An aqueous electrolyte for high-rate tin metal anode and tin-manganese battery

Abstract

The present invention belongs to the field of electrochemical cell technology, and specifically relates to an aqueous electrolyte that can be used for high-rate tin metal negative electrodes and tin-manganese batteries. The aqueous electrolyte includes an acidic solvent, a tin salt, and various high-valent metal salts / charged water-soluble polymers, and may also include a manganese salt. The present invention adds high-valent metal salts / charged water-soluble polymers to the aqueous electrolyte, and uses the introduced charged particles to adjust the double layer repulsion force, homogenize the electric field and concentration field distribution at the interface, thereby achieving efficient ion transport and uniform and dense tin deposition behavior. At the same time, these charged particles can also effectively suppress related side reactions on the manganese positive electrode side, so that the tin metal negative electrode and the tin-manganese battery can have both a long cycle life and excellent rate performance. In addition, the raw materials involved in the aqueous electrolyte are low in price, small in amount, and the reaction process is simple and mild, and it has good application and development prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of electrochemical batteries, and in particular relates to an aqueous electrolyte that can be used for high-rate tin metal negative electrodes and tin-manganese batteries. Background Art

[0002] With the continuous growth of the population, the rapid decline of natural resource reserves, and the ongoing global energy transition, the use of clean energy to replace traditional fossil fuels has become a global consensus. However, the high degree of dispersion and instability of clean energy has severely reduced the possibility of large-scale practical application. Therefore, the development of large-scale energy storage systems that can efficiently utilize clean energy has become crucial.

[0003] Rechargeable secondary batteries are important energy storage systems that utilize clean energy and have broad application prospects. They can be roughly divided into three systems: battery systems using non-aqueous electrolytes, aqueous electrolytes, and solid / quasi-solid electrolytes. Compared with the other two systems, aqueous batteries using aqueous electrolytes have higher safety and good ion transmission capabilities because water is the main solvent, and are considered to be more promising devices for large-scale energy storage in the future. Considering the gas production problem caused by the decomposition of water itself, tin metal negative electrodes have a high hydrogen evolution potential and a suitable theoretical capacity (451.6 mAh g -1 ) and low Young's modulus (42GP) and are widely used in aqueous batteries, especially in acidic environments. However, the tetragonal crystal structure of tin metal and the similar surface energy of each crystal face lead to the formation of large tin particles during the deposition process, and it is very easy to fall off from the substrate during the cycle and turn into "dead tin" with no reaction activity. This greatly reduces the reversibility and stability of tin metal, making it difficult to meet the high requirements of grid-level energy storage. In response to the complex problems faced by tin metal anodes, researchers have proposed various strategies to improve the reversibility of tin metal. For example, the team of Professor Xia Yongyao of Fudan University [Yu Z, Wang Q, Li Y, et al. Highly reversible tin redox chemistry for stable anode-free acidic protonbattery [J]. Joule, 2024, 8, 1063.] reported a composite electrolyte (3 mol / L sulfuric acid + 0.2 mol / L tin sulfate + 1 g·L -1Gelatin), the electrolyte can reduce the exchange current density and increase the polarization of the battery, thereby achieving ordered tin deposition. The team of Professor Lu Xihong of Sun Yat-sen University [Xu D, Zhang H, Xie J, et al. Highly Reversible Tin Film Anode Guided via Interfacial Coordination Effect for High Energy Aqueous Acidic Batteries [J]. Advanced Materials, 2024, 36, 2408067.] reported an electrolyte additive with a long chain (4-trioctylphenol pentaethoxylate), which can adjust the solvent sheath structure of tin ions and increase the nucleation overpotential, thereby achieving small-sized tin particle deposition. The above research results show that it is a desirable and effective strategy to reduce the size of tin particles and thus improve their reversibility by modifying the electrolyte.

[0004] However, most current electrolyte modification methods rely mainly on mixing organic solvents or adding organic molecules to improve the performance of tin anodes. Although the tin particle size is reduced, the battery polarization also increases, which limits the ion transport capacity and leads to a decrease in rate performance. In addition, the uneven distribution of tin ions and the disordered tin deposition sites will also affect the overall performance of the battery. Therefore, in order to develop aqueous tin metal batteries with high reversibility, high rate and high stability to achieve large-scale energy storage, it is necessary to design an aqueous electrolyte that can both regulate the tin deposition behavior and ensure efficient ion transport capabilities. Summary of the Invention

[0005] In order to overcome the deficiencies of the above-mentioned prior art, the present invention provides an aqueous electrolyte that can be used for high-rate tin metal negative electrodes and tin-manganese batteries, which uses metal salts with high-valent ions / charged water-soluble polymers as additives. Due to the charge of the additives, these charged particles can act as competing ions to regulate the double-layer repulsion, thereby effectively accelerating ion transport. At the same time, these charged particles can also homogenize the electric field distribution and tin ion concentration distribution at the interface to achieve dense and uniform tin deposition. In addition, the charged particles can also effectively alleviate the related side reactions on the manganese positive electrode side to achieve high-rate and long-life tin-manganese batteries.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] The first aspect of the present invention provides an aqueous electrolyte that can be used for high-rate tin metal negative electrodes and tin-manganese batteries. The aqueous electrolyte includes an acidic solution, a tin salt, and a high-valent metal salt, or includes an acidic solution, a tin salt, a manganese salt, and a high-valent metal salt; the high-valent metal salt includes indium sulfate, gallium sulfate, aluminum sulfate, chromium sulfate, iron sulfate, lanthanum sulfate, cerium sulfate, titanium sulfate, cobalt sulfate, nickel sulfate, lead sulfate, cadmium sulfate, zinc sulfate, copper sulfate, and magnesium sulfate.

[0008] Preferably, the aqueous electrolyte further comprises a charged water-soluble polymer, and the charged water-soluble polymer comprises polyamine, polyquaternary ammonium salt, polyacrylic acid copolymer, polycarboxylate ether, ionic polyacrylamide, and ionic polyurethane.

[0009] The present invention adds a high-valent metal salt / charged water-soluble polymer to an aqueous electrolyte, uses the introduced charged particles to adjust the double-layer repulsion, and homogenizes the electric field and concentration field distribution at the interface, thereby achieving efficient ion transport and uniform and dense tin deposition behavior. At the same time, these charged particles can also effectively suppress related side reactions on the manganese positive electrode side, so that the tin metal negative electrode and the tin-manganese battery can simultaneously have a long cycle life and excellent rate performance. In addition, the raw materials involved in the aqueous electrolyte are low in price, small in amount, and the reaction process is simple and mild, which has good application and development prospects.

[0010] Preferably, the tin salt includes tin sulfate, tin chloride, tin bromide, tin iodide, tin fluoride, tin oxalate, tin fluorophosphate, tin pyrophosphate, tin trifluoromethanesulfonate, tin tetrafluoroborate, tin nitrate, and tin acetate.

[0011] Preferably, the acidic solution comprises sulfuric acid, hydrochloric acid, nitric acid, bromic acid, iodic acid, hydrofluoric acid, oxalic acid, phosphoric acid, diphosphoric acid, trifluoromethanesulfonic acid, tetrafluoroboric acid, nitric acid, or acetic acid.

[0012] Preferably, the manganese salt includes manganese sulfate, manganese chloride, manganese nitrate, manganese bromide, manganese iodide, manganese tin fluoride, manganese oxalate, manganese phosphate, manganese hydrogen phosphate, manganese dihydrogen phosphate, manganese trifluoromethanesulfonate, manganese nitrate, and manganese acetate.

[0013] Preferably, the concentration of the tin salt is in the range of 0.01 mol / L-1 mol / L; the acidic solution is a mixture of acid and water, and the concentration range is 0.1 mol / L-3 mol / L; the concentration range of the high-valent metal salt is 0.01 mol / L-1 mol / L.

[0014] More preferably, the volume of the charged water-soluble polymer accounts for 0.01%-1% of the total electrolyte volume.

[0015] The second aspect of the present invention provides the use of the aqueous electrolyte described in the first aspect in the preparation of an aqueous battery, wherein the aqueous battery includes a tin symmetrical battery, a tin asymmetrical battery or a tin-manganese battery.

[0016] Preferably, the tin symmetrical battery or the tin asymmetrical battery is assembled by coupling tin foil and metal foil.

[0017] Preferably, the tin-manganese battery is assembled by coupling tin foil and a positive electrode current collector.

[0018] More preferably, the thickness of the tin foil mainly ranges from 50 μm to 200 μm.

[0019] More preferably, the main materials of the metal foil include tin foil, copper foil, titanium foil, and aluminum foil, preferably tin foil and copper foil.

[0020] More preferably, the main material of the positive electrode current collector includes carbon felt, carbon paper, graphite paper, stainless steel mesh, copper foil, aluminum foil, titanium mesh, preferably carbon felt.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] (1) The present invention adds metal salts of high-valent ions / charged water-soluble polymers to the aqueous electrolyte. When applied to tin metal negative electrodes and tin-manganese batteries, the unique charge properties of these additives can not only homogenize the distribution of electric and concentration fields at the interface, but also effectively regulate the repulsive force of the double electric layer. Therefore, this characteristic can enable tin metal negative electrodes and tin-manganese batteries to achieve rapid, uniform and dense tin deposition behavior and obtain excellent rate performance (30 mA cm -2 ), ultra-high Coulombic efficiency (99.96%) and ultra-long cycle life (7187 hours).

[0023] (2) The tin salt involved in the aqueous electrolyte of the present invention is economical and affordable, the concentration / proportion of the additives used is low, the process required to configure the electrolyte is simple, the reaction conditions are mild, the reaction time is short, and it is easy to prepare and store in large quantities. At the same time, the aqueous electrolyte can be used not only on tin metal negative electrodes, but also on other metal negative electrodes (such as copper foil, magnesium foil, indium foil, titanium foil, nickel foil, chromium foil, aluminum foil, etc.), metal powders (such as tin powder, indium powder, copper powder, magnesium powder, tungsten powder, chromium powder, germanium powder, cadmium powder, etc.), positive and negative electrode materials (such as MXene, manganese oxide compounds, vanadium oxide compounds, halogen elements, halides, etc.), etc., and has good application and development prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 1 is the Tafel plot of the tin metal negative electrode in Comparative Example 1 and Example 1.

[0025] Figure 2This is a scanning electron microscope image of the tin metal negative electrode in Comparative Example 1 after cycling.

[0026] Figure 3 This is a scanning electron microscope image of the tin metal negative electrode in Example 1 after cycling.

[0027] Figure 4 This is a rate cycling curve of the symmetrical battery prepared with tin metal negative electrode in Comparative Example 1.

[0028] Figure 5 This is a rate cycling curve of the symmetrical battery prepared with a tin metal negative electrode in Example 1.

[0029] Figure 6 The asymmetric battery prepared with tin metal negative electrode in Comparative Example 1 and Example 1 was tested at a current density of 10 mA·cm -2 , the deposition surface capacity is 1 mAh·cm -2 The cycle performance diagram below.

[0030] Figure 7 Graphs showing the electrochemical performance of the tin-manganese battery prepared with tin metal negative electrodes at different currents in Comparative Example 1 and Example 1.

[0031] Figure 8 The surface capacity-voltage curves of the tin-manganese battery prepared with a tin metal negative electrode in Comparative Example 1 at different currents.

[0032] Figure 9 1 is the surface capacity-voltage curve of the tin-manganese battery prepared with the tin metal negative electrode at different currents in Example 1.

[0033] Figure 10 The tin-manganese battery prepared with tin metal negative electrode in Comparative Example 1 and Example 1 was heated to a current density of 30 mA·cm -2 Long cycle performance diagram when . DETAILED DESCRIPTION

[0034] The following is a further description of specific embodiments of the present invention. It should be noted that the description of these embodiments is intended to facilitate understanding of the present invention and does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0035] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are commercially available unless otherwise specified.

[0036] Example 1

[0037] This embodiment provides a method for preparing an aqueous electrolyte that can be used for high-rate tin metal anodes and tin-manganese batteries. The detailed steps of the method are as follows:

[0038] (1) Weigh 17.18 g of tin sulfate and place it in a beaker. Add 400 mL of 2 mol / L sulfuric acid and stir until evenly to obtain a 0.2 mol / L tin sulfate electrolyte.

[0039] (2) Take 200 mL of the tin sulfate electrolyte of step (1), add 5.18 g of indium sulfate thereto, and stir evenly to obtain the aqueous electrolyte for high-rate tin metal negative electrode of Example 1.

[0040] (3) Take 100 mL of the aqueous electrolyte of step (2), add 30.2 g of manganese sulfate thereto, and stir until the mixture is evenly stirred to obtain the aqueous electrolyte for high-rate tin-manganese battery of Example 1.

[0041] The electrolyte in step (2) is placed together with two pieces of tin metal and a diaphragm in a 2032 button cell for coupling, thereby obtaining the symmetrical battery of Example 1. The electrolyte in step (2) is placed together with a piece of tin metal, a piece of copper foil and a diaphragm in a 2032 button cell for coupling, thereby obtaining the asymmetrical battery of Example 1. The electrolyte in step (3) is placed together with a piece of tin metal and a piece of carbon felt positive electrode current collector in an electrolytic cell for coupling, thereby obtaining the tin-manganese battery of Example 1.

[0042] Comparative Example 1

[0043] This comparative example provides a method for preparing a tin metal negative electrode and an aqueous electrolyte for a tin-manganese battery. The detailed steps of the method are as follows:

[0044] (1) Weigh 17.18 g of tin sulfate and place it in a beaker. Add 400 mL of 2 mol / L sulfuric acid and stir until evenly mixed to obtain the aqueous electrolyte of the tin metal negative electrode of Comparative Example 1.

[0045] (2) Take 100 mL of the aqueous electrolyte of step (1), add 30.2 g of manganese sulfate thereto, and stir until the mixture is evenly stirred to obtain the aqueous electrolyte of the tin-manganese battery of Comparative Example 1.

[0046] The electrolyte in step (1) is placed together with two pieces of tin metal and a diaphragm in a 2032 button cell for coupling, thereby obtaining the symmetrical battery of Comparative Example 1. The electrolyte in step (1) is placed together with a piece of tin metal, a piece of copper foil and a diaphragm in a 2032 button cell for coupling, thereby obtaining the asymmetrical battery of Comparative Example 1. The electrolyte in step (2) is placed together with a piece of tin metal and a piece of carbon felt positive electrode current collector in an electrolytic cell for coupling, thereby obtaining the tin-manganese battery of Comparative Example 1.

[0047] Figure 1 The scanning speed of the tin metal negative electrode in the three-electrode system is 1 mV·s -1 The Tafel plot at the time. Figure 1 As can be seen from the results, the corrosion potential of Example 1 is significantly higher than that of Comparative Example 1, and its corresponding corrosion current is also lower. This indicates that the tin metal negative electrode in Example 1 is less susceptible to corrosion, and even if corrosion occurs, the rate is significantly slower than that of Comparative Example 1, demonstrating that the tin metal negative electrode in Example 1 has excellent corrosion resistance.

[0048] Figure 2 and Figure 3 The following are scanning electron microscope images of the tin metal anodes in Comparative Example 1 and Example 1 after 100 cycles. It can be observed that a large amount of unevenly distributed "dead tin" is present on the surface of the tin metal anode in Comparative Example 1 after cycling. In contrast, the surface of the tin metal anode in Example 1 remains smooth and dense after cycling, demonstrating that the tin deposition process in Example 1 is more uniform.

[0049] Figure 4 and Figure 5 The figures are the rate cycle curves of the symmetrical batteries prepared in Comparative Example 1 and Example 1 respectively. Figure 4 As shown in the figure, when the tin metal negative electrode is cycled in Comparative Example 1, the polarization of the battery increases rapidly with the increase of current density, and at 10 mA cm -2 When the Figure 6 As can be seen from the figure, the tin metal negative electrode can operate stably at each current density, up to 30 mA cm -2 More importantly, when the current drops back to 1 mA·cm -2 When the tin metal in Example 1 was charged and discharged, the tin ion deposition / dissolution behavior continued normally, while a battery short circuit occurred in Comparative Example 1. These results indicate that the tin metal negative electrode in Example 1 has excellent ion transport capability, ensuring that the tin ion concentration remains uniformly distributed at a high rate, thereby achieving highly stable deposition / stripping behavior.

[0050] Figure 6The asymmetric batteries prepared in Comparative Example 1 and Example 1 were tested at a current density of 10 mA·cm -2 , the deposition surface capacity is 1 mAh·cm -2 Cycle performance diagram when . Figure 6 It can be seen that the tin metal negative electrode in Comparative Example 1 experienced only less than 600 high reversible cycles before the coulombic efficiency dropped rapidly to 60%, indicating that too much "dead tin" was produced during the deposition / stripping process of tin and quickly fell off the substrate, resulting in the inability to maintain a high reversible cycle. In Example 1, the tin metal negative electrode was able to achieve 10,000 high reversible cycles with an average coulombic efficiency of 99.96%. This shows that the tin metal negative electrode in Example 1 has extremely high tin deposition / stripping reversibility and excellent cycle stability.

[0051] Figure 7 The electrochemical performance diagram of the tin-manganese battery prepared in Comparative Example 1 and Example 1 at different current densities is shown. Figure 7 As shown in the figure, as the current density continues to increase, the coulombic efficiency of the tin metal negative electrode in Comparative Example 1 decreases rapidly, which indicates that the reversibility of the tin metal negative electrode at high rates is poor. In Example 1, the tin metal negative electrode can always maintain a high coulombic efficiency, which shows that the problems of "dead tin" and ion transport are significantly alleviated in Example 1, and the tin ion concentration distribution can remain uniform for a long time, thereby effectively suppressing the growth of irregular large tin dendrites.

[0052] Figure 8 and Figure 9 The figures are the capacity-voltage curves of the tin-manganese battery prepared in Comparative Example 1 and Example 1 at different current densities. Figure 8 It can be observed that with the continuous increase of current density, the discharge platform of the tin-manganese battery in comparative example 1 drops rapidly and eventually disappears. This not only means that the ion transport capacity of the tin metal negative electrode in comparative example 1 is poor, but also reflects that many side reactions occur on the positive electrode side, resulting in a rapid decline in surface capacity. In sharp contrast, the discharge platform of the tin-manganese battery in Example 1 is always obvious and stable ( Figure 9 ), which shows that the tin-manganese battery in Example 1 has excellent rate performance and effectively suppresses the side reactions occurring on the positive electrode side.

[0053] Figure 10 The tin-manganese battery prepared in Comparative Example 1 and Example 1 was -2 Long cycle performance diagram. Figure 10 It can be clearly found that the tin-manganese battery in Example 1 has a high -2 It can provide about 0.5 mAh cm at a high current density. -2The reversible surface capacity was 1000,000 cycles, and the high reversible capacity was maintained for nearly 6,000 cycles. However, the tin-manganese battery in Comparative Example 1 not only experienced frequent fluctuations during cycling, but also rapidly failed after less than 2,700 cycles. This indicates that the tin-manganese battery in Example 1 not only has an excellent cycle life, but also has extremely high tin deposition / stripping reversibility.

[0054] Example 2

[0055] This embodiment provides a method for preparing an aqueous electrolyte that can be used for high-rate tin metal anode and tin-manganese battery. The main differences between this method and Example 1 are as follows:

[0056] In step (2), 10.36 g of indium sulfate is added to 200 mL of 0.2 mol / L tin sulfate electrolyte to obtain an aqueous electrolyte that can be used for a high-rate tin metal negative electrode.

[0057] The remaining steps and experimental parameters involved were the same as those in Example 1.

[0058] Example 3

[0059] This embodiment provides a method for preparing an aqueous electrolyte that can be used for high-rate tin metal anode and tin-manganese battery. The main differences between this method and Example 1 are as follows:

[0060] In step (2), 2.59 g of indium sulfate is added to 200 mL of 0.2 mol / L tin sulfate electrolyte to obtain an aqueous electrolyte that can be used for a high-rate tin metal negative electrode.

[0061] The remaining steps and experimental parameters involved were the same as those in Example 1.

[0062] Example 4

[0063] This embodiment provides a method for preparing an aqueous electrolyte that can be used for high-rate tin metal anode and tin-manganese battery. The main differences between this method and Example 1 are as follows:

[0064] In step (2), 3.42 g of aluminum sulfate is added to 200 mL of 0.2 mol / L tin sulfate electrolyte to obtain an aqueous electrolyte that can be used for high-rate tin metal negative electrodes.

[0065] The remaining steps and experimental parameters involved were the same as those in Example 1.

[0066] Example 5

[0067] This embodiment provides a method for preparing an aqueous electrolyte that can be used for high-rate tin metal anode and tin-manganese battery. The main differences between this method and Example 1 are as follows:

[0068] In step (2), 4.28 g of gallium sulfate is added to 200 mL of 0.2 mol / L tin sulfate electrolyte to obtain an aqueous electrolyte that can be used for high-rate tin metal negative electrodes.

[0069] The remaining steps and experimental parameters involved were the same as those in Example 1.

[0070] Example 6

[0071] This embodiment provides a method for preparing an aqueous electrolyte that can be used for high-rate tin metal anode and tin-manganese battery. The main differences between this method and Example 1 are as follows:

[0072] In step (2), 0.4 mL of polyamine is added to 199.6 mL of 0.2 mol / L tin sulfate electrolyte to obtain an aqueous electrolyte that can be used for high-rate tin metal anode.

[0073] The remaining steps and experimental parameters involved were the same as those in Example 1.

[0074] Example 7

[0075] This embodiment provides a method for preparing an aqueous electrolyte that can be used for high-rate tin metal anode and tin-manganese battery. The main differences between this method and Example 1 are as follows:

[0076] In step (2), 0.4 mL of polyamine and 2.59 g of indium sulfate are added to 199.6 mL of 0.2 mol / L tin sulfate electrolyte to obtain an aqueous electrolyte that can be used for a high-rate tin metal negative electrode.

[0077] The remaining steps and experimental parameters involved were the same as those in Example 1.

[0078] Example 8

[0079] This embodiment provides a method for preparing an aqueous electrolyte that can be used for high-rate tin metal anode and tin-manganese battery. The main differences between this method and Example 1 are as follows:

[0080] In step (2), 0.4 mL of polyamine and 3.42 g of aluminum sulfate are added to 199.6 mL of 0.2 mol / L tin sulfate electrolyte to obtain an aqueous electrolyte that can be used for high-rate tin metal negative electrodes.

[0081] The remaining steps and experimental parameters involved were the same as those in Example 1.

[0082] Example 9

[0083] This embodiment provides a method for preparing an aqueous electrolyte that can be used for high-rate tin metal anode and tin-manganese battery. The main differences between this method and Example 1 are as follows:

[0084] In step (2), 0.4 mL of polyamine and 4.28 g of gallium sulfate are added to 199.6 mL of 0.2 mol / L tin sulfate electrolyte to obtain an aqueous electrolyte that can be used for a high-rate tin metal negative electrode.

[0085] The remaining steps and experimental parameters involved were the same as those in Example 1.

[0086] The symmetrical cells prepared in Examples 1-5 and Comparative Example 1 were heated at a current density of 1 mA·cm -2 , the deposition surface capacity is 1 mAh·cm -2 The electrochemical test results are shown in Table 1.

[0087] It can be seen from Table 1 that the cycle life of Examples 1-5 all exceeds that of Comparative Example 1, among which Example 1 has the best electrochemical performance, indicating that the improvement effect of this Example is the most obvious.

[0088] Table 1 Cycle life of symmetrical batteries in Examples 1-5 and Comparative Example 1

[0089] Cycle life (hours) Example 1 7187 Example 2 2500 Example 3 1521 Example 4 1388 Example 5 800 Comparative Example 367

[0090] The asymmetric batteries prepared in Examples 3-9 and Comparative Example 1 were heated at a current density of 5 mA·cm -2 , the deposition surface capacity is 1 mAh·cm -2 The electrochemical test results are shown in Table 2.

[0091] As can be seen from Table 2, the initial coulombic efficiency of Examples 3-9 is superior to that of Comparative Example 1. After adding a trace amount of polyamine, the initial coulombic efficiency is improved, but the polarization voltage also increases slightly, which may reduce the ion transfer rate to some extent. However, adding a high-valent metal salt and polyamine simultaneously can further improve the initial coulombic efficiency and reduce the polarization voltage. This indicates that there is a positive synergistic effect between the high-valent metal salt and the polyamine, which enables good tin ion transfer kinetics while maintaining highly reversible deposition behavior.

[0092] Table 2 First coulombic efficiency and polarization voltage of asymmetric batteries in Examples 3-9 and Comparative Example 1

[0093]

[0094]

[0095] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. It is apparent to those skilled in the art that various changes, modifications, substitutions, and variations of these embodiments may be made without departing from the principles and spirit of the present invention, and the changes still fall within the scope of protection of the present invention.

Claims

1. An aqueous electrolyte for high-rate tin metal negative electrode batteries, characterized in that: The aqueous electrolyte includes an acidic solution, a tin salt, and a high-valent metal salt, wherein the high-valent metal salt includes indium sulfate, gallium sulfate, aluminum sulfate, chromium sulfate, iron sulfate, lanthanum sulfate, cerium sulfate, titanium sulfate, cobalt sulfate, nickel sulfate, lead sulfate, cadmium sulfate, zinc sulfate, copper sulfate, and magnesium sulfate; The aqueous electrolyte further comprises a charged water-soluble polymer, wherein the charged water-soluble polymer comprises polyamine, polyquaternary ammonium salt, polyacrylic acid copolymer, polycarboxylate ether, or ionic polyurethane; The volume of the charged water-soluble polymer accounts for 0.01%-1% of the total electrolyte volume.

2. The aqueous electrolyte for high-rate tin metal negative electrode batteries according to claim 1, characterized in that: The tin salts include tin sulfate, tin chloride, tin bromide, tin iodide, tin fluoride, tin oxalate, tin fluorophosphate, tin pyrophosphate, tin trifluoromethanesulfonate, tin tetrafluoroborate, tin nitrate, and tin acetate.

3. The aqueous electrolyte for high-rate tin metal negative electrode batteries according to claim 1, characterized in that: The acidic solution includes sulfuric acid, hydrochloric acid, nitric acid, bromic acid, iodic acid, hydrofluoric acid, oxalic acid, phosphoric acid, diphosphoric acid, trifluoromethanesulfonic acid, tetrafluoroboric acid, and acetic acid.

4. The aqueous electrolyte for high-rate tin metal negative electrode batteries according to claim 1, characterized in that: The aqueous electrolyte also includes a manganese salt.

5. The aqueous electrolyte for high-rate tin metal negative electrode batteries according to claim 4, characterized in that: The manganese salts include manganese sulfate, manganese chloride, manganese nitrate, manganese bromide, manganese iodide, manganese tin fluoride, manganese oxalate, manganese phosphate, manganese hydrogen phosphate, manganese dihydrogen phosphate, manganese trifluoromethanesulfonate, and manganese acetate.

6. The aqueous electrolyte for high-rate tin metal negative electrode batteries according to claim 1, characterized in that: The concentration of the tin salt is in the range of 0.01mol / L-1mol / L; the acidic solution is a mixture of acid and water, and the concentration range is 0.1mol / L-3mol / L; the concentration range of the high-valent metal salt is 0.01mol / L-1mol / L.

7. Use of the aqueous electrolyte according to any one of claims 1 to 6 in preparing an aqueous battery, characterized in that: The aqueous battery includes a tin symmetric battery or a tin asymmetric battery.

8. The use according to claim 7, characterized in that The tin asymmetric battery includes a tin-manganese battery.

9. The use according to claim 7, characterized in that The tin symmetrical battery or the tin asymmetrical battery is assembled by coupling tin foil and metal foil.

10. The use according to claim 8, characterized in that The tin-manganese battery is assembled by coupling tin foil and a positive electrode current collector.

Images