Method for recycling metal of waste lithium battery by utilizing biomineralization of engineered escherichia coli and application

Abstract

The invention provides a method for recycling metal of a waste lithium battery by utilizing biomineralization of engineered escherichia coli and application. The invention provides a metal tolerance biomineralization method. The metal tolerance biomineralization method comprises the following steps: designing double-plasmid escherichia coli containing efficient urease expression genes; optimizing conditions for inducing expression of urease; and biologically mineralizing the engineering bacteria in the metal leachate of the waste lithium ion battery. The core of the method is that the recombined urease is utilized to catalyze urea hydrolysis to generate carbonate ions, and the carbonate ions are combined with metal ions such as lithium, manganese, cobalt and nickel in the leachate so as to carry out biological mineralization, so that efficient recovery of the metal ions is realized. The method has the advantages of simplicity in operation, low cost, environmental friendliness and the like, the recovery rates of lithium, manganese, cobalt and nickel can reach about 90%, and a new technical approach is provided for resource utilization of waste lithium batteries.

Description

Technical Field

[0001] The present invention relates to the cross - technical field of synthetic biology and biomineralization, and relates to a method and application for recycling metal from waste lithium batteries by using engineered Escherichia coli biomineralization, which is particularly suitable for efficiently recycling metal ions such as lithium, manganese, cobalt, nickel, etc. from waste batteries such as lithium - ion batteries and nickel - metal hydride batteries. Background Art

[0002] Lithium - ion batteries are rechargeable batteries with lithium and its compounds as the core materials. With the wide application of lithium - ion batteries, the treatment and metal recycling of a large number of waste lithium batteries generated have become important topics in the fields of environment and resources. Traditional metal recycling methods, such as pyrometallurgy and hydrometallurgy, have disadvantages such as serious environmental pollution, high energy consumption, and low resource utilization rate. In recent years, as a green and sustainable metal recycling method, the biological method has received increasing attention.

[0003] Biomineralization refers to the process in which dissolved metal ions are deposited to form solid minerals in vivo or in the external environment of an organism through the action of an organism or microorganism. Biomineralization technology uses microorganisms and their metabolites to catalyze mineral formation, which has the advantages of environmental friendliness and simple operation, and shows great application potential in the field of metal recycling.

[0004] Although there have been reports on using recombinant Escherichia coli expressing urease for biomineralization technology, there are still the following problems in its specific application in the metal recycling of waste lithium batteries: 1. The metal recycling efficiency is relatively low, especially the recovery rates of key metals such as lithium, cobalt, and nickel do not meet the industrial requirements. 2. Technical details (such as parameters like metal ion concentration, pH value, temperature, etc.) are not optimized for the leachate of waste lithium batteries. 3. There is a lack of detailed description of the purity and reuse value of the mineralized product. Summary of the Invention

[0005] In view of the above problems, the purpose of the present invention is to provide a method and application for recycling metal from waste lithium batteries by using engineered Escherichia coli biomineralization, aiming to efficiently and greenly recycle metal elements such as lithium, manganese, cobalt, nickel, etc. from waste lithium batteries through biomineralization technology. The present invention significantly improves the metal recovery rate and the purity of the mineralized product by optimizing gene construction, expression conditions, and mineralization reaction parameters, and at the same time demonstrates its application potential in industrial fields such as the preparation of lithium - battery cathode materials.

[0006] To achieve the above - mentioned purpose, according to one aspect of the present invention, there is provided an engineered Escherichia coli for biomineralization, which is characterized by comprising Escherichia coli into which a double - plasmid containing a high - efficiency urease expression gene has been transferred.

[0007] According to another aspect of the present invention, the present invention provides an efficient induction expression method based on the above-mentioned engineered Escherichia coli, which is characterized by including the following steps:

[0008] Inoculate the recombinant urease strain into DYT liquid medium containing 100 μg / mL Amp and 100 μg / mL Kan, and culture it in a shaker at 220 rpm and 37 °C for 2.5 hours until the OD 600 reaches 0.6 - 0.8.

[0009] Add IPTG with a final concentration of 0.5 mM and NiCl 2 for induction, and culture it in a shaker at 20 °C and 220 rpm for 16 hours until the OD 600 reaches 2.0 - 2.2.

[0010] Collect the bacterial liquid to obtain engineered Escherichia coli with high expression of urease.

[0011] According to yet another aspect of the present invention, the present invention provides the application of the above-mentioned engineered Escherichia coli for biomineralization in the recovery of metal leaching solution from waste lithium-ion batteries, which is characterized in that the lithium ion concentration in the waste lithium-ion battery metal leaching solution is 0.1 - 1.0 mM, the manganese ion concentration is 0.2 - 2.0 mM, the cobalt ion concentration is 0.05 - 0.5 mM, and the nickel ion concentration is 0.1 - 1.0 mM.

[0012] As a further preference of the present invention, when the above metal concentration ranges are lithium ion concentration of 0.5 mM, manganese ion concentration of 1.0 mM, cobalt ion concentration of 0.2 mM, and nickel ion concentration of 0.5 mM, the recovery rate reaches the optimum.

[0013] According to still another aspect of the present invention, the present invention provides the application of the engineered Escherichia coli bacterial liquid obtained based on the above induction expression method in the recovery of metal leaching solution from waste lithium-ion batteries, which is characterized by including the following steps:

[0014] Mix the induced engineered Escherichia coli bacterial liquid with the metal leaching solution of waste lithium-ion batteries, and add urea with a final concentration of 10 g / L; co-incubate at 37 °C and 220 rpm in a shaker at a pH value range of 7.0 - 9.5 for 24 hours to promote the urease-catalyzed hydrolysis of urea to generate carbonate ions.

[0015] Lithium carbonate (Li 2 CO 3 ), manganese carbonate (MnCO 3 ), cobalt carbonate (CoCO 3 ), and nickel carbonate (NiCO 3Mineralization products such as () are gradually formed and deposited on the surface of the bacterial cells through the action of extracellular polymeric substances (EPS).

[0016] Filter the mineralization reaction solution and collect the Escherichia coli precipitate attached with the mineralization products; wash the precipitate three times with distilled water to remove impurities.

[0017] Place the washed precipitate in an environment of 60 °C and dry for 24 hours.

[0018] Burn the dried precipitate at 200 °C for 1 - 2 hours to remove the organic components of the bacterial cells and obtain high-purity lithium carbonate (Li 2 CO 3 ), manganese carbonate (MnCO 3 ), cobalt carbonate (CoCO 3 ), and nickel carbonate (NiCO 3 ) minerals.

[0019] As a further preference of the present invention, the above mineralization reaction has the highest mineralization efficiency at pH 8.5 - 9.0.

[0020] Through the above technical solutions conceived by the present invention, compared with the prior art, since relatively safe engineered Escherichia coli is used, it has advantages such as simple operation, low cost, and environmental friendliness in the application of lithium-ion battery recycling. Specifically, the present invention can achieve the following beneficial effects:

[0021] Strong environmental protection and green recycling: The present invention uses recombinant Escherichia coli expressing urease to catalyze the urea decomposition reaction, generate ammonia and promote the mineralization deposition of metal ions, thus avoiding the toxic waste gases and waste water generated in traditional recycling methods (such as pyrometallurgy or acid leaching). This method is non-toxic and pollution-free, and can significantly reduce the negative impact on the environment during the recycling process of waste batteries, meeting the requirements of green and environmentally friendly sustainable development.

[0022] High purity and recovery rate: Through atomic absorption spectrometry (AAS) and inductively coupled plasma optical emission spectrometry (ICP-OES) analysis, the purities of lithium, manganese, cobalt, and nickel in the mineralized products reach 98.2%, 95.3%, 93.8%, and 96.5% respectively; after repeated mineralization recycling, the recovery rates can all reach about 90%; reduce the metal waste in waste batteries and improve the utilization efficiency of resources, meeting the requirements of large-scale industrial applications.

[0023] Low cost, energy-saving and efficient: The urease-catalyzed reaction used in the present invention can be carried out at normal temperature and pressure, without high-temperature treatment or the use of toxic chemical reagents. Compared with traditional recycling methods (such as acid leaching or metallurgy), it can significantly reduce energy consumption and operating costs; the process of this method is simple, with less equipment investment, and is suitable for popularization and application by small and medium-sized enterprises.

[0024] Simple operation and stable process: The recycling process of the present invention is easy to operate and can be automated, reducing the complexity of manual intervention. Through automated fermentation equipment and large-scale reactors, continuous metal recycling can be achieved, significantly improving production efficiency and being suitable for industrial promotion and application.

[0025] Wide application of mineralized products: The recovered lithium carbonate and cobalt carbonate are used to prepare the cathode materials of lithium-ion batteries (such as LiCoO 2 ), and their electrochemical performance is comparable to that of commercial raw materials. The recovered nickel carbonate is used to prepare catalysts, which show comparable activity to commercial catalysts in different catalytic reactions and have good stability. The high purity and excellent performance of the mineralized products make them have broad application potential in the fields of energy storage, catalysis, etc. Brief Description of the Drawings

[0026] Figure 1 This is the drawing for the abstract of the specification, which is a schematic diagram of the biomineralization process of the engineered Escherichia coli in the embodiments of the present invention. The figure shows the metal mineralization products formed on the surface of the genetically modified Escherichia coli, and the mineralization products are carbonate sediments formed by key metals (such as Li, Co, Ni, Mn) in waste lithium-ion batteries under the action of microbial metabolism.

[0027] Figure 2 This is the SDS-PAGE diagram for verifying the expression of recombinant Escherichia coli urease. The molecular weights (kDa) of each subunit are as follows: UreA is 11.1, UreB is 14.0, UreC is 61.4, UreD is 29.3, UreE is 17.4, UreF is 23.0, and UreG is 23.1.

[0028] Figure 3 This is the quantitative detection of the activity of recombinant Escherichia coli urease. a: Schematic diagram of the reaction principle for the quantitative detection of urease activity; b: Determination of the quantitative standard curve of urease activity; c: Histogram of the absorbance value ΔA for the quantitative detection of urease activity (after conversion calculation, the urease activity can be obtained as 0.153 U / g DCW (U: the amount of enzyme that catalyzes the formation of 1.0 micromole of ammonia per minute at a pH value of 7.0), showing obvious urease activity compared with the control group).

[0029] Figure 4 This is the optical microscope observation diagram of the biomineralization results. a: BL21(DE3) control group; b: Light microscope image of Li mineralization in the double-plasmid experimental group; c: Light microscope image of Mn mineralization in the double-plasmid experimental group; d: Light microscope image of Ni mineralization in the double-plasmid experimental group; e: Light microscope image of Co mineralization in the double-plasmid experimental group.

[0030] Figure 5Results of AFM observation of biomineralization. a: Li double-plasmid experimental group; b: Mn double-plasmid experimental group; c: Ni double-plasmid experimental group; d: Co double-plasmid experimental group; e: BL21 control group.

[0031] Figure 6 Electron microscopy images of Li, Mn, Co, and Ni biomineralization to form corresponding carbonates (Note: The negative control group used wild-type BL21 bacteria co-cultured with metal ions without adding urease for biomineralization; the positive control group added urease to wild-type BL21 bacteria to simulate in vitro biomineralization; the experimental group used BL21 bacteria expressing recombinant urease with double plasmids for biomineralization). a: Electron microscopy image of Li negative control group; b: Electron microscopy image of Mn negative control group; c: Electron microscopy image of Ni negative control group; d: Electron microscopy image of Co negative control group; e: Electron microscopy image of Li experimental group; f: Electron microscopy image of Mn experimental group; g: Electron microscopy image of Ni experimental group; h: Electron microscopy image of Co experimental group; i: Electron microscopy image of Li positive control group; j: Electron microscopy image of Mn positive control group; k: Electron microscopy image of Ni positive control group; l: Electron microscopy image of Co positive control group.

[0032] Figure 7 EDS analysis of the product manganese carbonate produced by biomineralization. a: Schematic diagram of manganese carbonate biomineralization; b: EDS layered image of manganese; c: EDS analysis of the manganese negative control group; d: EDS analysis of the manganese experimental group; e: EDS analysis of the manganese positive control group.

[0033] Figure 8 EDS analysis of the product nickel carbonate produced by biomineralization. a: Schematic diagram of nickel carbonate biomineralization; b: EDS layered image of nickel; c: EDS analysis of the nickel negative control group; d: EDS analysis of the nickel experimental group; e: EDS analysis of the nickel positive control group. Figure 9 EDS analysis of the product cobalt carbonate produced by biomineralization. a: Schematic diagram of cobalt carbonate biomineralization; b: EDS layered image of cobalt; c: EDS analysis of the cobalt negative control group; d: EDS analysis of the cobalt experimental group; e: EDS analysis of the cobalt positive control group. Detailed implementation mode

[0034] The present invention will be described in detail below in conjunction with specific embodiments.

[0035] Example 1: Construction and expression of recombinant urease Escherichia coli

[0036] Gene construction and cloning: The amino acid sequences of the seven subunits (UreA, UreB, UreC, UreD, UreE, UreF, UreG) of urease from S. pasteurii were retrieved using the UniProt database and codon-optimized to obtain a highly efficient urease gene sequence suitable for expression in E. coli. The optimized gene sequence was divided into two segments: UreA-UreB-UreC and UreE-UreF-UreG-UreD, which were cloned into the pET28a and pET21a plasmids with a T7 promoter respectively to construct the recombinant plasmids pET28a-UreABC and pET21a-UreEFGD. The recombinant plasmids were synthesized by a professional company (such as Genewiz).

[0037] Construction of recombinant strains: The recombinant plasmids pET28a-UreABC and pET21a-UreEFGD were separately transformed into E. coli BL21(DE3) competent cells. The specific steps are as follows:

[0038] Take 5 μL of plasmid pET28a-UreABC and 5 μL of plasmid pET21a-UreEFGD and add them to 100 μL of competent cells, then incubate on ice for 20 minutes.

[0039] Heat shock at 42°C for 90 seconds, then incubate on ice for 5 minutes.

[0040] Add 1 mL of sterile and antibiotic-free LB liquid medium, and culture with shaking at 37°C and 220 rpm for 1 hour.

[0041] Centrifuge at 13,000 rpm for 1 minute, discard the supernatant, leave 100 μL of resuspension and spread it on an LB solid medium containing 100 μg / mL Amp and 100 μg / mL Kan, then incubate inverted at 37°C overnight.

[0042] Pick a single colony and inoculate it into an LB liquid medium containing 100 μg / mL Amp and 100 μg / mL Kan, culture with shaking at 37°C and 220 rpm overnight to obtain the engineered E. coli E. coli BL21(DE3) / pET28a-UreABC + pET21a-UreEFGD.

[0043] Mix the bacterial solution with 50% glycerol at a ratio of 1:1 and store at -80°C.

[0044] Expression of highly active urease, including the following steps:

[0045] The engineered E. coli E .coli1 mL of the seed culture of BL21(DE3) / pET28a-UreABC + pET21a-UreEFGD was transferred to 50 mL of DYT liquid medium containing 100 μg / mL Amp and 100 μg / mL Kan, and cultured in a shaker at 220 rpm and 37 °C for 2.5 h. The culture was continued until IPTG with a final concentration of 0.5 mM and NiCl 600 with a final concentration of 5 μM were added when OD 2 reached 0.6 - 0.8, and then induction culture was carried out. The culture was continued in a shaker at 220 rpm and 20 °C for 16 h. The bacteria were harvested when OD 600 reached 2.0 - 2.2 to obtain a bacterial solution containing highly active urease.

[0046] Comparative Example 1: The vector p-JUMP was transformed into E .coli BL21(DE3) to prepare the strain E .coli BL21(DE3) / pJUMP as a control group. The preparation method was similar to that of Example 1.

[0047] Comparative Example 2: The vector pET28a-UreABC was transformed into E .coli BL21(DE3) to prepare the strain E .coli BL21(DE3) / pET28a-UreABC. The preparation method was similar to that of Example 1.

[0048] Comparative Example 3: The vector pET21a-UreEFGD was transformed into E .coli BL21(DE3) to prepare the strain E .coli BL21(DE3) / pET21a-UreEFGD. The preparation method was similar to that of Examples 1 - 2.

[0049] Test Example 1: Identification of urease expression

[0050] SDS-PAGE was performed to observe the expression of each urease subunit. The pJUMP double plasmid without urease expression was used as the control group, and the experimental group took the single plasmid pET28a-UreABC and the single plasmid pET21a-UreEFGD as the control and the double plasmid pET28a-UreABC+pET21a-UreEFGD, where the pre-induction period was pre, the post-induction period was post, the whole cell lysate after ultrasound was recorded as SNP, and the supernatant of the whole cell lysate after centrifugation was recorded as SN. Take 1 mL from each of the six tubes of pJUMP pre, dual-plasmid pET28a-UreABC+pET21a-UreEFGD pre, pJUMP, single-plasmid pET28a-UreABC, single-plasmid pET21a-UreEFGD and dual-plasmid pET28a-UreABC+pET21a-UreEFGD post, and centrifuge at 13,000 rpm for 1 min to remove the supernatant. Then, resuspend the two tubes of pre with 500 ul PBS and the four tubes of post with 1 mL PBS. After the six tubes of samples were ultrasonically broken in an ice bath (power setting 75%, supersonication for 2s, stop for 10s, a total of 5min), 40uL of each tube was separated and added to a 1.5ml centrifuge tube with 10uL loading dye for sample preparation, and a total of six groups of samples (corresponding to the SNP of the name); the remaining samples were centrifuged at 13000rpm, 4℃, and 40uL of the supernatant was taken and added to a 1.5mL centrifuge tube with 10uL loading dye for sample preparation (corresponding to the SN of the name). The above 12 tubes of liquid were placed in a 99.9℃ metal bath for 10min. Cool to room temperature. Fix the precast gel on the splint, add buffer to ensure that the inner tank does not leak, remove the precast gel comb, and add MOPS-SDS buffer to the outer tank scale line according to actual needs. Add samples and markers, and start running the gel at 200V, 145mA, and 30W. Stop the reaction when all sample dyes escape and the 10kDa band reaches the bottom. Place the protein gel in a disposable box and add the staining buffer for staining. Heat until it is about to boil, gently shake it in a destaining shaker for 10 minutes, add the destaining buffer and heat it to wash away the excess dye. Repeat this step until all bands can be seen clearly. Figure 2 The red boxes are the bands corresponding to the sizes of each urease subunit. It can be seen that the corresponding bands are darker in color, indicating that the translation expression of each urease subunit is good.

[0051] Test Example 2: Urease activity determination

[0052] Take 10 mL of the double-plasmid pET28a-UreABC + pET21a-UreEFGD bacterial solution and 2 mL of the control group p-JUMP bacterial solution after induction, and centrifuge them at 13,000 rpm for 1 min to obtain the bacterial cells. The bacterial cells are resuspended with 1 mL of lysis buffer. Ultrasonic disruption is carried out in an ice bath (power 300 W, ultrasonic for 3 s, interval 7 s, total time 3 min), then centrifuge at 4°C and 13,000 rpm for 15 min, and take the supernatant and place it on ice for further measurement. Divide the supernatant of each tube into two tubes. One tube is used as the crude enzyme solution, and the other tube is treated in a boiling water bath for 10 min and then cooled to room temperature as the inactivated enzyme solution. The urease (UE) activity detection kit (product number: AKNM003M) is used to complete the quantitative detection of urease activity. The reaction principle is as follows: The NH 3 -N produced by urease hydrolysis of urea can react with hypochlorite and phenol in a strong alkaline medium to form a water-soluble blue dye indophenol blue. The product has a characteristic absorption peak at 630 nm, and the activity of urease can be characterized by the change in absorbance value. Denote the double plasmid of the experimental group as A determination, and the control group p-JUMP as A control. Calculate ∆A determination = A determination - A control. After conversion calculation, the urease activity is shown in Figure 3 . The urease activity can be obtained as 0.153 U / g DCW (U: the amount of enzyme that catalyzes the formation of 1.0 micromole of ammonia per minute at a pH value of 7.0), showing obvious urease activity compared with the control group.

[0053] Example 2 Verification of recombinant urease biomineralization

[0054] Experimental materials:

[0055] (1) Experimental group: Double-plasmid Escherichia coli recombinantly expressing urease E .coli BL21(DE3) / pET28a-UreABC + pET21a-UreEFGD.

[0056] (2) Negative control group: Untransformed Escherichia coli BL21(DE3), used as the negative control group.

[0057] (3) Positive control group: Untransformed Escherichia coli BL21(DE3), added with exogenous urease (10 mg / mL), used as the positive control group.

[0058] Mineralization reaction: The process of preparing the bacterial strains is the same as in Example 1. After induction, the bacterial solutions of the experimental group, negative control group, and positive control group are co-incubated with solutions containing metal ions (Li, Mn, Co, Ni) (concentrations are 0.5 mM, 1.0 mM, 0.2 mM, 0.5 mM respectively) and 10 g / L urea under the condition of pH 8.5 - 9.0, and cultured in a shaker at 37°C and 220 rpm for 24 hours to obtain carbonate minerals corresponding to lithium, manganese, cobalt, and nickel metals.

[0059] Results Observation and Analysis: As Figure 4 , the bacterial solution was spread on a glass slide, and the growth and surface morphology changes of the bacteria were observed with an optical microscope. It can be seen that compared with the BL21(DE3) control group, the double-plasmid experimental group of recombinant urease showed obvious differences in the mineralization of four metal ions, Li, Mn, Co, and Ni, under the optical microscope: it can be seen that the bacteria were significantly agglomerated, and a layer of substance was obviously attached around the bacteria.

[0060] As Figure 5 , the surface morphology of the bacteria was observed with AFM and the height change was measured. It can be seen that the bacteria in the control group were more dispersed and the area around the bacteria was relatively flat, while in the double-plasmid experimental group, most of the bacteria showed an aggregation phenomenon, and there was a height around the bacteria. The AFM observation and analysis confirmed that there were indeed some substances attached around the bacteria.

[0061] As Figures 6 - 9 , the surface morphology of the bacteria was observed with a scanning electron microscope (SEM), and the elemental composition and content on the surface of the bacteria were analyzed with an energy dispersive spectrometer (EDS). The SEM images showed that the surfaces of the Li, Mn, Ni, and Co negative control bacteria were relatively smooth. There were phenomena of swelling at one or both ends on the surfaces of the bacteria in the Li experimental group and the positive control group; the surface of the bacteria in the Mn experimental group showed morphologies of swelling at one end, swelling in a ring in the middle, and swelling at both ends, while the positive control would additionally form two hemispherical carbonate precipitates outside the bacteria; the Ni experimental group showed apparent morphologies of swelling at one end and swelling in the middle on the surface of the bacteria, and the positive control had the same phenomenon; the Co experimental group mostly showed club-shaped swelling at one end and swelling in the middle on the surface of the bacteria, while the mineralization phenomenon on the surface of the bacteria in the positive control group was not obvious. It can be seen from the EDS results that the analysis of the element contents of Mn, Ni, and Co generally showed the result of positive control > experimental group > negative control, proving that the mineralized product was rich in the target metal. Combining the SEM biomineralization diagrams of Li, Mn, Ni, and Co, all these effectively proved that the Escherichia coli with our recombinant urease could successfully carry out mineralization.

[0062] Example 3: Recovery and Application of Mineralized Product

[0063] Collection and Purification of Mineralized Product: After the mineralization reaction was completed, the reaction solution was filtered to collect the Escherichia coli precipitate attached with the mineralized product, and then the precipitate was washed three times with distilled water to remove impurities. The washed precipitate was placed in an environment at 60 °C and dried for 24 hours to obtain lithium carbonate (Li 2 CO 3 ), manganese carbonate (MnCO 3 ), cobalt carbonate (CoCO 3 ), and nickel carbonate (NiCO 3The mineralized product with [main component]. To completely remove the Escherichia coli cells and retain the carbonate minerals, the dried precipitate was calcined at 200 °C for 1 - 2 hours. Within this temperature range, the organic components of the cells were fully oxidized and decomposed, leaving only carbon-based and inorganic carbonate minerals, while avoiding the decomposition of carbonates into carbon dioxide and its escape.

[0064] Purity and recovery rate of the mineralized product: Through atomic absorption spectrometry (AAS) and inductively coupled plasma optical emission spectrometry (ICP-OES) analysis, the purities of lithium, manganese, cobalt, and nickel in the mineralized product were 98.2%, 95.3%, 93.8%, and 96.5% respectively, and the first recovery rates were 94.27%, 89.36%, 71.60%, and 64.44% respectively. After repeated mineralization and recovery, the recovery rates could reach about 90%.

[0065] Application of the mineralized product: The recovered lithium carbonate (Li 2 CO 3 )and cobalt carbonate (CoCO 3 )were successfully used as raw materials to prepare the cathode material of lithium-ion batteries (such as LiCoO 2 ). Through electrochemical performance testing, its key indicators such as cycle stability and capacity retention rate were comparable to those of the materials prepared from commercial raw materials, demonstrating excellent battery performance. At the same time, the recovered nickel carbonate (NiCO 3 )was used to prepare catalysts, showing comparable activity to commercial catalysts in different catalytic reactions and having good stability. These results indicate that the carbonate minerals prepared by mineralization and recovery have broad application potential in the fields of energy storage and catalysis, and their performance can be comparable to that of commercial raw materials.

[0066] Example 4: Mineralization effect of different metal ion concentrations

[0067] Experimental conditions: Recombinant urease Escherichia coli was co-incubated with metal ion solutions at different concentrations (lithium: 0.1 - 1.0 mM, manganese: 0.2 - 2.0 mM, cobalt: 0.05 - 0.5 mM, nickel: 0.1 - 1.0 mM, and 10 gradients were set for each concentration range) under the condition of pH 8.5 - 9.0, cultured at 37 °C and 220 rpm for 24 hours.

[0068] Result analysis: With the increase of metal ion concentration, both the mineralization efficiency and the recovery rate increased significantly. When the lithium ion concentration was 0.5 mM, the recovery rate reached 94.27%; when the manganese ion concentration was 1.0 mM, the recovery rate reached 89.36%; when the cobalt ion concentration was 0.2 mM, the recovery rate reached 71.60%; when the nickel ion concentration was 0.5 mM, the recovery rate reached 64.44%, and after repeated mineralization and recovery, the recovery rates could reach about 90%.

[0069] Example 5: Influence of Different pH Values on Mineralization Effect

[0070] Experimental conditions: The recombinant urease bacteria were co-incubated with a solution containing metal ions (lithium: 0.5 mM, manganese: 1.0 mM, cobalt: 0.2 mM, nickel: 0.5 mM) under different pH values (7.0 - 9.5), and cultured at 37 °C and 220 rpm for 24 hours.

[0071] Result analysis: When the pH value was 8.5 - 9.0, both the mineralization efficiency and the recovery rate reached the highest level. When the pH value was lower than 8.0 or higher than 9.5, the mineralization efficiency decreased significantly.

[0072] It is easy for those skilled in the art to understand that the above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method and application of recycling metals from waste lithium batteries using engineered Escherichia coli biomineralization, characterized in that: The following steps are involved: (1) Divide the efficient urease genes of S. pasteurii into gene modules and construct recombinant plasmids; (2) Transforming the recombinant plasmid into the bacteria, optimizing the induction conditions, including the inducer concentration and nickel ion concentration, to obtain an engineered Escherichia coli that efficiently expresses urease; (3) Adjusting the pH value, incubating the engineered E. coli with a solution containing metal ions such as lithium, manganese, cobalt, and nickel for 24 hours to form corresponding mineralization products; (4) Collect and dry mineral products of metals such as lithium, manganese, cobalt, and nickel.

2. The biomineralization method according to claim 1, characterized in that: The metal ion solution is derived from the leaching solution of waste lithium batteries.

3. The biomineralization method according to claims 1-3, characterized in that: The co-incubation conditions are: 37° C., shaking speed 220 rpm.

4. The method according to claim 1-3 or 1-4, characterized in that: The mineralization products include lithium carbonate (Li2CO3), manganese carbonate (MnCO3), cobalt carbonate (CoCO3) and nickel carbonate (NiCO3).

5. The method according to claim 1, characterized in that The engineered Escherichia coli has a high recovery rate for lithium, manganese, cobalt and nickel.

6. A mineralized product recovered by the method of claim 1, characterized in that: The purity of the minerals is above 90%.

7. The mineralized product according to claim 6, characterized in that The mineralized product can be used to prepare lithium battery positive electrode materials, catalysts or other industrial materials.

8. The dual-plasmid expression system of the method according to claim 1, characterized in that: The following steps are involved: (1) The first gene module, UreABC, contains the UreA, UreB, and UreC genes; (2) The second gene module - UreEFGD, including UreE, UreF, UreG, and UreD genes; (3) The plasmids all carry a T7 promoter and can be efficiently expressed in E. coli BL21 (DE3).

9. An application of the method according to claim 1 in resource utilization of waste lithium batteries, characterized in that: The method is applicable to metal recovery from various battery types, such as lithium-ion batteries, nickel-metal hydride batteries, and lead-acid batteries.

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