Method for preparing carbon-based lithium ion sieve by using waste lithium ion battery as raw material
阅读说明：本技术 一种废旧锂离子电池为原料制备碳基锂离子筛的方法 (Method for preparing carbon-based lithium ion sieve by using waste lithium ion battery as raw material ) 是由 李建生 袁永顺 韩璐 周蕾 李璐 王雪 刘炳光 周素花 马晓宝 王晨 刘红斌 于 2021-08-02 设计创作，主要内容包括：本发明涉及一种废旧锂离子电池为原料制备碳基锂离子筛的方法,特别是以废旧三元锂离子电池负极材料作为锂源,废旧三元锂离子电池正极材料作为锰源,通过电解氧化将二氧化锰镀覆在含锂盐的负极碳材料上,后处理得到化学组成为MnO-(2)﹒0.5H-(2)O﹒x C的碳基锰系锂离子筛,其中,x=5-20,其锂吸附容量为15-30mg/g,吸脱附循环10次后锂离子筛的锰溶损率为0.4%-0.8%。本发明利用废旧三元锂离子电池正极材料中低价值的锰和负极材料中难以回收的锂综合利用制备了高附加值的碳基锰系锂离子筛。本发明中废旧三元锂离子电池正极材料电解还原浸取和二氧化锰电解氧化镀覆同时进行,使电流效率成倍提高。(The invention relates to a method for preparing a carbon-based lithium ion sieve by taking a waste lithium ion battery as a raw material, in particular to a method for preparing a carbon-based lithium ion sieve by taking a negative electrode material of a waste ternary lithium ion battery as a lithium source and a positive electrode material of the waste ternary lithium ion battery as a manganese source, plating manganese dioxide on a negative electrode carbon material containing lithium salt through electrolytic oxidation, and performing post-treatment to obtain a material with a chemical composition of MnO 2 ﹒0.5H 2 And the carbon-based manganese-based lithium ion sieve with the O & lt x C & gt value, wherein x =5-20, the lithium adsorption capacity is 15-30mg/g, and the manganese dissolution loss rate of the lithium ion sieve after 10 times of adsorption and desorption cycles is 0.4% -0.8%. The invention prepares the carbon-based manganese lithium ion sieve with high added value by comprehensively utilizing low-value manganese in the anode material of the waste ternary lithium ion battery and lithium which is difficult to recover in the cathode material. The anode material of the waste ternary lithium ion battery is electrolyzed and reducedThe leaching and the manganese dioxide electrolytic oxidation plating are carried out simultaneously, so that the current efficiency is improved by times.)
1. A method for preparing a carbon-based lithium ion sieve by taking a waste lithium ion battery as a raw material is characterized in that a negative electrode material of the waste ternary lithium ion battery is taken as a lithium source, a positive electrode material of the waste ternary lithium ion battery is taken as a manganese source, manganese dioxide is plated on a negative electrode carbon material containing lithium salt through electrolytic oxidation, and the carbon-based manganese lithium ion sieve is obtained through further post-treatment, wherein the preparation process comprises the following 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; filling lithium-containing carbon material powder separated from waste ternary lithium ion batteries into anode titanium blue coated by a polyester filter bag, and putting the anode titanium blue and the polyester filter bag into an electrolytic tank; adding 0.2-0.5mol/L sulfuric acid as electrolyte at 90-100 deg.C, introducing DC to start electrolysis, and controlling anode current density at 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 lithium-containing carbon material in a titanium blue anode to generate manganese dioxide, continuously plating the manganese dioxide on the surface of the carbon material, and stopping electrolysis when the molar ratio of Li to Mn in the lithium-containing carbon material reaches 0.85-1.1;
(3) washing the lithium-containing carbon material coated with manganese dioxide in the titanium blue anode by deionized water, placing the lithium-containing carbon material in a drying oven by using a ceramic crucible, drying the lithium-containing carbon material at the temperature of 110-; in the process, part of the carbon material is oxidized and decomposed, and the manganese dioxide coated on the surface of the carbon material retards the high-temperature sublimation loss of lithium oxide in the carbon material, so that the lithium oxide is completely converted into lithium manganese oxide, and the effective utilization rate of lithium salt is improved;
(4) filling the roasted carbon-based manganese-based lithium ion sieve precursor into anode titanium blue coated by a terylene filter bag, and putting the anode titanium blue and the terylene filter bag into an electrolytic cell; 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; adding 0.2-0.5mol/L sulfuric acid as electrolyte, introducing direct current to start electrolysis at 90-100 deg.C, and controlling anode current density to 40-80A/m2(ii) a Unstable trivalent manganese in the manganese-based lithium ion sieve is completely converted into tetravalent manganese so as to avoid the dissolution loss of the trivalent manganese in a disproportionation reaction in a dilute acid solution; simultaneously, the sulfuric acid electrolyte enables lithium ions in the precursor of the carbon-based manganese lithium ion sieve to be desorbed;
(5) removing the precursor of the carbon-based manganese-based lithium ion sieve subjected to electrolytic oxidation and lithium removal from the anode titanium blue, cleaning with deionized water, and drying at the temperature of 100-2﹒0.5H2Carbon-based manganese-based lithium ion sieve having an O £ x C, wherein, x = 5-20;
(6) the carbon-based manganese lithium ion sieve is immersed into 0.5g/L lithium chloride aqueous solution, the lithium adsorption capacity is 15-30mg/g, and the dissolution loss rate of the lithium ion sieve after 10 times of adsorption and desorption cycles is 0.4-0.8%.
Technical Field
The invention relates to a method for preparing a carbon-based lithium ion sieve by taking a waste lithium ion battery as a raw material, in particular to a method for preparing a carbon-based manganese-based lithium ion sieve by taking a negative electrode material of a waste ternary lithium ion battery as a lithium source and taking a positive electrode material of the waste ternary lithium ion battery as a manganese source, belonging to the field of chemical industry and new energy materials.
Technical Field
The lithium ion battery mainly comprises an anode, a cathode, organic electrolyte and a terylene filter, wherein 97 percent of cathode active materials are graphite. During the first charge and discharge process of the lithium ion battery, the negative electrode material and the electrolyte react at a solid-liquid interface, a solid electrolyte interface film (SEI) containing lithium salt is generated on the surface of the negative electrode material, and the SEI film contains Li2CO3 、ROCOOLi、CH3Oli and Li2And lithium salts such as O. During the working process of the lithium ion battery, when the lithium ions are inserted in/out of the positive electrode and the negative electrode to exchange energy, part of the lithium ions are inserted into the mesopores of the negative electrode material, so that a certain amount of lithium is collected in the negative electrode material of the abandoned lithium ion battery. Due to reduction and deposition of electrolyte, the content of lithium in the carbon material powder of the negative electrode of the waste lithium ion battery reaches up to 31 mg/g, which is obviously higher than the content of lithium in common lithium ore and brine.
The current research and development for recycling waste lithium ion batteries focuses on the separation and recovery of cobalt, nickel, lithium, copper and aluminum, and the separation and recovery of a large amount of residual negative graphite carbon powder is not paid enough attention for a long time. Therefore, it is very meaningful to utilize the lithium salt in the negative electrode material of the waste lithium ion battery.
The literature reports a method for recovering lithium salt in a negative electrode carbon material of a waste lithium ion battery by complex leaching of hydrochloric acid, sulfuric acid, sulfamic acid, citric acid and sulfuric acid/hydrogen peroxide. Because the negative electrode carbon material directly stripped from the waste lithium ion battery negative electrode slice contains a certain amount of organic electrolyte, adhesive and the like, the substances are difficult to dissolve in an acidic aqueous solution, lithium salt in the negative electrode carbon material can be completely leached only by calcining the substances at high temperature, and the actual recovery process for recovering the lithium salt from the negative electrode carbon material is relatively complicated.
Zhouyang et al, in Chinese patent 112216894A (2021-01-12.), disclose that metal elements in waste lithium ion batteries are leached and separated by sulfuric acid and hydrogen peroxide, electrode graphite powder is used as a carrier of a lithium ion sieve, manganese salt and lithium salt solution are adsorbed on the electrode graphite powder, and the electrode graphite powder is dried and then is roasted at a high temperature of 600 ℃ in a form of 300-plus-one, so as to prepare the manganese-series lithium ion sieve loaded by the graphite powder, and the manganese-series lithium ion sieve is applied to selective adsorption of lithium ions in a leaching solution of a ternary lithium ion battery material, so that a good effect is obtained, the lithium adsorption capacity reaches 20.7-25.2mg/g, the manganese dissolution rate of 10 times of cycle of adsorption and desorption is less than 1%, but lithium salt is required to be separated and recovered firstly, and the process is relatively complex. Particularly, the manganese-based lithium ion sieve precursor prepared in the presence of a carbon material is easily reduced by carbon heat to generate unstable trivalent manganese salt impurities, so that the cycle service life of the manganese-based lithium ion sieve is shortened.
The method for preparing the lithium ion sieve by using the waste lithium ion battery as the raw material has the advantages of excellent performance and technical and economic advantages, 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 from industrial raw materials, is applied to extracting lithium from waste lithium ion battery materials, extracting lithium from salt lake brine 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.
In the preparation process of preparing the manganese-based lithium ion sieve by taking the lithium ion battery as a raw material, the process of generating lithium manganate through the high-temperature reaction of manganese salt and lithium salt is generally carried out, the sublimation loss of lithium oxide is serious at the temperature of over 600 ℃, the difference between the Li/Mn molar ratio of the raw material and the Li/Mn molar ratio in a manganese-based lithium ion sieve precursor is large, the process is difficult to control, the production cost is high, and the process technology and the safety and environmental protection have a space for improving and promoting greatly.
Disclosure of Invention
The invention aims to provide a method for preparing a carbon-based lithium ion sieve by using a waste lithium ion battery as a raw material, in particular to a method for preparing the carbon-based lithium ion sieve by taking a negative electrode material of the waste ternary lithium ion battery as a lithium source and a positive electrode material of the waste ternary lithium ion battery as a manganese source, plating manganese dioxide on a negative electrode carbon material containing lithium salt through electrolytic oxidation and further carrying out post-treatment to obtain the carbon-based manganese lithium ion sieve, wherein the preparation process comprises the following 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; filling lithium-containing carbon material powder separated from waste ternary lithium ion batteries into anode titanium blue coated by a polyester filter bag, and putting the anode titanium blue and the polyester filter bag into an electrolytic tank; adding 0.2-0.5mol/L sulfuric acid as electrolyte at 90-100 deg.C, introducing DC to start electrolysis, and controlling anode current density at 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 lithium-containing carbon material in a titanium blue anode to generate manganese dioxide, continuously plating the manganese dioxide on the surface of the carbon material, and stopping electrolysis when the molar ratio of Li to Mn in the lithium-containing carbon material reaches 0.85-1.1;
(3) washing the lithium-containing carbon material coated with manganese dioxide in the titanium blue anode by deionized water, placing the lithium-containing carbon material in a drying oven by using a ceramic crucible, drying the lithium-containing carbon material at the temperature of 110-; in the process, part of the carbon material is oxidized and decomposed, and the manganese dioxide coated on the surface of the carbon material retards the high-temperature sublimation loss of lithium oxide in the carbon material, so that the lithium oxide is completely converted into lithium manganese oxide, and the effective utilization rate of lithium salt is improved;
(4) filling the roasted carbon-based manganese-based lithium ion sieve precursor into anode titanium blue coated by a terylene filter bag, and filling the anode titanium blue and the terylene filter bagPutting the nylon filter bag into an electrolytic bath; 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; adding 0.2-0.5mol/L sulfuric acid as electrolyte, introducing direct current to start electrolysis at 90-100 deg.C, and controlling anode current density to 40-80A/m2(ii) a Unstable trivalent manganese in the manganese-based lithium ion sieve is completely converted into tetravalent manganese so as to avoid the dissolution loss of the trivalent manganese in a disproportionation reaction in a dilute acid solution; simultaneously, the sulfuric acid electrolyte enables lithium ions in the precursor of the carbon-based manganese lithium ion sieve to be desorbed;
(5) removing the precursor of the carbon-based manganese-based lithium ion sieve subjected to electrolytic oxidation and lithium removal from the anode titanium blue, cleaning with deionized water, and drying at the temperature of 100-2﹒0.5H2Carbon-based manganese-based lithium ion sieve having an O £ x C, wherein, x = 5-20;
(6) the carbon-based manganese lithium ion sieve is immersed into 0.5g/L lithium chloride aqueous solution, the lithium adsorption capacity is 15-30mg/g, and the dissolution loss rate of the lithium ion sieve after 10 times of adsorption and desorption cycles is 0.4-0.8%.
The lithium source in the invention is native in the cathode material of the waste lithium ion battery, no external additional lithium source is needed, the manganese dioxide is directly plated by electrolytic oxidation after the lithium content in the cathode material is measured, and the complex separation and recovery process of the lithium salt in the cathode material is not needed.
The manganese source in the invention is native in the anode material of the waste ternary lithium ion battery, and is the comprehensive utilization of low-value manganese byproducts in the process of extracting cobalt, nickel and lithium from the anode material of the waste lithium ion battery. After the manganese salt is separated by electrolyzing the anode material of the waste ternary lithium ion battery, the cobalt, the nickel and the lithium salt can be conveniently and efficiently recycled from the electrolyte.
The anode material of the waste ternary lithium ion battery is a mixture of high-valence cobalt nickel manganese oxide and a conductive carbon material, the mixed conductive carbon material continuously plays a conductive role in the electrolytic reduction process, the cathode current of titanium blue is transferred to the high-valence cobalt nickel manganese oxide, the conductive carbon material improves the cathode efficiency of the electrolytic reduction, and the conductive carbon material is left in the cathode titanium blue coated by the terylene filter bag after the electrolysis is finished and can be further recycled after being separated from the metal oxide.
The electrolyte after the electrolytic oxidation separation of manganese salt is neutralized by sodium carbonate aqueous solution, and cobalt salt and nickel salt are separated and recovered by fractional precipitation separation, wherein the recovery rate of cobalt, nickel and manganese metal can reach 98% specified value of industry standard; and then, lithium salt is recovered by a lithium ion sieve adsorption method or a precipitation method, the lithium recovery rate can reach 95 percent, and the specified value far exceeds the industrial specification is 85 percent.
The manganese-based lithium ion sieve precursor comprises LiMn2O4、Li1.33Mn1.67O4And Li1.6Mn1.6O4Forms having Li/Mn ratios of 0.5, 0.8 and 1.0, respectively. Selective synthesis of Li in the invention1.33Mn1.67O4Molecular composition of MnO of x C carbon-based manganese-based lithium ion sieve precursor after delithiation to form carbon-based manganese-based lithium ion sieve2﹒0.5H2O £ x C, where x = 5-20.
According to the invention, the carbon material with conductivity is used as the lithium ion sieve carrier, so that the manganese-based lithium ion sieve is endowed with conductivity and can be subjected to electrolytic oxidation, trivalent manganese in the manganese-based lithium ion sieve is oxidized into tetravalent manganese, the stability of the manganese-based lithium ion sieve is improved, the dissolution loss rate of manganese in the acid washing desorption process of the lithium ion sieve is greatly reduced, and the cycle service life of the carbon-based manganese-based lithium ion sieve is prolonged.
According to the invention, the carbon material with high specific surface area is used as the lithium ion sieve carrier, so that the specific surface area of the carbon-based manganese lithium ion sieve is enlarged, the carbon-based manganese lithium ion sieve is easy to process and form into the industrial carbon-based manganese lithium ion sieve filler, and the lithium adsorption capacity and the adsorption and desorption speed of the carbon-based manganese lithium ion sieve are improved.
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 blue electrode, and the manganese dioxide is prevented from being oxidized and deposited on the titanium blue.
The experimental raw materials of the anode material and the cathode carbon material of the waste ternary lithium ion battery are commercial industrial products or the sulfuric acid and the lithium chloride obtained by self-disassembling the waste ternary lithium ion battery are commercially available chemical pure reagents.
The invention has the beneficial effects that:
(1) according to the invention, the high-added-value carbon-based manganese lithium ion sieve is prepared by comprehensively utilizing low-value manganese in the anode material and lithium which is difficult to recover in the cathode material of the waste ternary lithium ion battery;
(2) in the invention, the anode material of the waste ternary lithium ion battery is subjected to electrolytic reduction leaching, so that the large consumption of chemical reducing agents is avoided, convenience is provided for the subsequent recovery of valuable cobalt nickel lithium metal, and the recovery cost is reduced;
(3) according to the invention, the electrolytic reduction leaching and electrolytic oxidation plating of manganese dioxide on the anode material of the waste ternary lithium ion battery are carried out simultaneously, so that the current efficiency is improved by times, and the technical economy of the process is improved.
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; 20g (containing 0.03g/g lithium) of lithium-containing carbon material powder separated from the waste ternary lithium ion battery is filled in an anode titanium blue coated by a terylene filter bag, and the anode titanium blue and the terylene filter bag are put in an electrolytic cell; adding 0.2mol/L sulfuric acid as electrolyte at 90-100 deg.C, introducing direct current 4A to start electrolysis, and making anode current density 40A/m2. Manganese sulfate in the electrolyte is electrolyzed and oxidized on the surface of the lithium-containing carbon material in the titanium blue anode to generate manganese dioxide, and the manganese dioxide is continuously plated on the surface of the carbon material, and the electrolysis is stopped after 5 hours of electrolysis.
Washing the lithium-containing carbon material coated with manganese dioxide in the titanium blue anode by deionized water, placing the lithium-containing carbon material in a drying oven by using a ceramic crucible, drying the lithium-containing carbon material at the temperature of 110-120 ℃, then roasting the dried material in a high-temperature furnace at the temperature of 700 ℃ for 1 hour, and carrying out thermochemical reaction on lithium salt and manganese dioxide to form a precursor of the carbon-based manganese-based lithium ion sieve. Filling the roasted carbon-based manganese-based lithium ion sieve precursor into anode titanium blue coated by a terylene filter bag, and putting the anode titanium blue and the terylene filter bag into an electrolytic cell; waste ternary lithium ion battery cobalt nickel lithium manganate materialFilling the 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; adding 0.5mol/L sulfuric acid as electrolyte, introducing direct current 4A to start electrolysis at 90-100 deg.C, and controlling anode current density to 40A/m2(ii) a And stopping electrolysis after 0.5h of electrolysis, so that unstable trivalent manganese in the manganese-based lithium ion sieve is completely converted into tetravalent manganese, and simultaneously, the sulfuric acid electrolyte enables lithium ions in the precursor of the carbon-based manganese-based lithium ion sieve to be desorbed. Removing the precursor of the carbon-based manganese-based lithium ion sieve subjected to electrolytic oxidation and lithium removal treatment from the anode titanium blue, cleaning with deionized water, and drying at the temperature of 100-2﹒0.5H2Lithium ion sieve based on carbon-based manganese with O.sub.8.2 C.19.7 g. The carbon-based manganese-based lithium ion sieve is immersed in 0.5g/L lithium chloride aqueous solution, the lithium adsorption capacity is 25.5mg/g, and the manganese dissolution loss rate of the lithium ion sieve after 10 times of adsorption and desorption cycles is 0.4%.
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; 40g (containing 0.03g/g lithium) of lithium-containing carbon material powder separated from the waste ternary lithium ion battery is filled in an anode titanium blue coated by a terylene filter bag, and the anode titanium blue and the terylene filter bag are put in an electrolytic cell; adding 0.5mol/L sulfuric acid as electrolyte, introducing direct current 8A to start electrolysis at the electrolyte temperature of 90-100 ℃, and enabling the anode current density to be 80A/m2. Manganese sulfate in the electrolyte is electrolyzed and oxidized on the surface of the lithium-containing carbon material in the titanium blue anode to generate manganese dioxide, and the manganese dioxide is continuously plated on the surface of the carbon material, and the electrolysis is stopped after 2 hours of electrolysis.
Washing the lithium-containing carbon material coated with manganese dioxide in the titanium blue anode by deionized water, placing the lithium-containing carbon material in a drying oven by using a ceramic crucible, drying the lithium-containing carbon material at the temperature of 110-120 ℃, then roasting the dried material in a high-temperature furnace at the temperature of 700 ℃ for 1 hour, and carrying out thermochemical reaction on lithium salt and manganese dioxide to form a precursor of the carbon-based manganese-based lithium ion sieve. Filling the roasted carbon-based manganese-based lithium ion sieve precursor into anode titanium blue coated by a terylene filter bag, and putting the anode titanium blue and the terylene filter bag into an electrolytic cell; waste ternary lithium ion battery cobaltFilling lithium nickel manganese oxide 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; adding 0.5mol/L sulfuric acid as electrolyte, introducing direct current 8A to start electrolysis at 90-100 deg.C, and controlling anode current density at 80A/m2(ii) a And stopping electrolysis after 0.3h of electrolysis, so that unstable trivalent manganese in the manganese-based lithium ion sieve is completely converted into tetravalent manganese, and simultaneously, the sulfuric acid electrolyte enables lithium ions in the precursor of the carbon-based manganese-based lithium ion sieve to be desorbed. Removing the precursor of the carbon-based manganese-based lithium ion sieve subjected to electrolytic oxidation and lithium removal treatment from the anode titanium blue, cleaning with deionized water, and drying at the temperature of 100-2﹒0.5H244g of carbon-based manganese-based lithium ion sieve having an O.sub.15.4C. The carbon-based manganese-based lithium ion sieve is immersed in 0.5g/L lithium chloride aqueous solution, the lithium adsorption capacity is measured to be 18.1mg/g, and the manganese dissolution loss rate of the lithium ion sieve after 10 times of adsorption and desorption cycles is 0.8%.
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