A method for modifying a zinc battery electrode and a modified electrode and zinc battery prepared thereby
By preparing an extremely thin solid-like electrolyte layer on the surface of zinc battery electrodes, the dendrite growth problem caused by SEI inhomogeneity in zinc batteries was solved, achieving high-efficiency cycle stability and long lifespan of the battery. The zinc ion deposition was controlled by a modified liquid coating method to form a tightly bonded SEI layer.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ANHUI UNIV
- Filing Date
- 2024-07-31
- Publication Date
- 2026-07-21
Smart Images
Figure CN118983391B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of zinc battery technology, specifically to a method for modifying zinc battery electrodes and the preparation of modified electrodes and zinc batteries. Background Technology
[0002] During the operation of zinc-ion batteries, due to interfacial reactions, a solid electrolyte interface (SEI) ranging from a few nanometers to tens of nanometers in thickness inevitably forms between the zinc anode and the electrolyte. This SEI stabilizes the zinc anode in aqueous or non-aqueous electrolytes, improving the battery's lifespan. However, since dendrite growth, corrosion, and passivation are unavoidable during battery operation, the SEI is always uneven, leading to a vicious cycle of disordered zinc ion deposition and growth, exacerbating dendrite formation. Dendrite tips easily pierce the SEI and continue to form new SEI at the cracks. This irreversible and repeated damage and formation thickens and unevenens the SEI, resulting in battery capacity loss, increased resistance, metal anode corrosion, poor cycle stability, and low coulombic efficiency.
[0003] Based on this, various strategies have been proposed to promote the formation and optimization of SEI films, modulate the electrode / electrolyte interface to suppress hydrogen evolution reaction and corrosion, reduce dendrite growth, and extend battery life and electrochemical stability window, such as adding organic / inorganic additives or artificial coatings. However, with the addition of organic / inorganic additives, the in-situ formation process of SEI during battery cycling is uncontrollable, so its structure, composition, and thickness cannot be directly adjusted. Furthermore, in-situ grown SEI layers are highly sensitive to air, water vapor, and carbon dioxide; when they leave the original liquid electrolyte, their stable state is disrupted, and their composition and thickness undergo irreversible changes. Therefore, analysis and characterization must be performed under vacuum conditions, which places very high demands on the detection environment. Due to these characterization limitations, there are currently no definitive conclusions regarding the structure of in-situ SEIs.
[0004] The most common method for preparing artificial SEIs is to fabricate a protective layer on the negative electrode surface. However, when using a blade for scraping and coating, it is difficult to control the coating thickness and achieve a flat surface. While spin coating can control the coating thickness, centrifugal force cannot guarantee a uniform composition. Electrospinning only shows coating uniformity at a macroscopic level; the bond between the protective layer and the substrate remains weak. Furthermore, the protective layers prepared using these methods are mostly in the micrometer range, making nanoscale control difficult, which increases interfacial resistance and further reduces energy density. Summary of the Invention
[0005] The technical problem to be solved by this invention is how to prepare an extremely thin solid-like electrolyte layer in an electrode, and to clarify its structural composition in order to reduce the interfacial resistance.
[0006] The present invention solves the above-mentioned technical problems through the following technical means:
[0007] The first aspect of this invention provides a method for modifying a zinc battery electrode, comprising the following steps:
[0008] (1) Preparation of modified liquid: The cationic acceptor monomer is dissolved in a solvent, and a crosslinking agent and an initiator are added to it to obtain the modified liquid, wherein the cationic acceptor monomer is an amino derivative of an unsaturated ester;
[0009] (2) The modified liquid is coated on the electrode surface to carry out a polymerization reaction, and the modified electrode is obtained after the reaction.
[0010] Beneficial effects: The inventors have constructed a solid-state electrolyte layer (SEI), defined the composition of the SEI layer, and ensured that the solid-state electrolyte layer is closely connected to the electrode. Furthermore, the invention can improve the kinetic adsorption and mass transfer flux of zinc ions, effectively suppress hydrogen evolution reaction and the generation of zinc dendrites, and achieve battery reversibility and ultra-long cycle life.
[0011] Preferably, the cationic acceptor monomer is dimethylaminoethyl methacrylate.
[0012] Preferably, the solvent is water; the crosslinking agent is N,N-methylenebisacrylamide.
[0013] Preferably, the initiator is one of azobisisobutyrazoline hydrochloride, potassium persulfate, and ammonium persulfate.
[0014] Preferably, the polymerization reaction is a free radical polymerization.
[0015] Preferably, the mass concentration of the cationic acceptor monomer in the modified solution is 5-30 mg / ml.
[0016] Beneficial effects: This invention regulates the mass concentration of the cation acceptor monomer, thereby controlling the thickness of the solid electrolyte layer (SEI) coated on the zinc anode, making the solid electrolyte layer only tens of nanometers. By utilizing the advantages of the differences in binding force and migration deposition rate of zinc ions caused by different N atom concentrations at different thicknesses, the optimal overpotential for uniform zinc ion deposition was determined, and a highly reversible aqueous zinc-ion battery was constructed.
[0017] Preferably, the molar ratio of the cation acceptor monomer: crosslinking agent: initiator is 1: 2% of the molar number of the cation acceptor monomer double bond: 2% of the molar number of the cation acceptor monomer double bond.
[0018] Preferably, the coating method employs a drop-coating-standing-reabsorption method.
[0019] The second aspect of the present invention provides a modified electrode prepared by the above-described zinc battery electrode modification method.
[0020] A third aspect of the present invention provides a zinc battery, comprising a modified electrode prepared by the above-described zinc battery electrode modification method.
[0021] The advantages of this invention are:
[0022] This invention artificially constructs a solid-state electrolyte layer (SEI) for zinc electrodes with a thickness of only tens of nanometers and a simple fabrication process. By utilizing the varying thickness of the SEI and the resulting different nitrogen atom concentrations, the binding force on zinc ions varies, leading to different migration rates during the zinc ion deposition and dissolution process. Batteries fabricated at the optimal migration rate perfectly suppress hydrogen evolution reaction and zinc dendrite growth, ultimately resulting in zinc batteries with an extremely thin, well-defined, and tightly bonded SEI layer to the electrode. Attached Figure Description
[0023] Figure 1 The zinc batteries prepared in Examples 1-4 and Comparative Example 1 are at 1 mA cm -2 and 1mAh cm -2 Long-cycle performance under test conditions;
[0024] Figure 2 The zinc batteries prepared in Examples 1-4 and Comparative Example 1 were tested at 10 mA cm⁻¹. -2 and 10mAh cm -2 Long-cycle performance under test conditions;
[0025] Figure 3 The zinc batteries prepared in Example 2 and Comparative Example 1 were tested at 1 mA cm⁻¹. -2 and 1mAh cm -2 SEM image after 50 cycles under test conditions;
[0026] Figure 4 The zinc batteries prepared in Examples 5-8 and Comparative Example 2 are tested at 1 mA cm⁻¹. -2 Coulomb efficiency curve under test conditions;
[0027] Figure 5 This is a FIB-SEM image of the zinc electrode prepared in Example 2, which characterizes the thickness of the solid-like electrolyte layer.
[0028] In the diagram, Bare Zn represents an unmodified zinc electrode. Detailed Implementation
[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0030] Unless otherwise specified, all test materials and reagents used in the following examples are commercially available.
[0031] Unless otherwise specified in the embodiments, the techniques or conditions described in the literature in this field or in accordance with the product manual may be followed.
[0032] Example 1
[0033] This embodiment provides a method for modifying a zinc battery electrode, a modified zinc electrode, and a zinc battery, specifically including the following steps:
[0034] (1) Preparation of the modified liquid:
[0035] Dissolve 0.5g of dimethylaminoethyl methacrylate in 100ml of water to obtain a 5mg / ml dimethylaminoethyl methacrylate solution. Then add 10mg of N,N-methylenebisacrylamide and 20mg of azobisisobutyrazoline hydrochloride to the solution and stir for 1 hour to obtain the modified solution.
[0036] (2) Preparation of modified zinc electrode:
[0037] In this embodiment, zinc foil discs with a diameter of 12 mm and a thickness of 100 μm are used. The zinc foil discs are treated with 1M hydrochloric acid to remove surface oxides, and then subjected to multiple ultrasonic cleanings in water before being dried for later use.
[0038] The modified liquid was applied to the surface of the treated zinc foil disc by drop application, and allowed to stand for 15 minutes to allow the modified liquid to fully contact the zinc foil disc. Then, excess liquid was absorbed.
[0039] A zinc foil disc coated with 5 mg / ml of the modifying solution was placed in a closed device and purged with nitrogen for 15 min. Free radical polymerization was carried out at 65 °C under a nitrogen atmosphere for 3 hours to obtain a modified zinc electrode (Zn@PDM5) loaded with poly(dimethylaminoethyl methacrylate).
[0040] (3) Preparation of zinc batteries:
[0041] A CR2032 symmetrical battery was assembled using a modified zinc electrode as the positive and negative electrodes, glass fiber as the battery separator, and a 2M zinc sulfate aqueous solution as the electrolyte.
[0042] Example 2
[0043] This embodiment provides a zinc battery electrode modification method, a modified zinc electrode, and a zinc battery. The difference between this embodiment and Embodiment 1 is that step (1) is as follows:
[0044] (1) Preparation of the modified liquid:
[0045] Dissolve 1.0 g of dimethylaminoethyl methacrylate in 100 ml of water to obtain a 10 mg / ml dimethylaminoethyl methacrylate solution. Then add 20 mg of N,N-methylenebisacrylamide and 40 mg of azobisisobutyrazoline hydrochloride to the solution and stir for 1 hour to obtain the modified solution.
[0046] Steps (2) and (3) are exactly the same as in the example, yielding a modified zinc electrode (Zn@PDM). 10 ).
[0047] Example 3
[0048] This embodiment provides a zinc battery electrode modification method, a modified zinc electrode, and a zinc battery. The difference between this embodiment and Embodiment 1 is that step (1) is as follows:
[0049] (1) Preparation of the modified liquid:
[0050] Dissolve 2.0 g of dimethylaminoethyl methacrylate in 100 ml of water to obtain a 20 mg / ml dimethylaminoethyl methacrylate solution. Then add 40 mg of N,N-methylenebisacrylamide and 80 mg of azobisisobutyrazoline hydrochloride to the solution and stir for 1 hour to obtain the modified solution.
[0051] Steps (2) and (3) are exactly the same as in the example, yielding a modified zinc electrode (Zn@PDM). 20 ).
[0052] Example 4
[0053] This embodiment provides a zinc battery electrode modification method, a modified zinc electrode, and a zinc battery. The difference between this embodiment and Embodiment 1 is that step (1) is as follows:
[0054] (1) Preparation of the modified liquid:
[0055] Dissolve 3.0 g of dimethylaminoethyl methacrylate in 100 ml of water to obtain a 30 mg / ml dimethylaminoethyl methacrylate solution. Then add 60 mg of N,N-methylenebisacrylamide and 120 mg of azobisisobutyrazoline hydrochloride to the solution and stir for 1 hour to obtain the modified solution.
[0056] Steps (2) and (3) are exactly the same as in the example, modified zinc electrode (Zn@PDM) 30 ).
[0057] Example 5
[0058] This embodiment provides a method for modifying a zinc battery electrode, a modified zinc electrode, a modified copper electrode, and a zinc-copper half-cell, specifically including the following steps:
[0059] (1) Preparation of the modified liquid:
[0060] Dissolve 0.5g of dimethylaminoethyl methacrylate in 100ml of water to obtain a 5mg / ml dimethylaminoethyl methacrylate solution. Then add 10mg of N,N-methylenebisacrylamide and 20mg of azobisisobutyrazoline hydrochloride to the solution and stir for 1 hour to obtain the modified solution.
[0061] (2) Preparation of modified electrodes:
[0062] In this embodiment, zinc foil discs with a diameter of 12 mm and a thickness of 100 μm are used. The zinc foil discs are treated with 1M hydrochloric acid to remove surface oxides, and then subjected to multiple ultrasonic cleanings in water before being dried for later use.
[0063] In this embodiment, a copper foil disc with a diameter of 12 mm and a thickness of 20 μm is used. The copper foil disc is polished with sandpaper to remove surface oxides, and then placed in ethanol for multiple ultrasonic cleanings before being dried for later use.
[0064] The modified liquid was applied to the surface of the treated zinc foil and copper foil discs by drop application. After standing for 15 minutes, the modified liquid was allowed to fully contact the zinc foil and copper foil discs, and then the excess liquid was absorbed.
[0065] Zinc and copper foil discs coated with 5 mg / ml modification solution were placed in a closed device and purged with nitrogen for 15 min. Free radical polymerization was carried out at 65 °C under a nitrogen atmosphere for 3 hours to obtain modified zinc electrode (Zn@PDM5) and modified copper electrode (Cu@PDM5) loaded with poly(dimethylaminoethyl methacrylate).
[0066] (3) Preparation of zinc-copper half-cell:
[0067] A CR2032 type Zn / Cu half-cell was assembled using a modified zinc electrode as the negative electrode, a modified copper electrode as the positive electrode, glass fiber as the battery separator, and a 2M zinc sulfate aqueous solution as the electrolyte.
[0068] Example 6
[0069] This embodiment provides a method for modifying a zinc battery electrode, a modified zinc electrode, a modified copper electrode, and a zinc-copper half-cell, specifically including the following steps:
[0070] The difference between this embodiment and embodiment 5 is that step (1) is as follows:
[0071] (1) Preparation of the modified liquid:
[0072] Dissolve 1.0 g of dimethylaminoethyl methacrylate in 100 ml of water to obtain a 10 mg / ml dimethylaminoethyl methacrylate solution. Then add 20 mg of N,N-methylenebisacrylamide and 40 mg of azobisisobutyrazoline hydrochloride to the solution and stir for 1 hour to obtain the modified solution.
[0073] Steps (2) and (3) are exactly the same as in the example, yielding a modified zinc electrode (Zn@PDM). 10 ) and modified copper electrode (Cu@PDM) 10 ).
[0074] Example 7
[0075] This embodiment provides a method for modifying a zinc battery electrode, a modified zinc electrode, a modified copper electrode, and a zinc-copper half-cell, specifically including the following steps:
[0076] The difference between this embodiment and embodiment 5 is that step (1) is as follows:
[0077] (1) Preparation of the modified liquid:
[0078] Dissolve 2.0 g of dimethylaminoethyl methacrylate in 100 ml of water to obtain a 20 mg / ml dimethylaminoethyl methacrylate solution. Then add 40 mg of N,N-methylenebisacrylamide and 80 mg of azobisisobutyrazoline hydrochloride to the solution and stir for 1 hour to obtain the modified solution.
[0079] Steps (2) and (3) are exactly the same as in the example, yielding a modified zinc electrode (Zn@PDM). 20 ) and modified copper electrode (Cu@PDM) 20 ).
[0080] Example 8
[0081] This embodiment provides a method for modifying a zinc battery electrode, a modified zinc electrode, a modified copper electrode, and a zinc-copper half-cell, specifically including the following steps:
[0082] The difference between this embodiment and embodiment 5 is that step (1) is as follows:
[0083] (1) Preparation of the modified liquid:
[0084] Dissolve 3.0 g of dimethylaminoethyl methacrylate in 100 ml of water to obtain a 30 mg / ml dimethylaminoethyl methacrylate solution. Then add 60 mg of N,N-methylenebisacrylamide and 120 mg of azobisisobutyrazoline hydrochloride to the solution and stir for 1 hour to obtain the modified solution.
[0085] Steps (2) and (3) are exactly the same as in the example, yielding a modified zinc electrode (Zn@PDM). 30 ) and modified copper electrode (Cu@PDM) 30 ).
[0086] Example 9
[0087] This embodiment provides a zinc battery electrode modification method, a modified zinc electrode, and a zinc battery. The difference between this embodiment and Embodiment 1 is that step (1) is as follows:
[0088] (1) Preparation of the modified liquid:
[0089] Dissolve 0.5g of dimethylaminoethyl methacrylate in 100ml of water to obtain a 5mg / ml dimethylaminoethyl methacrylate solution. Then add 10mg of N,N-methylenebisacrylamide and 17mg of potassium persulfate to the solution and stir for 1 hour to obtain the modified solution.
[0090] Steps (2) and (3) are exactly the same as in the example to obtain the modified zinc electrode (Zn@PDM5).
[0091] Example 10
[0092] This embodiment provides a zinc battery electrode modification method, a modified zinc electrode, and a zinc battery. The difference between this embodiment and Embodiment 1 is that step (1) is as follows:
[0093] (1) Preparation of the modified liquid:
[0094] Dissolve 0.5g of dimethylaminoethyl methacrylate in 100ml of water to obtain a 5mg / ml dimethylaminoethyl methacrylate solution. Then add 10mg of N,N-methylenebisacrylamide and 15mg of ammonium persulfate to the solution and stir for 1 hour to obtain the modified solution.
[0095] Steps (2) and (3) are exactly the same as in the example to obtain the modified zinc electrode (Zn@PDM5).
[0096] Example 11
[0097] This embodiment provides a zinc battery electrode modification method, a modified zinc electrode, and a zinc battery. The difference between this embodiment and Embodiment 1 is that step (1) is as follows:
[0098] (1) Preparation of the modified liquid:
[0099] Dissolve 2g of dimethylaminoethyl methacrylate in 100ml of water to obtain a 20mg / ml dimethylaminoethyl methacrylate solution. Then add 40mg of N,N-methylenebisacrylamide and 68mg of potassium persulfate to the solution and stir for 1 hour to obtain the modified solution.
[0100] Steps (2) and (3) are exactly the same as in the example, yielding a modified zinc electrode (Zn@PDM). 20 ).
[0101] Example 12
[0102] This embodiment provides a zinc battery electrode modification method, a modified zinc electrode, and a zinc battery. The difference between this embodiment and Embodiment 1 is that step (1) is as follows:
[0103] (1) Preparation of the modified liquid:
[0104] Dissolve 3g of dimethylaminoethyl methacrylate in 100ml of water to obtain a 30mg / ml dimethylaminoethyl methacrylate solution. Then add 60mg of N,N-methylenebisacrylamide and 102mg of potassium persulfate to the solution and stir for 1 hour to obtain the modified solution.
[0105] Steps (2) and (3) are exactly the same as in the example, yielding a modified zinc electrode (Zn@PDM). 30 ).
[0106] Comparative Example 1
[0107] Zinc foil discs with a diameter of 12 mm and a thickness of 100 μm were treated with 1M hydrochloric acid to remove surface oxides, and then subjected to multiple ultrasonic cleanings in water before being dried for later use. The zinc foil discs were then used as the positive and negative electrodes, glass fiber as the battery separator, and a 2M zinc sulfate aqueous solution as the electrolyte to assemble a CR2032 type symmetrical battery.
[0108] Comparative Example 2
[0109] Zinc foil discs with a diameter of 12 mm and a thickness of 20 μm were treated with 1M hydrochloric acid to remove surface oxides, then subjected to multiple ultrasonic cleanings in water, and subsequently dried for later use. Copper foil discs with a diameter of 12 mm and a thickness of 20 μm were polished with sandpaper to remove surface oxides, then subjected to multiple ultrasonic cleanings in ethanol, and subsequently dried for later use. A CR2032 type Zn / Cu half-cell was assembled using the zinc foil discs as the negative electrode, the copper foil discs as the positive electrode, glass fiber as the battery separator, and a 2M zinc sulfate aqueous solution as the electrolyte.
[0110] fromFigure 1 and Figure 2 It can be seen that the symmetric cells assembled using modified zinc electrodes in Examples 1-4 all exhibit better cycle performance than the symmetric cells assembled using unmodified zinc electrodes in Comparative Example 1. Among them, the polymethacrylic acid film prepared by coating with 10 mg / ml of the modified solution provides the best protection for the zinc anode, achieving optimal performance at 1 mA cm⁻¹. -2 Current density and 1mAh cm -2 It exhibits a cycle life exceeding 1600 hours at a surface density of [value missing], and at 10 mA cm [value missing]. -2 Current density and 10mAh cm -2 It has a cycle life of over 1000 hours at a given areal density.
[0111] Figure 3 The SEM images show that the PDM coating 10 The zinc foil layer after the coating is smoother and flatter. In contrast, bare zinc foil has a large number of zinc dendrites on its surface, with disordered deposition orientation, which further grow into sharp flakes, seriously affecting battery performance and safety. Using Zn@PDM 10 No obvious dendrites were observed on the electrode surface because the appropriate overpotential led to a more uniform and denser zinc deposition, thereby suppressing the formation of zinc dendrites.
[0112] Figure 4 The Coulomb efficiency plot shows that at a current density of 1 mA cm⁻¹ -2 In this case, batteries prepared using this modified liquid system are superior to those prepared with bare zinc electrodes, exhibiting more than four times the cycle life, with Zn@PDM being the most suitable. 10 Electrode optimization. From Zn@PDM 10 The battery assembled from the electrodes provides a stable coulombic efficiency of 99.6% over a long period of time and has a cycle life of up to 1700 times, which fully demonstrates that this system has good zinc plating / stripping reversibility.
[0113] Figure 5 The FIB-SEM image clearly characterizes the thickness of the solid-like electrolyte layer. The image shows a thin layer, approximately 60 nm thick, between the Zn and Pt / C protective layers, indicating the successful fabrication of an extremely thin solid-like electrolyte layer, only tens of nanometers thick, on the zinc electrode.
[0114] The comparison between the examples and the comparative examples shows that the good cycle performance, surface morphology and coulombic efficiency prove that the solid-like electrolyte layer helps N atoms to regulate the migration flux and deposition direction of zinc ions at the interface on the negative electrode surface, effectively suppressing the generation of zinc dendrites and by-products, and extending the battery life.
[0115] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for modifying a zinc battery electrode, characterized in that, Includes the following steps: (1) Preparation of modified solution: The cationic acceptor monomer is dissolved in a solvent, and a crosslinking agent and an initiator are added to it to obtain the modified solution. The cationic acceptor monomer is dimethylaminoethyl methacrylate, and the mass concentration of the cationic acceptor monomer in the modified solution is 5-30 mg / ml. (2) The modified liquid is coated on the electrode surface by the method of drop-coating-standing-reabsorption. A solid electrolyte layer with a thickness of tens of nanometers is formed on the electrode surface through polymerization reaction to obtain the modified electrode.
2. The zinc battery electrode modification method according to claim 1, characterized in that, When the mass concentration of the cationic acceptor monomer in the modified solution is 10 mg / ml, the thickness of the solid-like electrolyte layer is 60 nm.
3. The zinc battery electrode modification method according to claim 1, characterized in that, The solvent is water; the crosslinking agent is N,N-methylenebisacrylamide.
4. The zinc battery electrode modification method according to claim 1, characterized in that, The initiator is one of azobisisobutyrazoline hydrochloride, potassium persulfate, and ammonium persulfate.
5. The zinc battery electrode modification method according to claim 1, characterized in that, The polymerization reaction is a free radical polymerization.
6. The zinc battery electrode modification method according to claim 1, characterized in that, The molar ratio of the cationic acceptor monomer, cross-linking agent, and initiator is 1:0.02:0.
02.
7. A modified electrode is prepared by a zinc battery electrode modification method according to any one of claims 1-6.
8. A zinc battery, characterized in that, The modified electrode is prepared by the zinc battery electrode modification method as described in any one of claims 1-6.