Washing-out agent and washing-out method for washing out hexafluorophosphate radicals in waste batteries

Abstract

The invention belongs to the technical field of battery recovery, and more specifically relates to an eluant and an elution method for eluting hexafluorophosphate radicals in waste batteries. The invention provides an eluting agent for eluting hexafluorophosphate radicals in waste batteries. The eluting agent comprises an anionic surfactant, inorganic salt and water. According to the method, the battery cell of the waste battery is soaked in the eluent, the eluent containing the hexafluorophosphate radicals can be obtained after washing-out treatment and filtration, direct washing-out of the hexafluorophosphate radicals in the waste battery is achieved, the washing-out rate is larger than or equal to 90%, and the washing-out rate is larger than or equal to 90%. The method has the advantages of being simple in washing process, high in safety, low in equipment requirement, small in energy consumption, low in cost, environmentally friendly and the like, is suitable for large-scale washing treatment, and has high economical efficiency and practicability.

Description

Technical Field

[0001] The present application belongs to the technical field of battery recycling, and more specifically, relates to an eluting agent and an eluting method for eluting hexafluorophosphate from waste batteries. Background Art

[0002] In recent years, with the increase in battery production capacity, there are more and more waste batteries. The recycling and utilization of waste battery materials has considerable economic value and environmental benefits. At present, the research on the recycling of waste batteries mainly focuses on the recycling of positive and negative electrode materials, and there are fewer studies on the recycling and utilization of electrolytes. The main components of electrolytes include organic solvents, electrolytes, and additives. At present, the electrolyte salts in commercial electrolytes are generally lithium hexafluorophosphate (LiPF6), sodium hexafluorophosphate (NaPF6), sodium hexafluorophosphate (NH4PF6), etc., and the commonly used organic solvents are ethylene carbonate (EC), dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC) and propylene carbonate (PC). Additives are non-essential components in electrolytes and are added in small amounts. They are mainly used to improve the conductivity, rate performance and flame retardancy of electrolytes, and to improve the safety and cycle life of batteries.

[0003] Patent document CN108666644A discloses a method for recovering fluorine and lithium from waste electrolyte of lithium batteries, wherein CaO or Ca(OH)2 is reacted with waste electrolyte of lithium batteries to obtain fluorine and lithium. 2+ It reacts with fluoride ions in the electrolyte to generate CaF2, and then uses multi-stage manganese fiber adsorption columns and titanium fiber adsorption columns to physically and directional adsorb lithium ions, thereby recovering fluorine and lithium in the electrolyte. Patent document CN108155434A discloses a method for recovering lithium from waste electrolyte of lithium-ion batteries, by mixing the waste electrolyte with a halide solution containing a large cation radius to react, and PF6 in the electrolyte is recovered. -1 The whole is separated, and then the lithium-containing solution obtained after separation is deeply purified and lithium precipitation is carried out to obtain lithium carbonate. Patent document CN116231137A discloses a method for recycling and resource utilization of waste lithium-ion battery electrolyte, which is to leach the waste lithium battery after cutting in an organic solvent, and then treat the filtrate with a lithium-containing acid remover, distill, complex, cool and crystallize, and heat and dissociate to obtain lithium hexafluorophosphate solid. The above methods cannot fully wash out the hexafluorophosphate in the waste lithium-ion battery.

[0004] Patent document CN118630352A discloses a process for recycling the electrolyte of retired lithium batteries, which involves immersing the disassembled retired lithium batteries in a lithium hydroxide solution, adding a catalyst, activating the reactants through coordination, electron transfer, etc., thereby promoting the chemical reaction between the lithium battery waste and the lithium hydroxide solution, and calcining the collected filter residue at 600-800°C in an inert gas environment, then placing it in an organic solvent and passing PF5 gas, and freezing and crystallizing it to obtain lithium hexafluorophosphate. However, the above process is complex, energy-intensive, and requires high equipment, and is not suitable for large-scale recycling.

[0005] Therefore, developing a low-cost, low-energy method for fully washing out hexafluorophosphate from waste batteries has a wide range of applications. Summary of the invention

[0006] In view of the defects of the prior art, the purpose of the present application is to provide a washing agent and a washing method for washing out hexafluorophosphate in waste batteries, aiming to solve the problems of complex process, high energy consumption, high equipment requirements, great washing difficulty and low washing rate of hexafluorophosphate in washing out hexafluorophosphate in waste batteries limited by the prior art.

[0007] To achieve the above objectives, in a first aspect, the present application provides an eluting agent for eluting hexafluorophosphate from waste batteries, wherein the eluting agent comprises the following components in parts by mass: 0.3-1.2 parts of surfactant, 11-18 parts of inorganic salt, 100 parts of water; the surfactant includes an anionic surfactant.

[0008] Preferably, the anionic surfactant is selected from one or more of sodium dodecyl sulfate, sodium hexadecyl sulfate, and sodium lauryl alcohol polyoxyethylene ether sulfate.

[0009] Preferably, the inorganic salt is selected from one or more of sodium chloride, sodium sulfate, ammonium sulfate and lithium sulfate.

[0010] Preferably, the above-mentioned surfactant also includes a nonionic surfactant.

[0011] Further preferably, the above nonionic surfactant is selected from one or more of NP10 and OP-10.

[0012] Preferably, the mass ratio of the anionic surfactant to the nonionic surfactant is greater than or equal to 7:3.

[0013] In a second aspect, the present application provides a method for washing out hexafluorophosphate from waste batteries, comprising the following steps: S1, soaking the battery cell of the waste battery in the above-mentioned eluting agent, performing eluting treatment, and obtaining a suspension; the electrolyte of the above-mentioned waste battery includes at least one of lithium hexafluorophosphate, sodium hexafluorophosphate, and lithium ammonium hexafluorophosphate; S2. Filter the suspension to obtain an eluate containing hexafluorophosphate.

[0014] Preferably, in the above-mentioned elution treatment, a pH buffer is used to adjust the pH of the elution environment to 7.0-7.5.

[0015] Preferably, the pH buffer is selected from one or more of ammonium acetate, ammonium carbonate and ammonium bicarbonate.

[0016] Preferably, the soaking time is 10 min to 60 min.

[0017] Preferably, the waste batteries are disassembled under a protective atmosphere to obtain battery cells of the waste batteries.

[0018] Preferably, the protective atmosphere gas is selected from one or more of nitrogen, argon and helium.

[0019] In general, the above technical solutions conceived by this application have the following technical advantages compared with the prior art: (1) The eluting agent provided in the present application for washing out hexafluorophosphate in waste batteries comprises a surfactant, an inorganic salt and water, wherein the surfactant is an anionic surfactant. The eluting agent provided in the present application can effectively wash out hexafluorophosphate in waste batteries, and the washing rate is ≥90%.

[0020] (2) The eluting agent for eluting hexafluorophosphate from waste batteries provided in the present application can destroy the bonding effect between the current collector and the electrode material through the synergistic effect of the anionic surfactant and the non-ionic surfactant components, so that the hexafluorophosphate adsorbed on the surface of the electrode material can be fully eluted, thereby further improving the elution rate of hexafluorophosphate from waste batteries, and even achieving complete elution of hexafluorophosphate from waste batteries.

[0021] (3) The method for washing out hexafluorophosphate from waste batteries using the above-mentioned washing agent provided in the present application is to soak the battery core of the waste battery in the above-mentioned washing agent, wash it out, and then filter it to obtain an washing liquid containing hexafluorophosphate, thereby directly washing out the hexafluorophosphate from the waste battery. Compared with the prior art, the method for washing out hexafluorophosphate from waste batteries provided in the present application does not require distillation, heating, etc. of the electrolyte, and the whole process avoids the use of high energy consumption and corrosive chemical reagents. It has the advantages of simple washing process, high safety, low equipment requirements, low energy consumption, low cost, and environmental friendliness. It is suitable for large-scale washing out and has high economy and practicality. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present application more clear, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described here are only used to explain the present application and are not used to limit the present application.

[0023] In the description of this application, it should be understood that the term "and / or" is a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. The symbol " / " herein indicates that the associated objects are in an or relationship, for example, A / B means A or B.

[0024] In the description of the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0025] In the description of the embodiments of the present application, unless otherwise specified, “plurality” means two or more than two.

[0026] Existing methods for washing out hexafluorophosphate (PF6 - ) cannot effectively wash out the hexafluorophosphate adsorbed on the surface of the electrode material, and the washing process is complex, the energy consumption is high, and the hexafluorophosphate washing rate is low. Based on this, the present application provides an washing agent for washing out the hexafluorophosphate in waste batteries, which includes the following components by mass: 0.3-1.2 parts of a surfactant, 11-18 parts of an inorganic salt, and 100 parts of water; The above-mentioned surfactants include anionic surfactants.

[0027] The inventor of the present application unexpectedly discovered through experiments that the use of the above-mentioned elution agent to soak the waste batteries can effectively improve the elution rate of hexafluorophosphate. The elution agent provided by the present application can accelerate the elution rate of hexafluorophosphate in the electrolyte by adding anionic surfactants. Furthermore, by adjusting the amount of anionic surfactants in the elution agent, the hexafluorophosphate in the electrolyte of the waste batteries can be effectively eluted and the elution rate can be improved.

[0028] In some embodiments, the electrolyte of the above-mentioned waste battery electrolyte includes at least one of lithium hexafluorophosphate, sodium hexafluorophosphate, and ammonium hexafluorophosphate.

[0029] In some embodiments, the above-mentioned waste batteries are one or more of waste lithium-ion batteries and waste sodium-ion batteries.

[0030] In some embodiments, the anionic surfactant is selected from one or more of sodium dodecyl sulfate (SDS), sodium hexadecyl sulfate, sodium lauryl alcohol polyoxyethylene ether sulfate, sodium dodecylbenzene sulfonate (LAS), and sodium octyl sulfonate (SABS).

[0031] In some embodiments, the inorganic salt is one or more of sodium chloride, sodium sulfate, ammonium sulfate, and lithium sulfate, which can be used to discharge waste batteries.

[0032] In some embodiments, the surfactant further includes a nonionic surfactant.

[0033] In some embodiments, the mass ratio of the anionic surfactant to the nonionic surfactant is greater than or equal to 7:3.

[0034] In some embodiments, the nonionic surfactant is selected from one or more of NP10 and OP-10.

[0035] On the other hand, the present application also provides a method for washing out hexafluorophosphate from waste batteries, comprising the following steps: S1, soaking the battery core of the waste battery in the above-mentioned eluting agent, performing eluting treatment, and obtaining a suspension; the electrolyte of the above-mentioned waste battery electrolyte includes at least one of lithium hexafluorophosphate, lithium hexafluorophosphate, sodium hexafluorophosphate, and ammonium hexafluorophosphate; S2. Filter the suspension to obtain an eluate containing hexafluorophosphate.

[0036] In some embodiments, in the above-mentioned elution process, a pH buffer is used to adjust the pH of the elution environment to 7.0-7.5, which can prevent corrosion from occurring during the elution process.

[0037] In some embodiments, the pH buffer is selected from one or more of ammonium acetate, ammonium carbonate, and ammonium bicarbonate.

[0038] In some embodiments, the soaking time is 10 min to 60 min.

[0039] In some embodiments, the waste batteries are disassembled under a protective atmosphere to obtain battery cells of the waste batteries.

[0040] In some embodiments, the above-mentioned waste batteries are one or more of waste lithium-ion batteries and waste sodium-ion batteries.

[0041] In some embodiments, the battery cell includes a positive electrode material, a negative electrode material, a current collector, a separator and an electrolyte.

[0042] In some embodiments, the protective atmosphere gas is selected from one or more of nitrogen, argon, and helium.

[0043] The present application discloses a method for washing out hexafluorophosphate from waste batteries using the above-mentioned washing agent. By immersing the battery core of the waste battery in the above-mentioned washing agent, the hexafluorophosphate on the surface of the electrode material and in the electrolyte can be washed out, thereby achieving complete washing out of the hexafluorophosphate in the waste battery. The washing method provided by the present application has the advantages of simple operation, high safety, low equipment requirements, low energy consumption, low cost, and environmental friendliness. At the same time, the washing rate of hexafluorophosphate is high, which is suitable for large-scale washing out treatment and has great economic benefits.

[0044] It should be understood that materials of the same or similar type, model, quality, nature or function as the reagents and instruments used in the following examples can be used to implement the present application. The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following examples can be obtained from commercial sources unless otherwise specified.

[0045] The following are examples and comparative examples: Example 1 1) Prepare the eluent According to parts by mass, 0.56 parts of anionic surfactant sodium dodecyl sulfate (SDS), 11.17 parts of NaCl and 100 parts of water were mixed and stirred to form a uniform solution for later use.

[0046] 2) Dismantle and crush the waste lithium-ion batteries under a nitrogen atmosphere to obtain battery cells containing positive electrode materials, negative electrode materials, current collectors, separators, and electrolytes.

[0047] 3) Soak the cells of the waste lithium-ion batteries in the elution agent, let it stand for elution treatment, and add ammonium acetate to adjust the pH of the elution environment to neutral. The elution treatment temperature is room temperature, and the soaking time is 30 minutes to obtain a suspension, which is then filtered. The content of hexafluorophosphate in the filtrate is determined, and the elution rate of hexafluorophosphate in the waste lithium-ion batteries is calculated.

[0048] Among them, the washing rate of hexafluorophosphate (%) = (the content of hexafluorophosphate in the filtrate / the content of hexafluorophosphate in the waste battery) × 100%. The results are shown in Table 1.

[0049] Example 2 1) Prepare the eluent According to parts by mass, 0.33 parts of anionic surfactant sodium dodecyl sulfate (SDS), 11.15 parts of (NH4)2SO4 and 100 parts of water were mixed and stirred to form a uniform solution for later use.

[0050] 2) Dismantle and crush the waste lithium-ion batteries under a nitrogen atmosphere to obtain battery cells containing positive electrode materials, negative electrode materials, current collectors, separators, and electrolytes.

[0051] 3) The cells of the waste lithium-ion battery were immersed in an elution agent, left to stand for elution treatment, and ammonium acetate was added to adjust the pH of the elution environment to neutral. The elution treatment temperature was room temperature, and the immersion time was 30 min to obtain a suspension. After filtering, the content of hexafluorophosphate in the filtrate was determined, and the elution rate of hexafluorophosphate was calculated according to the method provided in Example 1. The results are shown in Table 1.

[0052] Example 3 1) Prepare the eluent According to the weight ratio, 1.2 parts of anionic surfactant sodium dodecyl sulfate (SDS), 18 parts of Na2SO4 and 100 parts of water were mixed and stirred to form a uniform solution for later use.

[0053] 2) Dismantle and crush the waste lithium-ion batteries under a nitrogen atmosphere to obtain battery cells containing positive electrode materials, negative electrode materials, current collectors, separators, and electrolytes.

[0054] 3) The cells of the waste lithium-ion battery were immersed in an elution agent, left to stand for elution treatment, and ammonium acetate was added to adjust the pH of the elution environment to neutral. The elution treatment temperature was room temperature, and the immersion time was 30 min to obtain a suspension. After filtering, the content of hexafluorophosphate in the filtrate was determined, and the elution rate of hexafluorophosphate was calculated according to the method provided in Example 1. The results are shown in Table 1.

[0055] Example 4 1) Prepare the eluent According to the weight ratio, 0.84 parts of anionic surfactant sodium dodecyl sulfate (SDS), 0.36 parts of nonionic surfactant NP-10, 18 parts of Na2SO4 and 100 parts of water were mixed and stirred to form a uniform solution for use.

[0056] 2) Dismantle and crush the waste lithium-ion batteries under a nitrogen atmosphere to obtain battery cells containing positive electrode materials, negative electrode materials, current collectors, separators, and electrolytes.

[0057] 3) The cells of the waste lithium-ion battery were immersed in an elution agent, left to stand for elution treatment, and ammonium acetate was added to adjust the pH of the elution environment to neutral. The elution treatment temperature was room temperature, and the immersion time was 30 min to obtain a suspension. After filtering, the content of hexafluorophosphate in the filtrate was determined, and the elution rate of hexafluorophosphate was calculated according to the method provided in Example 1. The results are shown in Table 1.

[0058] Example 5 1) Prepare the eluent According to the weight ratio, 0.96 parts of anionic surfactant sodium dodecyl sulfate (SDS), 0.24 parts of nonionic surfactant NP-10, 18 parts of Na2SO4 and 100 parts of water were mixed and stirred to form a uniform solution for use.

[0059] 2) Dismantle and crush the waste lithium-ion batteries under a nitrogen atmosphere to obtain battery cells containing positive electrode materials, negative electrode materials, current collectors, separators, and electrolytes.

[0060] 3) The cells of the waste lithium-ion battery were immersed in an elution agent, left to stand for elution treatment, and ammonium acetate was added to adjust the pH of the elution environment to neutral. The elution treatment temperature was room temperature, and the immersion time was 30 min to obtain a suspension. After filtering, the content of hexafluorophosphate in the filtrate was determined, and the elution rate of hexafluorophosphate was calculated according to the method provided in Example 1. The results are shown in Table 1.

[0061] Example 6 1) Prepare the eluent According to the weight ratio, 1.08 parts of anionic surfactant sodium dodecyl sulfate (SDS), 0.12 parts of nonionic surfactant NP-10, 18 parts of Na2SO4 and 100 parts of water were mixed and stirred to form a uniform solution for use.

[0062] 2) Dismantle and crush the waste lithium-ion batteries under a nitrogen atmosphere to obtain battery cells containing positive electrode materials, negative electrode materials, current collectors, separators, and electrolytes.

[0063] 3) The cells of the waste lithium-ion battery were immersed in an elution agent, left to stand for elution treatment, and ammonium acetate was added to adjust the pH of the elution environment to neutral. The elution treatment temperature was room temperature, and the immersion time was 30 min to obtain a suspension. After filtering, the content of hexafluorophosphate in the filtrate was determined, and the elution rate of hexafluorophosphate was calculated according to the method provided in Example 1. The results are shown in Table 1.

[0064] Comparative Example 1 1) Prepare the eluent The anionic surfactant in Example 1 is replaced by the cationic surfactant hexadecyltrimethylammonium chloride (1631), and the rest is the same as Example 1, and then stirred to form a uniform solution for use.

[0065] 2) Dismantle and crush the waste lithium-ion batteries under a nitrogen atmosphere to obtain battery cells containing positive electrode materials, negative electrode materials, current collectors, separators, and electrolytes.

[0066] 3) The cells of the waste lithium-ion battery were immersed in an elution agent, left to stand for elution treatment, and ammonium acetate was added to adjust the pH of the elution environment to neutral. The elution treatment temperature was room temperature, and the immersion time was 30 min to obtain a suspension. After filtering, the content of hexafluorophosphate in the filtrate was determined, and the elution rate of hexafluorophosphate was calculated according to the method provided in Example 1. The results are shown in Table 1.

[0067] Comparative Example 2 1) Prepare the eluent The anionic surfactant in Example 1 was replaced by the nonionic surfactant NP10, and the other steps were the same as in Example 1. The mixture was stirred to form a uniform solution for later use.

[0068] 2) Dismantle and crush the waste lithium-ion batteries under a nitrogen atmosphere to obtain battery cells containing positive electrode materials, negative electrode materials, current collectors, separators, and electrolytes.

[0069] 3) The cells of the waste lithium-ion battery were immersed in an elution agent, left to stand for elution treatment, and ammonium acetate was added to adjust the pH of the elution environment to neutral. The elution treatment temperature was room temperature, and the immersion time was 30 min to obtain a suspension. After filtering, the content of hexafluorophosphate in the filtrate was determined, and the elution rate of hexafluorophosphate was calculated according to the method provided in Example 1. The results are shown in Table 1.

[0070] Comparative Example 3 1) Prepare the eluent According to parts by mass, 0.2 parts of anionic surfactant sodium dodecyl sulfate (SDS), 11.15 parts of Na2SO4 and 100 parts of water were mixed and stirred to form a uniform solution for later use.

[0071] 2) Dismantle and crush the waste lithium-ion batteries under a nitrogen atmosphere to obtain battery cells containing positive electrode materials, negative electrode materials, current collectors, separators, and electrolytes.

[0072] 3) The cells of the waste lithium-ion battery were immersed in an elution agent, left to stand for elution treatment, and ammonium acetate was added to adjust the pH of the elution environment to neutral. The elution treatment temperature was room temperature, and the immersion time was 30 min to obtain a suspension. After filtering, the content of hexafluorophosphate in the filtrate was determined, and the elution rate of hexafluorophosphate was calculated according to the method provided in Example 1. The results are shown in Table 1.

[0073] Comparative Example 4 1) Prepare the eluent According to parts by mass, 1.4 parts of anionic surfactant sodium dodecyl sulfate (SDS), 11.15 parts of Na2SO4 and 100 parts of water were mixed and stirred to form a uniform solution for later use.

[0074] 2) Dismantle and crush the waste lithium-ion batteries under a nitrogen atmosphere to obtain battery cells containing positive electrode materials, negative electrode materials, current collectors, separators, and electrolytes.

[0075] 3) The cells of the waste lithium-ion battery were immersed in an elution agent, left to stand for elution treatment, and ammonium acetate was added to adjust the pH of the elution environment to neutral. The elution treatment temperature was room temperature, and the immersion time was 30 min to obtain a suspension. After filtering, the content of hexafluorophosphate in the filtrate was determined, and the elution rate of hexafluorophosphate was calculated according to the method provided in Example 1. The results are shown in Table 1.

[0076] Comparative Example 5 1) Prepare the eluent According to the weight ratio, 0.6 parts of anionic surfactant sodium dodecyl sulfate (SDS), 0.6 parts of nonionic surfactant NP-10, 18 parts of Na2SO4 and 100 parts of water were mixed and stirred to form a uniform solution for use.

[0077] 2) Dismantle and crush the waste lithium-ion batteries under a nitrogen atmosphere to obtain battery cells containing positive electrode materials, negative electrode materials, current collectors, separators, and electrolytes.

[0078] 3) The cells of the waste lithium-ion battery were immersed in an elution agent, left to stand for elution treatment, and ammonium acetate was added to adjust the pH of the elution environment to neutral. The elution treatment temperature was room temperature, and the immersion time was 30 min to obtain a suspension. After filtering, the content of hexafluorophosphate in the filtrate was determined, and the elution rate of hexafluorophosphate was calculated according to the method provided in Example 1. The results are shown in Table 1.

[0079] Experiments found that the electrode material structure partially collapsed.

[0080] Table 1 Washout rate of hexafluorophosphate in Examples 1 to 6 and Comparative Examples 1 to 5

[0081] As can be seen from Table 1, when the washing agent provided by the present application is used to wash out the waste lithium-ion batteries, the washing rate of hexafluorophosphate in the waste lithium-ion batteries is ≥90%, and the hexafluorophosphate can be effectively washed out. Compared with the existing washing method of hexafluorophosphate in waste lithium-ion batteries, the washing method provided by the present application can fully wash out the hexafluorophosphate in the waste batteries under the conditions of low cost and low energy consumption, and has high environmental value and economic benefits. At the same time, the structure of the electrode material after washing out remains intact, which is conducive to the subsequent recovery of the electrode material, thereby bringing greater economic benefits.

[0082] The elution rate of hexafluorophosphate in Example 4 is slightly higher than that in Example 1. The possible reason is that the elution agent formula provided in Example 4 contains a non-ionic surfactant, which can destroy the bonding effect between the current collector and the electrode material. At the same time, under the synergistic effect of the anionic surfactant, the hexafluorophosphate adsorbed on the surface of the electrode material is fully eluted, and even the hexafluorophosphate is completely eluted.

[0083] The washing-out rates of hexafluorophosphate in Comparative Examples 1 and 2 were only 13% and 36%, respectively, indicating that only adding cationic surfactants or nonionic surfactants could not effectively wash out hexafluorophosphate in waste lithium-ion batteries.

[0084] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. An eluting agent for eluting hexafluorophosphate from waste batteries, characterized in that: The eluent comprises the following components in parts by mass: 0.3-1.2 parts of a surfactant, 11-18 parts of an inorganic salt, and 100 parts of water; the surfactant includes an anionic surfactant.

2. The eluent according to claim 1, characterized in that The anionic surfactant is selected from one or more of sodium lauryl sulfate, sodium hexadecyl sulfate, and sodium lauryl alcohol polyoxyethylene ether sulfate.

3. The eluent according to claim 1, characterized in that The inorganic salt is selected from one or more of sodium chloride, sodium sulfate, ammonium sulfate and lithium sulfate.

4. The eluting agent according to any one of claims 1 to 3, characterized in that The surfactant also includes nonionic surfactants.

5. The eluting agent according to claim 4, characterized in that The mass ratio of the anionic surfactant to the nonionic surfactant is greater than or equal to 7:

3.

6. The eluting agent according to claim 4 or 5, characterized in that The nonionic surfactant is selected from one or more of NP10 and OP-10.

7. A method for washing out hexafluorophosphate from waste batteries, characterized in that: The steps include: S1. Soaking the battery cell of the waste battery in the eluting agent according to any one of claims 1 to 6, performing elution treatment, and obtaining a suspension; the electrolyte of the waste battery comprises at least one of lithium hexafluorophosphate, sodium hexafluorophosphate, and lithium ammonium hexafluorophosphate; S2. Filter the suspension to obtain an eluate containing hexafluorophosphate.

8. The washing method according to claim 7, characterized in that: In the elution process, a pH buffer is used to adjust the pH of the elution environment to 7.0-7.5; The pH buffer is selected from one or more of ammonium acetate, ammonium carbonate and ammonium bicarbonate.

9. The elution method according to claim 7, characterized in that: The soaking time is 10 to 60 minutes.

10. The elution method according to claim 7, characterized in that: Disassembling the waste battery under a protective atmosphere to obtain the battery core of the waste battery; The gas of the protective atmosphere is selected from one or more of nitrogen, argon and helium.

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