into ferric ions, so as to obtain a mixed solution; (c) carrying out separation: adjusting the pH value of the mixed solution obtained in the step (b) to be 1.5 to 4, carrying out a reaction for 1 to 3 hours at the temperature of 60 DEG C to 95 DEG C so as to produce ferric phosphate precipitates, and carrying out filtrating and washing, thereby obtaining lithium-containing filtrate and ferric phosphate. The method provided by the invention is simple in process, continuous in cycle, low in cost and easy to industrialize and is environmentally friendly; the recovery rate of Li, Fe and P reaches 95% or more, subsequent prepared FePO4 is low in impurity content, the particle size is 1 to 6 microns, is uniform and is narrow in distribution, and the morphology is controllable, so that the FePO4 is battery-grade ferric phosphate.

Description

technical field [0001] The invention belongs to the technical field of lithium ion battery recycling, and in particular relates to a method for recycling and treating waste lithium iron phosphate cathode materials by an acid leaching method. Background technique [0002] At present, energy and environmental problems have increasingly become one of the most important problems that plague people. From wind energy, hydraulic power to nuclear energy, people have never stopped exploring new energy sources. However, due to the constraints of seasons, geographical location, technical level and other conditions, the emergence of these new energy sources has not completely solved the energy problem. With the rapid development of electronic technology, various electronic products such as mobile phones, digital cameras, and notebook computers continue to be miniaturized, and there is a wider demand for miniaturized power supplies, so various lithium-ion batteries have emerged as the t...

Claims

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Application Information

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IPC IPC(8): H01M10/54
CPCH01M10/54Y02W30/84
Inventor 曹乃珍高洁周梅田海英徐川杨柳李仕红
Owner TIANQI LITHIUM CORP
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