Method for preparing lithium iron manganese phosphate-carbon composite material and lithium iron manganese phosphate-carbon composite material

Abstract

The invention discloses a method for preparing a lithium iron manganese phosphate-carbon composite material and a lithium iron manganese phosphate-carbon composite material. The method comprises the following steps: (1) respectively preparing a soluble manganese-containing phosphate solution A, a soluble organic iron salt solution B, a soluble organic manganese salt solution C and a soluble organic lithium salt solution D; (2) mixing the solution A, B, C and D are mixed according to a predetermined element molar ratio to obtain a precursor solution; (3) the precursor solution obtained in step (2) is dried and granulated to obtain lithium manganese iron phosphate precursor powder; (4) the The precursor powder obtained in step (3) is sintered in a protective atmosphere to obtain a sintered material; (5) the material obtained in step (4) is pulverized, refined and vacuum packed to obtain lithium iron manganese phosphate-carbon composite material . The method of the invention is simple and feasible, and is suitable for large-scale industrial production. The obtained material can be used as a positive electrode active material for lithium ion batteries, and has low resistivity and excellent electrochemical performance.

Description

technical field

[0001] The invention relates to a preparation method of a positive electrode active material for a lithium ion battery and a corresponding positive electrode active material for a lithium ion battery, in particular, the present invention relates to a method for preparing a lithium iron manganese phosphate-carbon composite material by using a soluble metal salt in a liquid phase, and a method for preparing a lithium iron manganese phosphate-carbon composite material by using a soluble metal salt The lithium iron manganese phosphate-carbon composite material prepared by the method. Background technique

[0002] In the context of today's energy crisis and energy transformation, replacing traditional fossil fuels with electricity is in line with the development direction of today's social energy industry. The key to the development of the new energy industry is the development and breakthrough of secondary chemical power sources and new energy storage technologie...

Examples

preparation example Construction

[0089] 1.1 Preparation of soluble manganese-containing phosphate solution

[0090]The soluble manganese-containing phosphate is added to deionized water according to the solute mass fraction of 10% to 60%, and phosphoric acid can be optionally added as a regulator of phosphorus content and pH value to prevent the formation of solid insolubles, phosphoric acid (according to pure The addition amount of phosphoric acid (calculated as phosphoric acid) does not exceed 15% of the mass of the manganese-containing phosphate, and the solution A is prepared.

[0091] The soluble manganese-containing phosphate may be manganese dihydrogen phosphate.

[0092] The phosphoric acid can be pure phosphoric acid or an aqueous phosphoric acid solution, such as concentrated phosphoric acid.

[0093] In this field, commonly used manganese sources can be divided into insoluble manganese sources and soluble manganese sources according to water solubility. Insoluble manganese sources mainly include m...

Embodiment 1

[0148] (1) Preparation of soluble salt solution

[0149] a. Weigh 27.92kg manganese dihydrogen phosphate dihydrate (wherein by mass, the Mn content is 15.01%, the P content is 21.90%, the same below), 1.44kg concentrated phosphoric acid (mass fraction is 85%) in 100kg deionized water , at a temperature of 45 °C, stirring and dissolving to obtain a manganese dihydrogen phosphate solution;

[0150] b. Weigh 28.00kg of ferric citrate pentahydrate (purity ≥ 99.5% by mass, the same below) in 60kg of deionized water, at a temperature of 30 ° C, stir and dissolve to obtain a ferric citrate solution;

[0151] c. Weigh 11.93kg of manganese acetate tetrahydrate (by mass, purity ≥99.5%, the same below) in 20kg of deionized water, stir and dissolve to obtain a manganese acetate solution;

[0152] d. Weigh 21.46kg of lithium acetate dihydrate (by mass, purity ≥99.5%, the same below) in 40kg of deionized water, stir and dissolve to obtain a lithium acetate solution;

[0153] (2) According...

Embodiment 2

[0158] The main difference between Example 2 and Example 1 is that ferrous lactate was used instead of ferric citrate pentahydrate as a soluble organic iron salt to prepare a lithium iron manganese phosphate-carbon composite material. details as follows:

[0159] (1) Preparation of soluble salt solution

[0160] a. Weigh 27.92kg manganese dihydrogen phosphate dihydrate, 0.46kg concentrated phosphoric acid (mass fraction is 85%) in 80kg deionized water, at a temperature of 65°C, stir and dissolve to obtain a manganese dihydrogen phosphate solution;

[0161] B. take by weighing 22.86kg ferrous lactate trihydrate (by mass, purity ≥ 99.5%, the same below), 1.14kg ascorbic acid in 200kg deionized water, at a temperature of 65 ℃, stirring and dissolving to obtain a ferrous lactate solution;

[0162] c. Weigh 10.39kg of manganese acetate tetrahydrate in 35kg of deionized water, stir and dissolve to obtain manganese acetate solution;

[0163] d. Weigh 22.27kg of lithium acetate dihy...

technical field

[0001] The invention relates to a preparation method of a positive electrode active material for a lithium ion battery and a corresponding positive electrode active material for a lithium ion battery, in particular, the present invention relates to a method for preparing a lithium iron manganese phosphate-carbon composite material by using a soluble metal salt in a liquid phase, and a method for preparing a lithium iron manganese phosphate-carbon composite material by using a soluble metal salt The lithium iron manganese phosphate-carbon composite material prepared by the method. Background technique

[0002] In the context of today's energy crisis and energy transformation, replacing traditional fossil fuels with electricity is in line with the development direction of today's social energy industry. The key to the development of the new energy industry is the development and breakthrough of secondary chemical power sources and new energy storage technologie...

Examples

preparation example Construction

[0089] 1.1 Preparation of soluble manganese-containing phosphate solution

[0090]The soluble manganese-containing phosphate is added to deionized water according to the solute mass fraction of 10% to 60%, and phosphoric acid can be optionally added as a regulator of phosphorus content and pH value to prevent the formation of solid insolubles, phosphoric acid (according to pure The addition amount of phosphoric acid (calculated as phosphoric acid) does not exceed 15% of the mass of the manganese-containing phosphate, and the solution A is prepared.

[0091] The soluble manganese-containing phosphate may be manganese dihydrogen phosphate.

[0092] The phosphoric acid can be pure phosphoric acid or an aqueous phosphoric acid solution, such as concentrated phosphoric acid.

[0093] In this field, commonly used manganese sources can be divided into insoluble manganese sources and soluble manganese sources according to water solubility. Insoluble manganese sources mainly include m...

Embodiment 1

[0148] (1) Preparation of soluble salt solution

[0149] a. Weigh 27.92kg manganese dihydrogen phosphate dihydrate (wherein by mass, the Mn content is 15.01%, the P content is 21.90%, the same below), 1.44kg concentrated phosphoric acid (mass fraction is 85%) in 100kg deionized water , at a temperature of 45 °C, stirring and dissolving to obtain a manganese dihydrogen phosphate solution;

[0150] b. Weigh 28.00kg of ferric citrate pentahydrate (purity ≥ 99.5% by mass, the same below) in 60kg of deionized water, at a temperature of 30 ° C, stir and dissolve to obtain a ferric citrate solution;

[0151] c. Weigh 11.93kg of manganese acetate tetrahydrate (by mass, purity ≥99.5%, the same below) in 20kg of deionized water, stir and dissolve to obtain a manganese acetate solution;

[0152] d. Weigh 21.46kg of lithium acetate dihydrate (by mass, purity ≥99.5%, the same below) in 40kg of deionized water, stir and dissolve to obtain a lithium acetate solution;

[0153] (2) According...

Embodiment 2

[0158] The main difference between Example 2 and Example 1 is that ferrous lactate was used instead of ferric citrate pentahydrate as a soluble organic iron salt to prepare a lithium iron manganese phosphate-carbon composite material. details as follows:

[0159] (1) Preparation of soluble salt solution

[0160] a. Weigh 27.92kg manganese dihydrogen phosphate dihydrate, 0.46kg concentrated phosphoric acid (mass fraction is 85%) in 80kg deionized water, at a temperature of 65°C, stir and dissolve to obtain a manganese dihydrogen phosphate solution;

[0161] B. take by weighing 22.86kg ferrous lactate trihydrate (by mass, purity ≥ 99.5%, the same below), 1.14kg ascorbic acid in 200kg deionized water, at a temperature of 65 ℃, stirring and dissolving to obtain a ferrous lactate solution;

[0162] c. Weigh 10.39kg of manganese acetate tetrahydrate in 35kg of deionized water, stir and dissolve to obtain manganese acetate solution;

[0163] d. Weigh 22.27kg of lithium acetate dihy...

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