Method for selectively leaching metal of waste lithium battery material based on irradiation activation

Abstract

The invention discloses a method for selectively leaching metal in a waste lithium battery material based on irradiation activation, which is characterized in that the waste lithium battery material is dispersed into an aqueous solution containing an oxidizing agent, and the metal in the material can be leached under a certain irradiation dose without adding a catalyst. The method for efficiently recovering the metal from the waste lithium battery has the advantages of being mild in process, environmentally friendly, convenient to operate, high in efficiency and the like, strong acid, strong alkali and volatile organic solvents are not used in the whole reaction process, the reaction period is short to the minute level, and the method has excellent engineering amplification potential and industrialization prospects and is suitable for industrial production. The method is expected to play an important role in the fields of environmental protection and resource circulation, and a feasible technical support is provided for constructing a low-carbon, environment-friendly and resource-saving green economic system.

Description

Technical Field

[0001] This invention relates to the fields of irradiation technology, advanced oxidation technology, and metal recycling, and specifically to a method for selectively leaching metals from waste lithium battery materials based on irradiation activation. Background Technology

[0002] Retired batteries contain strategically valuable metals such as nickel, cobalt, and manganese. Failure to recycle them efficiently will not only result in the loss of these scarce resources, but the organic electrolytes and fluorinated electrolytes they contain may also pose environmental risks. Therefore, promoting the recycling of retired batteries and the resource utilization of strategic metals has become a crucial link in achieving a circular economy and ensuring resource security.

[0003] Currently, mainstream processes follow a three-stage resource recovery process: pretreatment, metal extraction, and material regeneration, aiming to achieve closed-loop recycling of key mineral resources. In the core metal extraction stage, the industry has differentiated and formed three technical routes: physical methods, hydrometallurgy, and pyrometallurgy. Hydrometallurgy, as the mainstream recovery technology, plays a core role in realizing the recycling of key mineral resources due to its advantages of high recovery rates and high purity for valuable metals such as cobalt, nickel, and manganese. However, traditional hydrometallurgical processes still face significant challenges: the leaching process typically relies on high temperatures and high acid concentrations, resulting in high reaction energy consumption, large reagent consumption, slow leaching kinetics, and heavy subsequent wastewater treatment load and significant environmental risks. Therefore, developing efficient, clean, and low-energy-consumption new leaching technologies is crucial to improving the overall efficiency of lithium battery resource recovery.

[0004] Advanced oxidation technologies, due to their ability to generate strong oxidizing free radicals in situ, have been widely used in the treatment of recalcitrant organic matter. However, systematic research on their application in metal leaching is still insufficient. Theoretically, this technology can effectively disrupt the structure of battery cathode materials and accelerate metal dissolution through the strong oxidizing effect of free radicals, potentially replacing or reducing the amount of traditional acids and reducing agents. However, using oxidants alone often results in limited activation efficiency and demanding reaction conditions, making it difficult to achieve efficient metal leaching under mild conditions.

[0005] Irradiation technologies (such as X-ray, gamma-ray, and electron beam irradiation) have been proven to be highly efficient physical enhancement methods, effectively promoting oxidant activation, increasing free radical yield, and enhancing mass transfer and reaction kinetics. Combining irradiation technology with advanced oxidation processes for the recovery of valuable metals from lithium-ion batteries in inorganic solution systems holds promise for generating a large number of active species through irradiation activation of oxidants in near-neutral or weakly acidic environments, thereby efficiently deconstructing battery cathode materials and releasing target metal ions. This method not only helps reduce the dependence of traditional recycling processes on strong acids and chemical reagents but also reduces the risk of secondary pollution. However, current research on this composite system is insufficient and requires further in-depth exploration. Notably, through rapid kinetic control, this system can significantly shorten the reaction cycle from the traditional "hours" to "minutes," thereby greatly improving equipment utilization efficiency and overall throughput. Currently, my country has accumulated rich engineering experience and industrial foundation in the application of irradiation technology, especially in the field of wastewater and waste treatment, where several electron beam irradiation demonstration projects have been built, forming a relatively complete technical system and industrialization foundation. This provides solid technical support and a feasible industrialization path for the development of irradiation-enhanced lithium battery recycling technology, which will help promote the rapid and stable large-scale application of this technology, reduce technical risks and economic costs in the promotion process, and make forward-looking technical reserves to cope with the growing wave of battery retirement in the future.

[0006] Currently, lithium-ion battery recycling mainly involves three steps: pretreatment, metal extraction, and metal separation. Pretreatment typically refers to dismantling, crushing, and pulverizing. To facilitate lithium-ion battery recycling, battery manufacturers must consider rapid, efficient, and safe dismantling processes in their battery assembly designs. In the development of the metal extraction step in the recycling process, common methods include pyrometallurgical processes, hydrometallurgical recycling methods, and direct recycling methods. While pyrometallurgy is widely used in industry due to its simplicity (no pretreatment required) and efficiency, it also has drawbacks, including the need for extremely high temperatures (1400°C or higher) and the generation of toxic gases, leading to high infrastructure investment. Direct recycling methods have advantages because they allow batteries to be used directly after regeneration, avoiding lengthy and expensive purification steps. However, this process requires rigorous sorting / pretreatment procedures, a clear assessment of the battery's state of charge and composition (considering lithium loss due to solid electrolyte interface thickening), and consistent purification, making it a less flexible technology. Hydrometallurgical processes, due to their high metal leaching rates and satisfactory purity of the recycled products, are one of the most viable options. However, techniques using hydrochloric acid (HCl), phosphoric acid (H3PO4), and other inorganic acids pose hazards to workers and the environment, primarily due to the generation of harmful byproducts such as Cl2, sulfur oxides, and nitrogen oxides. Therefore, organic acids such as succinic acid, citric acid, and malic acid are currently considered promising alternatives. However, organic acids also face a number of challenges. For example, additional reducing agents, such as hydrogen peroxide (H2O2), glucose, or other substances, are required to accelerate the process. According to the classic “4H” principle, this reduces the economic returns. Recently, eutectic solvents have been reported as effective leaching and reducing agents, but the process requires long reaction times (>24 hours), high reaction temperatures (>135°C), and auxiliary electrochemical processes to recover the solvent (A contact-electro-catalytic cathode recycling method for spent lithium-ion batteries, Nature Energy Volume 8 October 2023 1137-1144).

[0007] Based on this, this study proposes a method for selective leaching of metals from waste lithium-ion battery materials using irradiation activation. This method generates highly active species by irradiating and activating oxidants, constructing a lithium-ion battery resource recycling process with mild reaction conditions, high leaching efficiency, and environmental friendliness. It has significant engineering feasibility and industrialization potential, and can provide a scalable technical path for the green recycling and high-value utilization of retired power batteries. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art by providing a simple and environmentally friendly method for selective leaching of metals using an oxidant in an aqueous solution, specifically a method for selectively leaching metals from waste lithium battery materials based on irradiation activation. The solution used in this reaction process is non-toxic and harmless, possessing the potential for industrial-scale metal leaching and recycling.

[0009] The objective of this invention can be achieved through the following technical solutions.

[0010] This invention provides a method for selectively leaching metals from waste lithium-ion battery materials based on irradiation activation, comprising the following steps:

[0011] The lithium battery material to be leached is dispersed in an aqueous solution containing an oxidant, and the metal in the material is leached out by radiation.

[0012] Furthermore, the metals include one or more of lithium, cobalt, and nickel.

[0013] Furthermore, the oxidants include persulfate (PMS), perdisulfate (PDS), and hydrogen peroxide.

[0014] Furthermore, the concentration of the aqueous solution of the oxidant is 0.01-1 mol / L.

[0015] Furthermore, the mass ratio of the oxidant to the lithium battery material to be leached is 0.04~15:1.

[0016] Furthermore, the irradiation was carried out at room temperature (25°C).

[0017] Furthermore, the irradiation time is 5-80 min.

[0018] Furthermore, irradiation is carried out in an irradiation device, including X-ray, gamma-ray, and electron beam irradiation.

[0019] Furthermore, the irradiation dose is 0-400 kGy.

[0020] Furthermore, the metal leaching rate reaches over 95%.

[0021] Traditional hydrometallurgical leaching of metals from lithium batteries is typically cumbersome and complex, requiring the addition of large amounts of strong acid and a reaction cycle of several hours. This invention utilizes hydrated electrons generated in situ by water irradiation to activate oxidants, producing highly reactive species that rapidly disrupt the crystal lattice of lithium battery materials. This reduces metal leaching time from hours to minutes, significantly improving processing efficiency. Currently, the metal leaching rate of this system exceeds 95%, and the entire process is mild, green, environmentally friendly, low-cost, and easy to operate, showing potential for industrial-scale metal recycling. Applying this technology to the leaching of metals from lithium batteries holds the promise of shifting from "chemical kinetic limitations" to "physical efficiency-driven" approaches.

[0022] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention provides a green method for recovering metals from spent lithium batteries. The lithium battery material to be leached is dispersed in an aqueous solution containing an oxidant, and the activation of the oxidant is enhanced using irradiation technology, thereby achieving efficient metal leaching. The entire process has advantages such as being mild, green, environmentally friendly, efficient, and easy to operate. It requires no additional catalyst and does not use strong acids, toxic cyanides, or volatile organic solvents, demonstrating great potential in environmental protection and resource recycling.

[0023] 2. The irradiation technology used in this invention generates a large number of strong oxidizing free radicals in situ, which can significantly accelerate the dissolution rate of metal ions. Through rapid kinetic control, the reaction cycle is shortened from "hours" to "minutes", which greatly improves the equipment turnover rate while ensuring a high recovery rate of key strategic metals such as lithium, nickel, and cobalt.

[0024] 3. This invention leverages my country's rich experience and mature industrial base in the application of irradiation technology to ensure that the method for recycling lithium batteries using irradiation technology can be quickly and smoothly transformed from laboratory to large-scale industrial application, reducing the barriers and risks of technology promotion. Attached Figure Description

[0025] Figure 1 The figures show bar charts and selectivity graphs of lithium leaching rate from lithium cobalt oxide material leached by sodium persulfate aqueous solution under different irradiation doses in Example 1.

[0026] Figure 2 The figures show bar charts and selectivity graphs of lithium leaching rate from ternary lithium (NCM523) material leached with sodium persulfate aqueous solution under different irradiation doses in Example 2.

[0027] Figure 3 This is a leaching rate diagram of lithium cobalt oxide metal leached from aqueous solutions of different oxidants in Example 3.

[0028] Figure 4This is a leaching rate diagram of ternary lithium (NCM523) metal leached from aqueous solutions of different oxidants in Example 3.

[0029] Figure 5 This is a leaching rate diagram of lithium cobalt oxide metal leached from aqueous solutions with different oxidant concentrations in Example 4.

[0030] Figure 6 The leaching rate diagram shows the leaching rate of lithium cobalt oxide metal under non-irradiation and irradiation (400 kgy) conditions in Example 5.

[0031] Figure 7 This is a schematic diagram illustrating the process of a green method for recovering metals from waste lithium batteries provided by the present invention. Detailed Implementation

[0032] The following examples further illustrate specific implementations of the present invention, but the implementation and protection of the present invention are not limited thereto. It should be noted that any processes not specifically described below are those that can be implemented or understood by those skilled in the art by referring to existing technology. Reagents or instruments whose manufacturers are not specified are considered to be conventional products that can be purchased commercially.

[0033] Example 1 50 mg of lithium cobalt oxide material was dispersed in 10 mL of sodium persulfate aqueous solution (0.5 mol / L) (1.1905 g), and irradiated with gamma at 5 °C for 20 min at a dose of 100 kGy. The lithium leaching rate was 99.2%.

[0034] from Figure 1 The data clearly show that as the irradiation dose increases, the proportion of lithium in the liquid continuously increases. When the irradiation dose is 70 kGy, the lithium leaching rate can reach more than 90%, and when the irradiation dose is 100 kGy, the lithium leaching rate can reach 99.2%.

[0035] Example 2 50 mg of ternary lithium (NCM523) battery material was dispersed in 10 mL of sodium persulfate aqueous solution (0.3 mol / L), and irradiated with gamma at 25 °C for 20 min at a dose of 100 kGy. The lithium leaching rate was 98.4%.

[0036] from Figure 2 The data clearly show that as the irradiation dose increases, the proportion of lithium in the liquid continuously increases. When the irradiation dose is 70 kGy, the lithium leaching rate can reach more than 95%, and when the irradiation dose is 100 kGy, the lithium leaching rate can reach 98.4%.

[0037] Example 3 50 mg of lithium cobalt oxide and 50 mg of ternary lithium (NCM523) material were dispersed in 10 mL of aqueous solutions of PMS (sodium persulfate), PDS (sodium persulfate), and H2O2, respectively. The concentrations of PMS, PDS, and H2O2 were all 0.1 mol / L. The materials were then irradiated with gamma at 25 °C for 5 min at a dose of 30 kGy.

[0038] Figure 3 The leaching rates of lithium cobalt oxide metal by leaching with aqueous solutions of different oxidants are shown. Figure 4 The leaching rates of ternary lithium (NCM523) metal leached from aqueous solutions of different oxidants are shown.

[0039] from Figure 3 , Figure 4 The data clearly show that PDS aqueous solution exhibits higher selectivity for lithium metal and a higher lithium leaching rate compared to other oxidant aqueous solutions. The promoting effect of lithium cobalt oxide in the PDS solution system is more pronounced, with a lithium leaching rate twice that of other oxidant aqueous solutions. PMS aqueous solution shows higher leaching rates for cobalt and nickel.

[0040] As can be seen from Examples 1-3, PDS aqueous solution can effectively leach metals from different lithium battery materials, and has a certain selectivity for metallic lithium.

[0041] Example 4 50 mg of lithium cobalt oxide material was dispersed in 10 mL of H2O2 aqueous solutions of different concentrations (0.01, 0.1, 0.2, 0.6, 1 mol / L), and then irradiated with gamma at 25 °C for 20 min at a dose of 100 kGy.

[0042] from Figure 5 As can be seen, with the increase of oxidant concentration, the leaching rate of lithium gradually increases to over 95%, while the leaching rate of cobalt approaches 15%.

[0043] Example 5 50 mg of lithium cobalt oxide material was dispersed in 10 mL PDS (0.5 mol / L) and irradiated with gamma at 25 °C for 80 min, with a dose of 400 kGy.

[0044] from Figure 6 It can be seen that when the irradiation dose increases to 400 kGy, lithium is almost completely leached out, and the leaching rate of cobalt also increases to nearly 40%.

[0045] Figure 7 A schematic diagram of the leaching of lithium battery materials is shown.

[0046] The present invention has conducted irradiation experiments on laboratory samples in a commercial irradiation device (a fixed source chamber wet storage cobalt-60γ irradiation device, model Q(H), using a single-plate source arrangement, with a designed source capacity of 2 million curies), demonstrating that the method provided by the present invention based on irradiation activation selective leaching of metals from waste lithium battery materials has engineering potential.

[0047] The present invention provides a method for selectively leaching metals from waste lithium battery materials based on irradiation activation. The reaction process does not use strong acids, strong bases, or volatile organic solvents, and the reaction cycle is short, down to the minute level. This indicates that the reaction conditions of the method for selectively leaching metals from waste lithium battery materials based on irradiation activation provided by the present invention are mild and environmentally friendly.

[0048] The present invention provides a method for selective leaching of metals from waste lithium battery materials based on irradiation activation. The leaching rate of lithium reaches over 95% and the leaching rate of cobalt can approach 40% for waste lithium battery materials, indicating that the method for selective leaching of metals from waste lithium battery materials based on irradiation activation provided by the present invention has high leaching efficiency.

[0049] The above description represents preferred embodiments of the present invention and is not intended to limit the invention. Those skilled in the art will recognize that the present invention can be modified and varied in various ways. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for selectively leaching metals from waste lithium battery materials based on irradiation activation, characterized in that, Includes the following steps: The lithium battery material to be leached is dispersed in an aqueous solution containing an oxidant, and the metal in the material is leached out by radiation.

2. The method for selective leaching of waste lithium battery material metals based on irradiation activation according to claim 1, characterized in that, The metals mentioned include one or more of lithium, cobalt, nickel, and manganese.

3. The method for selective leaching of waste lithium battery material metals based on irradiation activation according to claim 1, characterized in that, The oxidants include peroxymonosulfate (PMS), peroxydisulfate (PDS), and hydrogen peroxide.

4. The method for selective leaching of waste lithium battery material metals based on irradiation activation according to claim 1, characterized in that, The concentration of the aqueous solution containing the oxidant is 0.01-1 mol / L.

5. The method for selective leaching of waste lithium battery material metals based on irradiation activation according to claim 1, characterized in that, The mass ratio of the oxidant to the lithium battery material to be leached is 0.04~15:

1.

6. The method for selective leaching of waste lithium battery material metals based on irradiation activation according to claim 1, characterized in that, The irradiation was carried out at room temperature.

7. The method for selective leaching of waste lithium battery material metals based on irradiation activation according to claim 1, characterized in that, The irradiation time is 5-80 min.

8. The method for selective leaching of waste lithium battery material metals based on irradiation activation according to claim 1, characterized in that, The irradiation includes X-rays, gamma rays, and electron beam irradiation.

9. The method for selective leaching of waste lithium battery material metals based on irradiation activation according to claim 1, characterized in that, The irradiation is carried out in an irradiation device, and the irradiation dose is 0-400 kGy.

10. The method for selective leaching of waste lithium battery material metals based on irradiation activation according to claim 1, characterized in that, The metal leaching rate is over 95%.

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