阅读说明：本技术 一种废旧锂离子电池材料为原料制备锂离子筛的方法 (Method for preparing lithium ion sieve by using waste lithium ion battery material as raw material ) 是由 刘炳光 袁永顺 葛梦丹 周蕾 李璐 王雪 李建生 李红斌 王晨 马晓宝 周素花 于 2021-08-02 设计创作，主要内容包括：本发明涉及一种在稀硫酸溶液中电解还原浸取废旧三元锂离子电池正极材料中的金属元素,同时电解氧化回收二氧化锰制备锰系锂离子筛的方法,选用钛蓝阴极,钛蓝用涤纶滤布袋包覆,内部装填从废旧三元锂离子电池中分离出的钴镍锰酸锂正极材料；选用钛板阳极,电解液温度90-100℃,阳极电流密度40-80A/m～(2)。本发明中将三元锂离子电池正极材料的电解还原浸取和电解氧化二氧化锰回收联合应用,使电流效率成倍提高,提高了工艺的技术经济性。本发明中将锰系锂离子筛中不稳定的三价锰电解氧化转化为四价锰,使其在稀酸溶液中不发生锰溶损,大幅延长了锰系锂离子筛的循环使用寿命。(The invention relates to a method for preparing a manganese-based lithium ion sieve by electrolyzing, reducing and leaching metal elements in a positive electrode material of a waste ternary lithium ion battery in a dilute sulfuric acid solution and electrolyzing, oxidizing and recovering manganese dioxide, wherein a titanium blue cathode is selected, the titanium blue is coated by a terylene filter cloth bag, and a cobalt nickel lithium manganate positive electrode material separated from the waste ternary lithium ion battery is filled in the titanium blue cathode; selecting titanium plate anode, electrolyte temperature is 90-100 ℃, anode current density is 40-80A/m 2 . In the invention, the electrolytic reduction leaching and electrolytic oxidation manganese dioxide recovery of the ternary lithium ion battery anode material are combinedThe current efficiency is improved by times by the combined application, and the technical economy of the process is improved. The invention converts unstable trivalent manganese in the manganese lithium ion sieve into tetravalent manganese through electrolytic oxidation, so that the manganese is not dissolved and damaged in the dilute acid solution, and the cycle service life of the manganese lithium ion sieve is greatly prolonged.)

1. A method for preparing a lithium ion sieve by taking a waste lithium ion battery material as a raw material is characterized in that metal elements in a positive electrode material of a waste ternary lithium ion battery are subjected to electrolytic reduction leaching in a 0.2-0.5mol/L sulfuric acid solution, manganese dioxide is recovered through electrolytic oxidation to prepare a manganese lithium ion sieve, a titanium blue cathode is selected, the titanium blue is coated with a terylene filter cloth bag, and a cobalt nickel lithium manganate positive electrode material separated from the waste ternary lithium ion battery is filled inside the titanium blue cathode; selecting titanium plate anode, electrolyte temperature is 90-100 ℃, anode current density is 40-80A/m²The method comprises the following specific operation steps:

(1) filling waste ternary lithium ion battery cobalt nickel lithium manganate material powder into cathode titanium blue coated by a polyester filter bag, and putting the cathode titanium blue and the polyester filter bag into an electrolytic cell; placing the titanium plate anode into an electrolytic tank, adding 0.2-0.5mol/L sulfuric acid as electrolyte, introducing direct current to start electrolysis at the temperature of 90-100 ℃, and controlling the current density of the anode to be 40-80A/m²；

(2) Electrolyzing and reducing high-valence cobalt nickel lithium manganate powder in a titanium blue cathode in sulfuric acid electrolyte to generate low-valence cobalt sulfate, nickel sulfate, manganese sulfate and lithium sulfate, dissolving the low-valence cobalt sulfate, nickel sulfate, manganese sulfate and lithium sulfate in the sulfuric acid electrolyte, electrolytically oxidizing the manganese sulfate in the electrolyte on the surface of a titanium plate anode to generate manganese dioxide, continuously plating the manganese dioxide on the surface of the titanium plate anode, and stopping electrolysis and supplementing the cobalt nickel lithium manganate material powder after most of the cobalt nickel lithium manganate material powder in the titanium blue cathode is dissolved;

(3) when the thickness of the electrolytic manganese dioxide coating reaches, stripping the electrolytic manganese dioxide coating from the titanium plate electrode to separate manganese salt from cobalt nickel sulfate;

(4) crushing an electrolytic manganese dioxide coating stripped from a titanium plate electrode, washing with water to deacidify, mixing and grinding with lithium hydroxide, controlling the molar ratio of Li to Mn to be 0.8-1.2, and roasting at the temperature of 450-550 ℃ for 2-6h to form a manganese-series lithium ion sieve precursor Li_1.33Mn_1.67O₄；

(5) Manganese series lithium ion sieve precursorLoading into titanium blue anode, coating titanium blue with terylene filter cloth bag, soaking in 0.2-0.5mol/L sulfuric acid solution, using titanium plate as cathode, and applying current density of 40-80A/m at anode²Electrolytic oxidation is carried out to completely oxidize unstable trivalent manganese in the manganese-based lithium ion sieve into tetravalent manganese, and simultaneously sulfuric acid electrolyte enables precursor Li of the manganese-based lithium ion sieve_1.33Mn_1.67O₄Desorbing lithium ions;

(6) removing lithium from the manganese-based lithium ion sieve precursor, removing the lithium from titanium blue, cleaning the lithium ion sieve precursor by using deionized water, and drying the lithium ion sieve precursor at the temperature of 100 ℃ to obtain the manganese dioxide with the chemical composition of MnO₂﹒0.5H₂Manganese-based lithium ion sieve of O;

(7) the manganese-based lithium ion sieve is immersed into 0.5g/L lithium chloride aqueous solution, the lithium adsorption capacity is measured to be 45-50mg/g, and the dissolution loss rate of the manganese-based lithium ion sieve after 10 times of adsorption and desorption circulation is 0.5-0.9%.

Technical Field

The invention relates to a method for preparing a lithium ion sieve by taking a waste lithium ion battery material as a raw material, in particular to a method for preparing a manganese-based lithium ion sieve by electrolyzing, reducing and leaching metal elements in a positive electrode material of a waste ternary lithium ion battery in a dilute sulfuric acid solution and electrolyzing, oxidizing and recovering manganese dioxide, belonging to the field of chemical engineering and new energy materials.

Technical Field

The anode material of the waste ternary lithium ion battery is a solid solution composite material of lithium cobaltate, lithium nickelate and lithium manganate, and because the economic value of manganese salt is much smaller than that of cobalt salt and nickel salt, the economic driving force and the enthusiasm of enterprises for separating and recovering manganese salt from waste battery materials are not high, but the new industry specification requires that the recovery rate of manganese must reach more than 98 percent so as to save resources and protect the environment. If the low-value manganese salt is further processed into the manganese lithium ion sieve, the method has great economic and social values.

The lithium ion sieve prepared by taking the waste lithium ion battery as the raw material has the advantages of excellent performance and technical economy, is particularly suitable for selectively adsorbing and extracting lithium from a low-concentration lithium-containing aqueous solution, can replace a manganese-based lithium ion sieve prepared by industrial raw materials, is applied to extracting lithium from the waste lithium ion battery material, extracting lithium from salt lake and extracting lithium from chemical pharmaceutical lithium-containing wastewater and waste residues, and has a wide market prospect, and the application field is continuously expanded.

The lithium ion sieve can efficiently adsorb and extract lithium from a low-concentration lithium-containing solution, and further process the lithium into battery-grade lithium carbonate or lithium hydroxide, thereby realizing the recycling of lithium resources. The lithium ion sieve becomes a king brand for recycling low-concentration lithium-containing solution, and the problems of large adsorption capacity, long service life and low cost in production and supply of the lithium ion sieve must be solved firstly.

The manganese-based lithium ion sieve is prepared by adopting a waste ternary lithium ion battery material, and firstly, the problem of separating manganese salt from a cobalt nickel lithium material is solved, the ternary lithium ion battery material is mineralized high-valence cobalt nickel manganese oxide, the mineralized high-valence cobalt nickel manganese oxide can be efficiently leached or dissolved by an acid, alkali or complex compound aqueous solution only by reducing the mineralized high-valence cobalt nickel manganese oxide into the low-valence cobalt nickel manganese oxide, and the leaching rate of metal can be improved only by consuming a large amount of chemical reducing agents, acids, alkalis or complex compounds.

The carbon thermal reduction can adopt conductive carbon materials, organic binders and additional carbon materials contained in the waste lithium ion battery materials, and has the defect that the sublimation loss of lithium oxide in the high-temperature reduction process at the temperature of over 600 ℃ causes the lithium recovery rate not to reach the 85 percent lithium recovery rate specified by the industry standard.

The patent discloses that a plurality of strong chemical reducing agents represented by sulfide, sulfite, hydrogen peroxide, hydrazine hydrate, hydrogen, saccharides and organic acid can reduce high-valence cobalt nickel manganese oxide in waste ternary lithium ion battery materials into soluble or leachable low-valence cobalt nickel manganese metal salt at a relatively low temperature, but the technology economy and the safety and environmental protection still have a space for improving the technology economy and the environmental protection.

Disclosure of Invention

The invention aims to provide a method for preparing a lithium ion sieve by taking a waste lithium ion battery material as a raw material, in particular to a method for preparing a manganese lithium ion sieve by electrolyzing, reducing and leaching metal elements in a positive electrode material of a waste ternary lithium ion battery in a 0.2-0.5mol/L sulfuric acid solution and simultaneously electrolyzing, oxidizing and recovering manganese dioxide, wherein a titanium blue cathode is selected in electrolysis, the titanium blue is coated by a terylene filter cloth bag, and a cobalt nickel lithium manganate positive electrode material separated from the waste ternary lithium ion battery is filled in the titanium blue cathode; the anode of a titanium plate is selected in the electrolysis, and the temperature of the electrolyte is 90 DEGAnode current density 40-80A/m at-100 deg.C²The method comprises the following specific operation steps:

(1) filling waste ternary lithium ion battery cobalt nickel lithium manganate material powder into cathode titanium blue coated by a polyester filter bag, and putting the cathode titanium blue and the polyester filter bag into an electrolytic cell; placing the titanium plate anode into an electrolytic tank, adding 0.2-0.5mol/L sulfuric acid as electrolyte, introducing direct current to start electrolysis at the temperature of 90-100 ℃, and controlling the current density of the anode to be 40-80A/m²；

(2) Electrolyzing and reducing high-valence cobalt nickel lithium manganate powder in a titanium blue cathode in sulfuric acid electrolyte to generate low-valence cobalt sulfate, nickel sulfate, manganese sulfate and lithium sulfate, dissolving the low-valence cobalt sulfate, nickel sulfate, manganese sulfate and lithium sulfate in the sulfuric acid electrolyte, electrolytically oxidizing the manganese sulfate in the electrolyte on the surface of a titanium plate anode to generate manganese dioxide, continuously plating the manganese dioxide on the surface of the titanium plate anode, and stopping electrolysis and supplementing the cobalt nickel lithium manganate material powder after most of the cobalt nickel lithium manganate material powder in the titanium blue cathode is dissolved;

(3) when the thickness of the electrolytic manganese dioxide coating reaches, the electrolytic manganese dioxide coating is stripped from the titanium plate electrode, so that manganese salt is separated from cobalt nickel sulfate, and the cobalt nickel sulfate in the electrolyte cannot be oxidized and deposited or reduced and deposited under the electrolytic condition;

(4) crushing an electrolytic manganese dioxide coating stripped from a titanium plate electrode, washing with water to deacidify, mixing and grinding with lithium hydroxide, controlling the molar ratio of Li to Mn to be 0.8-1.2, and roasting at the temperature of 450-550 ℃ for 2-6h to form a manganese-series lithium ion sieve precursor Li_1.33Mn_1.67O₄；

(5) Loading the manganese-based lithium ion sieve precursor into a titanium blue anode, coating the titanium blue with a terylene filter cloth bag, immersing the titanium blue into a sulfuric acid solution of 0.2-0.5mol/L, taking a titanium plate as a cathode, and performing current density at the anode of 40-80A/m²Electrolytic oxidation is carried out to completely oxidize unstable trivalent manganese in the manganese-based lithium ion sieve into tetravalent manganese, and simultaneously sulfuric acid electrolyte enables precursor Li of the manganese-based lithium ion sieve_1.33Mn_1.67O₄Desorbing lithium ions;

(6) removing lithium from manganese series lithium ion sieve precursorRemoving the blue, washing with deionized water, and drying at the temperature of 100-₂﹒0.5H₂Manganese-based lithium ion sieve of O;

(7) the manganese-based lithium ion sieve is immersed into 0.5g/L lithium chloride aqueous solution, the lithium adsorption capacity is measured to be 45-50mg/g, and the dissolution loss rate of the manganese-based lithium ion sieve after 10 times of adsorption and desorption circulation is 0.5-0.9%.

The preparation method of the electrolytic manganese dioxide comprises two processes of high-temperature low-current density electrolysis and room-temperature high-current density electrolysis. Manganese dioxide generated by high-temperature low-current density electrolysis is usually plated on the surface of the titanium anode and is easier to recover; manganese dioxide produced by high current density electrolysis at room temperature is typically suspended in the electrolyte. The invention adopts a high-temperature low-current density electrolysis mode with mature process and lower power consumption to prevent the titanium blue anode from being passivated under high current density.

In the invention, the high-valence cobalt nickel manganese oxide in the cathode blue is reduced into low-valence cobalt nickel manganese oxide, and is further efficiently leached by sulfuric acid in electrolyte to form soluble cobalt nickel manganese lithium sulfate.

The conductive carbon material mixed in the cobalt-nickel-manganese oxide anode material with high valence state continuously plays a conductive role in the electrolytic reduction process, the cathode efficiency of the electrolytic reduction is improved, and the conductive carbon material is remained in the cathode titanium blue coated by the terylene filter cloth bag after the electrolysis is finished and can be recycled after being separated from the metal oxide.

In the invention, unstable trivalent manganese in the manganese lithium ion sieve is completely converted into tetravalent manganese through electrolytic oxidation treatment, so that the dissolution loss of the trivalent manganese in a disproportionation reaction in a dilute acid solution is avoided; simultaneously, sulfuric acid electrolyte enables manganese lithium ion sieve precursor Li_1.33Mn_1.67O₄The lithium ions in (1) are desorbed.

In the invention, the electrolyte after electrolytic oxidation separation of manganese salt is neutralized by sodium carbonate aqueous solution, and then lithium salt is recovered by a lithium ion sieve adsorption method, the lithium recovery rate can reach 95 percent and far exceeds the specified value of the industrial standard of 85 percent; and further adding a sodium carbonate aqueous solution into the electrolyte, and precipitating and separating to recover cobalt salt and nickel salt step by step, wherein the recovery rate of cobalt, nickel and manganese metal can reach 98% of the specified value of the industry standard.

The manganese-based lithium ion sieve precursor with a spinel structure comprises LiMn₂O₄、Li_1.33Mn_1.67O₄And Li_1.6Mn_1.6O₄In various forms, the Li/Mn ratios are 0.5, 0.8 and 1.0, respectively. As the Li/Mn ratio is increased, the theoretical adsorption capacity of the lithium ion sieve is increased to 38mg/g, 56mg/g and 68mg/g respectively, but the molecular structure stability is reduced, and the dissolution loss of manganese is increased when lithium is eluted by acid. Selective synthesis of Li in the invention_1.33Mn_1.67O₄The manganese-based lithium ion sieve precursor is subjected to electrolytic oxidation treatment, so that a small amount of trivalent manganese in the manganese-based lithium ion sieve precursor is converted into tetravalent manganese, and the lithium adsorption capacity and the stability of the manganese-based lithium ion sieve are optimal.

Compared with the prior wet reduction leaching technology, the method for leaching the anode material of the waste ternary lithium ion battery by electrolytic reduction has higher reduction leaching efficiency, avoids the large consumption of chemical reducing agents, and is a clean production process.

In the invention, manganese dioxide is separated from the leaching solution of the anode material of the waste ternary lithium ion battery by adopting electrolytic oxidation, so that the problem of high-efficiency separation of manganese salt and cobalt-nickel lithium salt is solved.

The titanium blue electrode used in the invention is formed by processing a titanium mesh, and the surface of the titanium mesh is passivated, so that the electrochemical reaction is mainly carried out on the surface of a conductive material filled in the titanium mesh.

The experimental raw material, namely the waste ternary lithium ion battery positive material, is an industrial product purchased on the internet or obtained by self-disassembling the waste ternary lithium ion battery, and lithium hydroxide, hydrochloric acid and lithium chloride are all commercially available chemical pure reagents.

The invention has the beneficial effects that:

(1) the electrolytic reduction of the ternary lithium ion battery anode material and the separation and recovery of the electrolytic oxidized manganese dioxide are jointly applied, so that the current efficiency is improved by times, and the technical economy of the process is improved;

(2) the manganese-based lithium ion sieve is subjected to electrolytic oxidation treatment to convert unstable trivalent manganese into tetravalent manganese, so that manganese dissolution loss does not occur in a dilute acid solution, and the cycle service life of the manganese-based lithium ion sieve is greatly prolonged.

Detailed Description

Example 1

100g of waste ternary lithium ion battery cobalt nickel lithium manganate material powder is filled in cathode titanium blue coated by a terylene filter bag, and the cathode titanium blue and the terylene filter bag are placed in an electrolytic cell; placing the titanium plate anode into an electrolytic tank, adding 0.5mol/L sulfuric acid as electrolyte, introducing direct current 4A to start electrolysis at the temperature of 90-100 ℃, and controlling the current density of the anode to be 40A/m². High-valence cobalt nickel lithium manganate powder in the titanium blue cathode is electrolytically reduced in sulfuric acid electrolyte to generate low-valence cobalt sulfate, nickel sulfate, manganese sulfate and lithium sulfate, and the low-valence cobalt sulfate, nickel sulfate, manganese sulfate and lithium sulfate are dissolved in the sulfuric acid electrolyte, and the manganese sulfate in the electrolyte is electrolytically oxidized on the surface of the titanium plate anode to generate manganese dioxide, and the manganese dioxide is continuously plated on the surface of the titanium plate anode. And after electrolyzing for 10 hours, stopping electrolyzing and supplementing the cobalt nickel lithium manganate material powder after most of the cobalt nickel lithium manganate material powder in the cathode titanium blue is dissolved.

The electrolytic manganese dioxide plating layer was peeled off from the titanium plate electrode, pulverized, washed with water to deacidify, and dried to obtain 24.9g (0.29 mol) of electrolytic manganese dioxide. Mixing and grinding the mixture with 6.9g (0.29 mol) of lithium hydroxide, and then roasting the mixture for 2 hours at 500 ℃ to form a manganese-series lithium ion sieve precursor Li_1.33Mn_1.67O₄. Loading a manganese-based lithium ion sieve precursor into a titanium blue anode, coating the titanium blue with a terylene filter cloth bag, immersing the titanium blue into a 0.5mol/L sulfuric acid solution, introducing direct current 4A by taking a titanium plate as a cathode, and controlling the current density of the anode to be 40A/m²Then electrolytic oxidation is carried out for 1.5h, unstable trivalent manganese in the manganese-based lithium ion sieve is completely oxidized and converted into tetravalent manganese, and meanwhile sulfuric acid electrolyte enables precursor Li of the manganese-based lithium ion sieve_1.33Mn_1.67O₄The lithium ions in (1) are desorbed.

Removing lithium from the manganese-based lithium ion sieve precursor, removing the lithium from titanium blue, cleaning the lithium ion sieve precursor by using deionized water, and drying the lithium ion sieve precursor at the temperature of 100-₂﹒0.5H₂27.5g of manganese-based lithium ion sieve for O. 10g of a manganese-based lithium ion sieve was immersed in a 0.5g/L aqueous solution of lithium chloride, and the lithium adsorption capacity was found to be 50mg/g, the dissolution loss rate of the manganese lithium ion sieve after 10 times of adsorption and desorption circulation is 0.5 percent.

Example 2

100g of waste ternary lithium ion battery cobalt nickel lithium manganate material powder is filled in cathode titanium blue coated by a terylene filter bag, and the cathode titanium blue and the terylene filter bag are placed in an electrolytic cell; placing the titanium plate anode into an electrolytic tank, adding 0.5mol/L sulfuric acid as electrolyte, introducing direct current 8A to start electrolysis at the temperature of 90-100 ℃, and controlling the current density of the anode to be 80A/m². High-valence cobalt nickel lithium manganate powder in the titanium blue cathode is electrolytically reduced in sulfuric acid electrolyte to generate low-valence cobalt sulfate, nickel sulfate, manganese sulfate and lithium sulfate, and the low-valence cobalt sulfate, nickel sulfate, manganese sulfate and lithium sulfate are dissolved in the sulfuric acid electrolyte, and the manganese sulfate in the electrolyte is electrolytically oxidized on the surface of the titanium plate anode to generate manganese dioxide, and the manganese dioxide is continuously plated on the surface of the titanium plate anode. And after most of the cobalt nickel lithium manganate material powder in the cathode titanium blue is dissolved after 6 hours of electrolysis, stopping electrolysis and supplementing the cobalt nickel lithium manganate material powder.

The electrolytic manganese dioxide plating layer was peeled off from the titanium plate electrode, pulverized, washed with water to deacidify, and dried to obtain 24.1g (0.28 mol) of electrolytic manganese dioxide. Mixing and grinding the mixture with 5.5g (0.23 mol) of lithium hydroxide, and then roasting the mixture for 2 hours at 500 ℃ to form a manganese-series lithium ion sieve precursor Li_1.33Mn_1.67O₄. Loading a manganese-based lithium ion sieve precursor into a titanium blue anode, coating the titanium blue with a terylene filter cloth bag, immersing the titanium blue into a 0.5mol/L sulfuric acid solution, introducing direct current 8A by taking a titanium plate as a cathode, and controlling the current density of the anode to be 80A/m²Electrolytic oxidation is carried out for 0.5 h to ensure that unstable trivalent manganese in the manganese-based lithium ion sieve is completely oxidized and converted into tetravalent manganese, and meanwhile, sulfuric acid electrolyte ensures that a precursor Li of the manganese-based lithium ion sieve_1.33Mn_1.67O₄The lithium ions in (1) are desorbed.

Removing lithium from the manganese-based lithium ion sieve precursor, removing the lithium from titanium blue, cleaning the lithium ion sieve precursor by using deionized water, and drying the lithium ion sieve precursor at the temperature of 100 ℃ to obtain the manganese dioxide with the chemical composition of MnO₂﹒0.5H₂26.5g of manganese-based lithium ion sieve for O. 10g of manganese lithium ion sieve is immersed into 0.5g/L lithium chloride aqueous solution, the lithium adsorption capacity is measured to be 45mg/g, and after 10 times of adsorption and desorption cycle, manganese lithium ion is carried outThe dissolution loss rate of the sub-sieve is 0.9%.