Water-based aluminum ion battery system capable of realizing stable operation in extremely wide temperature range

Abstract

The invention provides a water-based aluminum ion battery system capable of realizing stable operation in an extremely wide temperature range. The water-based aluminum ion battery system mainly comprises an aluminum ion battery nano-porous negative electrode and a hydrated eutectic electrolyte thereof, wherein the aluminum ion battery nano-porous negative electrode stably operates in a temperature environment of-30 DEG C to 50 DEG C; main components of the nano-porous negative electrode comprise 80-95 wt.% of Al and 5-20 wt.% of Zn, simple etching is carried out in a NH4Cl + HCl mixed solution, the surface active Zn element can be eliminated, meanwhile, the Al crystal face orientation on the surface of the negative electrode is directionally changed, a nano-scale porous net structure is formed on the surface, and the inherent low electrochemical activity of the metal negative electrode Al is effectively improved. Main components of the hydrated eutectic electrolyte comprise 30-80 wt.% of Al (ClO4) 3, 10-40 wt.% of panthenol and 10-60 wt.% of H2O, a eutectic network formed by Al (ClO4) 3 and panthenol is utilized, the freezing point of the electrolyte is greatly reduced, the electrolyte has excellent low-temperature ionic conductivity, the panthenol can effectively inhibit the activity of electrolyte water, and parasitic side reactions in the running process of the aqueous battery are greatly reduced. The system can stably operate in a wide temperature environment of-30 DEG C to 50 DEG C, and has an excellent application prospect.

Description

Technical Field

[0001] This invention relates to the field of aqueous metal-ion batteries, and in particular to an aqueous aluminum-ion battery system that can achieve stable operation over an extremely wide temperature range. Background Technology

[0002] Aluminum-ion batteries have a high theoretical capacity (8046 mAh·cm³). -3 With its abundant resources and other advantages, it is considered a highly promising alternative to lithium-ion batteries (2042 mAh·cm⁻¹). -3 A novel type of metal-ion battery. Compared to traditional ionic and molten salt electrolytes, aqueous aluminum-ion batteries using aqueous solutions of AlCl3, Al2(SO4)3, Al(OTF)3, and Al(ClO4)3 as the electrolyte matrix have higher ionic conductivity, excellent safety, a wider range of applications, and lower cost, making aqueous aluminum-ion batteries the core development direction in aluminum-ion batteries.

[0003] Although aqueous aluminum-ion batteries have many advantages, they are still in the early stages of research and many problems remain to be solved. For example, at both room temperature and high temperature (>40℃), the large number of highly active water molecules inside the aqueous electrolyte makes it difficult for the extremely narrow electrochemical stability window of water molecules (1.23V) to cope with the low reduction potential of Al (-1.66V). vs. This results in parasitic side reactions such as water desorption and hydrogen deposition being far greater than aluminum deposition reactions during battery operation, sometimes even preventing proper aluminum deposition. Simultaneously, the low pH characteristic of aqueous aluminum electrolytes inevitably leads to corrosion of the negative electrode surface, promoting uneven deposition, inducing dendrite formation, and ultimately causing short circuits. At low temperatures (<0℃), conventional aqueous electrolytes have high freezing points, failing to meet the requirements for low-temperature environments, and are prone to freezing, leading to difficulties in ion transport. Furthermore, low temperatures significantly reduce Al... 3+ The deposition / stripping kinetics cause a significant increase in nucleation overpotential and polarization voltage, ultimately leading to battery failure.

[0004] In summary, to ensure the stable operation of aqueous aluminum-ion batteries over an extremely wide temperature range, it is urgent to construct a new aqueous aluminum-ion battery system that can achieve stable cycling under high-temperature to extremely cold environments.

[0005] The references are as follows: [1] Faegh, E.; Ng, B.; Hayman, D.; Mustain, WE Practicalassessment of the performance of aluminum battery technologies. Nature Energy 2020, 6 (1), 21-29. [2] Tu, J.; Song, W.-L.; Lei, H.; Yu, Z.; Chen, L.-L.; et al.Nonaqueous Rechargeable Aluminum Batteries: Progresses, Challenges, andPerspectives. Chemical Reviews 2021, 121 (8), 4903-4961. [3] Geng, X.; Hou, X.; He, X.; Fan, H. J. Challenges and Strategieson Interphasial Regulation for Aqueous Rechargeable Batteries. Advanced Energy Materials 2024, 14 (12), 2304094. [4] Jiang, M.; Fu, C.; Meng, P.; Ren, J.; Wang, J.; et al. Challengesand Strategies of Low‐Cost Aluminum Anodes for High‐Performance Al‐BasedBatteries. Advanced Materials 2021, 34 (2), 2102026. [5] Ma, D.; Yuan, D.; Ponce de León, C.; Jiang, Z.; Xia, X.; et al.Current Progress and Future Perspectives of Electrolytes for RechargeableAluminum‐Ion Batteries. Energy & Environmental Materials 2022, 6 (1), e12301. [6] Qiu, M.; Sun, P.; Han, K.; Pang, Z.; Du, J.; et al. Tailoringwater structure with high-tetrahedral-entropy for antifreezing electrolytes and energy storage at -80 °C. Nature Communications 2023, 14 (1), 601. [7] Luo, ACS Nano 2024, 18 (20), 12981-12993. Summary of the Invention

[0006] The purpose of this invention is to provide an aqueous aluminum-ion battery system that can achieve stable operation over an extremely wide temperature range.

[0007] To achieve the above objectives, the solution of the present invention is: A water-based aluminum-ion battery system capable of stable operation over an extremely wide temperature range is disclosed. The battery system comprises: a hydrated eutectic electrolyte, a porous aluminum anode material, a separator material, and a composite cathode material. The hydrated eutectic electrolyte is composed of aluminum salt crystals, panthenol, and water. The porous aluminum anode material is a metallic aluminum material with a surface nano-network porous structure.

[0008] Preferably, the aluminum salt crystal is composed of one or more of AlCl3∙6H2O, Al(NO3)3∙9H2O, or Al(ClO4)3∙9H2O.

[0009] Preferably, the diaphragm material is glass fiber.

[0010] Preferably, the composite cathode material is formed by composite of polyaniline loaded on a carbon fiber cloth current collector.

[0011] The preparation method of the aforementioned aqueous aluminum-ion battery system with a surface nano-network porous structure that can achieve stable operation over an extremely wide temperature range includes the following specific steps: An aluminum alloy foil is placed in an electrolyte and electrochemically etched to form a network porous structure with a pore size of 100-500 nm on the surface of the aluminum foil; the aluminum alloy foil is a commercially available aluminum alloy foil composed of 80-95 wt.% Al and 5-20 wt.% Zn; the electrolyte is a hydrochloric acid solution containing ammonium chloride.

[0012] Preferably, the electrochemical etching is plasma-assisted electrochemical etching.

[0013] The preparation method of the hydrated eutectic electrolyte in the aforementioned aqueous aluminum-ion battery system that can achieve stable operation over an extremely wide temperature range is as follows: aluminum salt crystals and panthenol are mixed and heated and stirred until a thick eutectic electrolyte is formed, and then deionized water is added for ultrasonic treatment.

[0014] Preferably, the mass fraction of aluminum salt crystals is 35-60 wt.%, the mass fraction of panthenol is 25-40 wt.%, and the mass fraction of water is 10-40 wt.%.

[0015] Preferably, the heating and stirring temperature is 40-80℃.

[0016] A wide-temperature-range aqueous aluminum-ion battery, comprising the aforementioned system, wherein the aluminum-ion battery can stably cycle for more than 500 hours at 50°C and can stably cycle for more than 300 hours at -30°C.

[0017] The principle of this invention is as follows: The aqueous aluminum-ion battery system provided by this invention, capable of stable operation over an extremely wide temperature range, successfully addresses the challenges faced by current aqueous aluminum-ion batteries under various temperature conditions by employing a surface nano-network porous aluminum metal anode and a hydrated eutectic electrolyte. Specifically, under normal / high temperature conditions, the eutectic system formed by panthenol and aluminum perchlorate nonahydrate in the hydrated eutectic electrolyte disrupts the original hydrogen bond network, significantly inhibiting water decomposition activity, thereby effectively extending the overall electrochemical stability window of the electrolyte and facilitating stable aluminum deposition / stripping. The surface nano-network porous aluminum metal anode is prepared by etching commercially available zinc-aluminum alloy foil. During the etching process, not only is the active Zn metal on the surface of the zinc-aluminum alloy foil stripped, but also the H-philic... + The Al(220) crystal plane selectively dissolves, exposing Al-loving surfaces. 3+ The Al(311) crystal plane, in combination with the hydrated eutectic electrolyte, can effectively suppress the spontaneous corrosion of the negative electrode Al during battery operation, thereby improving the service life of the aluminum metal negative electrode.

[0018] The wide-temperature-range aqueous aluminum-ion battery provided by this invention can operate stably under extremely cold conditions. This is because the panthenol-Al(ClO4)3-H2O hydrated eutectic electrolyte system used still maintains good ionic conductivity under extremely cold conditions. It should be noted that adding water to the hydrated eutectic electrolyte system effectively improves the fluidity of the eutectic electrolyte and ensures stable physical properties under normal high-temperature and low-temperature conditions. This provides the core foundation for the improved hydrated eutectic electrolyte to operate in extremely cold environments. Furthermore, on the negative electrode side of the aluminum-ion battery, the nano-network porous structure provides a larger conductive interface for metal ions, effectively improving the kinetics of the ion transport interface; while the Zn element inside the negative electrode (-0.76V)... vs. The hydrated eutectic electrolyte (SHE) provides a more positive potential for Al ion deposition, thereby inducing underpotential deposition of Al ions. Therefore, the hydrated eutectic electrolyte and the porous aluminum metal anode with a nano-network structure on the surface mutually promote the stable operation of this aqueous aluminum-ion battery in extremely cold environments.

[0019] Compared to existing methods, the gains of this invention are as follows: 1. The aqueous aluminum-ion battery system provided by this invention can successfully achieve stable cyclic operation within an extremely wide temperature range of -30℃ to 50℃.

[0020] 2. The aqueous aluminum-ion battery system that operates stably over an extremely wide temperature range provided by this invention has advantages such as simple preparation process, low material cost, and good industrial development prospects.

[0021] 3. The wide-temperature-range aqueous aluminum-ion battery provided by this invention has undergone electrochemical performance testing. The results show that the symmetrical battery system of this aqueous aluminum-ion battery can stably cycle for more than 500 hours at 50℃ and for more than 300 hours at -30℃. For the full cell using polyaniline as the positive electrode, it can achieve stable cycling for 300 cycles at 50℃, maintaining a capacity of 152 mAh g⁻¹. -1 The coulombic efficiency remains above 98%; it can be stably cycled 150 times at -30℃, maintaining a capacity of 105mAh g. -1 Coulomb efficiency remains above 99.5%. Attached Figure Description

[0022] Figure 1 XRD comparison diagram of the aluminum metal anode provided by the present invention.

[0023] Figure 2 The images show a comparison of SEM images of the metal anode prepared in Example 1 before and after etching.

[0024] Figure 3 The image shows the XPS spectrum of the metal anode prepared in Example 1.

[0025] Figure 4 The Raman spectra of different electrolytes provided by this invention are shown.

[0026] Figure 5 Infrared spectra of different electrolytes provided by this invention.

[0027] Figure 6 Infrared spectra of different electrolytes provided by this invention.

[0028] Figure 7 This is a comparison diagram of the electrochemical windows of different electrolytes provided by the present invention.

[0029] Figure 8 Different electrolytes provided by the present invention 27 Al NMR spectrum comparison diagram.

[0030] Figure 9 This is a comparison chart of DSC curves for different electrolytes provided by the present invention.

[0031] Figure 10 This is a comparison chart of the ionic conductivity of different electrolytes provided by the present invention at different temperatures.

[0032] Figure 11 The image shows the SEM image of the metal anode prepared in Example 2.

[0033] Figure 12 The image shows a SEM image of the metal anode prepared in Example 3.

[0034] Figure 13 This is a SEM image of the metal anode prepared in Example 4.

[0035] Figure 14 This is a SEM image of the metal anode prepared in Example 5.

[0036] Figure 15 The image shows a SEM image of the metal anode prepared in Example 6.

[0037] Figure 16 The image shows a SEM image of the metal anode prepared in Example 7.

[0038] Figure 17 A photograph of the non-flowing solid mixture formed during the preparation of the electrolyte in Example 9. Detailed Implementation

[0039] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should also be understood that the following embodiments are only for further illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Specific mass, reaction time, temperature, process parameters, etc., in the examples are merely examples within a suitable range. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention.

[0040] Unless otherwise specified, all reagents used are commercially available and were not further purified before use.

[0041] Example 1 The preparation method of the surface nano-network porous aluminum metal anode is as follows: A commercial aluminum alloy foil containing 85 wt.% Al and 15 wt.% Zn is immersed in a 0.1 M HCl solution containing 5 M ammonium chloride, and plasma-assisted electrochemical etching is performed at room temperature. The specific steps are as follows: first, the electrode is treated with argon plasma at a power of 300 W for 25 min; then, a stepped electrochemical etching process is performed, including: a first stage applying a 6 V voltage for 3 min to form initial porous channels; a second stage applying a 12 V voltage pulse at a frequency of 5 Hz for 8 min; and a third stage applying a 15 V voltage gradient decrease, reducing the voltage by 0.5 V every 30 seconds until the voltage reaches zero. The etched aluminum metal anode (NP-Al) is then ultrasonically cleaned in anhydrous ethanol for 5 min to remove residual hydrochloric acid and ammonium chloride impurities. The etched aluminum alloy foil is characterized by XRD, and the results are as follows. Figure 1 As shown: Figure 1 Crystal plane analysis of different aluminum anodes is presented, with the commercially available pure Al sheet (Com-Al) used in Comparative Example 1 and the commercially available Al sheet used in Comparative Example 2 being compared. 85 Zn 15 The aluminum alloy foil is predominantly composed of (220) crystal planes, while the NP-Al aluminum metal anode after etching modification is predominantly composed of (311) crystal planes. The Al (311) crystal planes exhibit stronger acid resistance and aluminophilicity, which provides a basis for the stability of the anode-electrolyte interface. SEM characterization of the aluminum alloy foils before and after etching was performed, and the results are as follows: Figure 2 As shown: Figure 2 a shows the SEM morphology of the aluminum sheet before modification; Figure 2 b shows the surface morphology of NP-Al prepared by etching aluminum foil. NP-Al exhibits a more uniform nanoporous network structure, which provides a larger contact interface for the electrolyte, thereby effectively improving the kinetics of interfacial ion mass transfer. The surface and interior of the etched aluminum alloy foil NP-Al were characterized by 100 nm XPS, and the results are as follows. Figure 3 As shown: Figure 3XPS spectra of the surface and interior of NP-Al at 100 nm were displayed. The change in the atomic ratio of Al to Zn further confirmed the preparation mechanism. Most of the active Zn metal was exfoliated on the surface, forming a network porous morphology. The active metal in the deep nanolayer not only improves the problem of easy oxidation under atmospheric conditions, but also induces Al in the battery during operation. 3+ The underpotential deposition effectively improves the electrochemical activity of metallic Al.

[0042] Preparation method of hydrated eutectic electrolyte: Weigh and mix 4g Al(ClO4)3·9H2O and 3.5g panthenol in a beaker to form a 1M Al(ClO4)3 solution. Heat and stir the resulting solution at 60℃ for 1h to form a viscous eutectic electrolyte (Al(ClO4)3-PB). Then add 2.5g deionized water and sonicate the mixture for 15min at a frequency of 30kHz and a temperature of 50℃ to prepare the hydrated eutectic electrolyte (Al(ClO4)3-PB-H2O). Raman spectroscopy characterization of the prepared hydrated eutectic electrolyte is shown in the figure below. Figure 4 As shown: Figure 4 The OH stretching behavior of different electrolytes was demonstrated. It can be observed that the hydrated eutectic electrolyte formed by adding panthenol (PB) showed a significant suppression of the OH bond strength compared to the original 1M Al(ClO4)3 solution. The prepared hydrated eutectic electrolyte was characterized by infrared spectroscopy, and the results are as follows: Figure 5 and Figure 6 As shown: Figure 5 The OH stretching behavior of different electrolytes was also shown, which is consistent with the conclusions obtained from Raman spectroscopy. Figure 6 It demonstrates the relationship between the C=O bond and ClO4. - The bending and shifting behavior in response to changes in the electrolyte confirms its participation in the solvation structure of Al. 3+ Coordination. Electrochemical window testing was performed on the prepared hydrated eutectic electrolyte, and the results are as follows: Figure 7 As shown, the electrochemical stability window of the Al(ClO4)3-PB-H2O system is significantly extended compared to 1M Al(ClO4)3. Nuclear magnetic resonance (NMR) spectroscopy analysis of the different prepared electrolytes yielded the following results: Figure 8 As shown: Figure 8 This demonstrates the presence of [Al] in the Al(ClO4)3-PB system and the Al(ClO4)3-PB-H2O system. 3+ ...H2O] and [Al 3+ ...PB] two coordination environments, and relative to the original electrolyte of 1M Al(ClO4)3, [Al 3+ The H2O signal weakened significantly, and combined with the aforementioned infrared spectrum, this indicated that PB's addition affected Al.3+ This provides valid evidence of solvation-induced structural remodeling, fundamentally reducing the possibility of coordinated H₂O decomposition at the negative electrode interface. Differential scanning calorimetry (DSC) was performed on the prepared hydrated eutectic electrolyte, and the results are as follows: Figure 9 As shown: Figure 9 The DSC curves confirmed the formation of a unique eutectic network, effectively lowering the melting point of the electrolyte and enabling ultra-low temperature battery cycling. The viscosity and ionic conductivity of the prepared electrolyte were tested at different temperatures, and the results are as follows: Figure 10 As shown: Figure 10 The viscosity and ionic conductivity of different electrolytes at different temperatures were demonstrated. On the one hand, it was confirmed that Al(ClO4)3-PB-H2O has excellent ion transport capabilities under extremely low temperature conditions. On the other hand, it was confirmed that the addition of H2O effectively improved the disadvantage of low ionic conductivity caused by excessive viscosity of hydrated eutectic electrolytes.

[0043] Assembly of symmetrical cells: Using a 2032 cell casing, a glass fiber (GF / D) separator, aluminum metal anodes prepared above on both the positive and negative sides, and the prepared hydrated eutectic electrolyte, a button cell is assembled.

[0044] Assembly of the full cell: A 2032 battery case was used, a glass fiber (GF / D) separator was used, an aluminum metal negative electrode prepared above was used, a conventional polyaniline was used as the positive electrode and loaded onto a carbon fiber cloth current collector (active loading 1~2 mg cm-2), and the prepared hydrated eutectic electrolyte was used. The whole cell was assembled into a button cell.

[0045] Electrochemical cycling tests were conducted on the above-mentioned batteries using the Xinwei Battery Testing System. The voltage range was set to 1.5V~0.4V, and the current range was set to 0.1A~1A g⁻¹. The batteries were placed in a constant temperature chamber with the temperature set to -30℃~50℃ to simulate high temperature / room temperature / extreme low temperature environmental conditions. The test results are shown in Tables 1 and 2.

[0046] Example 2 The preparation method of the surface nano-mesh porous aluminum metal anode is the same as in Example 1, except that the commercial aluminum alloy foil with 85 wt.% Al and 15 wt.% Zn is replaced with a commercial aluminum alloy foil with 80 wt.% Al and 20 wt.% Zn. All other steps are the same as in Example 1. The prepared metal anode was characterized by SEM, and the results are as follows. Figure 11 As shown; from Figure 11 As can be seen, due to the high Zn content in the aluminum alloy foil used, the etching ratio is high, and the surface of the prepared metal anode exhibits uneven porosity. This indicates that the etching effect is poor, so battery assembly and electrochemical testing were not carried out.

[0047] Example 3 The preparation method of the surface nano-network porous aluminum metal anode is the same as in Example 1, except that the commercial aluminum alloy foil with 85 wt.% Al and 15 wt.% Zn is replaced with a commercial aluminum alloy foil with 95 wt.% Al and 5 wt.% Zn. All other steps are the same as in Example 1. The prepared metal anode was characterized by SEM, and the results are as follows. Figure 12 As shown; from Figure 12 As can be seen, due to the low Zn content in the aluminum alloy foil used, the etching reaction is weak, and the surface of the prepared metal anode exhibits an overall uneven grooved structure, resulting in limited modification of the active surface. Referring to Example 1, the prepared aluminum metal was used as the anode for battery assembly and subsequent electrochemical testing; the test results are shown in Tables 1 and 2.

[0048] Example 4 The preparation method of the aluminum metal anode with a surface nano-network porous structure is the same as in Example 1, except that the plasma-assisted electrochemical etching was replaced by direct immersion etching in a 0.1M HCl solution of 5M ammonium chloride for 5 hours. All other steps are the same as in Example 1. The prepared metal anode was characterized by SEM, and the results are as follows: Figure 13 As shown; from Figure 13 As can be seen from the results, the immersion etching efficiency is too low to achieve selective etching, and it is difficult to form uniform pores on the surface of the prepared metal anode. This indicates that the etching effect is not good, so battery assembly and electrochemical testing were not carried out.

[0049] Example 5 The preparation method of the aluminum metal anode with a surface nano-mesh porous structure is the same as in Example 1, except that the stepped electrochemical etching is replaced with ordinary electrochemical etching. Specifically, the etching is performed continuously at 10V for 20 minutes, while the remaining steps are the same as in Example 1. The prepared metal anode was characterized by SEM, and the results are as follows: Figure 14 As shown; from Figure 14 As can be seen, under these conditions, ordinary electrochemical etching is inefficient and it is difficult to achieve selective dissolution of Al crystal planes. Only local etching can occur, resulting in the formation of multiple local macropores on the metal surface instead of a uniform nano-network pore structure. This indicates that the overall etching effect is poor, so battery assembly and electrochemical testing were not carried out.

[0050] Example 6 The preparation method of the aluminum metal anode with a surface nano-mesh porous structure is the same as in Example 1, except that argon plasma treatment is not performed; all other steps are the same as in Example 1. The prepared metal anode was characterized by SEM, and the results are as follows: Figure 15 As shown; from Figure 15As can be seen, the etching efficiency is relatively low without argon plasma treatment, resulting in only localized etching of the aluminum alloy foil. A large area of ​​the aluminum alloy foil surface remains unreacted, indicating poor etching performance. Therefore, battery assembly and electrochemical testing were not carried out.

[0051] Example 7 The preparation method of the aluminum metal anode with a surface nano-network porous structure is the same as in Example 1, except that the concentration of ammonium chloride is changed to 7M. ​​The prepared metal anode was characterized by SEM, and the results are as follows: Figure 16 As shown; from Figure 16 As can be seen, the excessive concentration of ammonium chloride led to localized over-etching, which destroyed the original nano-network porous structure. This indicates that the etching effect was poor, so battery assembly and electrochemical testing were not carried out.

[0052] Example 8 The preparation method of the hydrated eutectic electrolyte is the same as in Example 1, except that the amount of Al(ClO4)3·9H2O is changed to 3g, the amount of panthenol is changed to 3g, and the amount of deionized water is changed to 4g. The remaining steps are the same as in Example 1. Referring to Example 1, the prepared hydrated eutectic electrolyte was used for battery assembly and electrochemical testing. The test results are shown in Tables 1 and 2.

[0053] Example 9 The preparation method of the hydrated eutectic electrolyte is the same as in Example 1, except that the amount of Al(ClO4)3·9H2O is changed to 8g, the amount of panthenol is changed to 1g, and the amount of deionized water is changed to 1g. All other steps are the same as in Example 1. The results show that Al(ClO4)3·9H2O and panthenol did not form an effective eutectic liquid, exhibiting the following characteristics: Figure 17 The mixture is a non-flowing solid mixture; therefore, battery assembly and electrochemical testing are not possible.

[0054] Example 10 The preparation method of the hydrated eutectic electrolyte is the same as in Example 1, except that the amount of Al(ClO4)3·9H2O is changed to 4g, the amount of panthenol is changed to 4g, and the amount of deionized water is changed to 2g. The remaining steps are the same as in Example 1. Referring to Example 1, the prepared hydrated eutectic electrolyte was used for battery assembly and electrochemical testing. The test results are shown in Tables 1 and 2.

[0055] Table 1 Cycling performance of symmetric cells in different embodiments / control examples at different temperatures

[0056] Table 2 Cycle performance of full cells in different implementations / control examples at different temperatures

[0057] Example 11 The preparation method of the hydrated eutectic electrolyte was the same as in Example 1, except that the amount of Al(ClO4)3·9H2O was changed to 3.5g, the amount of panthenol to 0.5g, and the amount of deionized water to 6g. All other steps were the same as in Example 1. The results showed that Al(ClO4)3·9H2O and panthenol did not form an effective eutectic liquid, exhibiting a non-flowing solid mixture state as shown in Example 9; therefore, battery assembly and electrochemical testing were not possible.

[0058] Comparative Example 1 The assembly of the symmetrical cell and the full cell are described in Example 1, except that commercially available pure Al sheets (Com-Al) are used directly as the negative electrode for cell assembly and subsequent electrochemical testing; the test results are shown in Tables 1 and 2.

[0059] Comparative Example 2 The assembly of the symmetrical cell and the full cell is shown in Example 1, except that commercial Al is used. 85 Zn 15 The plate was used directly as the negative electrode, and subsequent electrochemical tests were performed; the test results are shown in Tables 1 and 2.

[0060] Comparative Example 3 The assembly of the symmetrical cell and the full cell were carried out in accordance with Example 1, except that the hydrated eutectic electrolyte was replaced with a 1M Al(ClO4)3 solution as the electrolyte for cell assembly and subsequent electrochemical testing; the test results are shown in Tables 1 and 2.

[0061] Comparative Example 4 The preparation of the eutectic electrolyte was carried out in accordance with Example 1, except that the amount of deionized water was changed to 0g. In accordance with Example 1, the prepared hydrated eutectic electrolyte was used for battery assembly and electrochemical testing. The test results are shown in Tables 1 and 2.

[0062] The results in Tables 1 and 2 show that the electrode provided in Example 1 exhibits the best cycle stability and discharge capacity throughout the entire experimental temperature range. Combined with the experimental results of the comparative examples, the following conclusions can be drawn: In Comparative Example 1, the negative electrode directly uses pure metallic Al sheets, whose inherent passivation film results in extremely low electrochemical activity, making it difficult to support the required mass transfer kinetics under extremely cold conditions; in Comparative Example 2, commercially available aluminum alloy Al is directly used... 85 Zn 15The active Zn metal on its surface induces hydrogen evolution side reactions with the electrolyte under high temperature conditions, accelerating battery degradation. In Comparative Example 3, no panthenol was added to the electrolyte, and a conventional aqueous electrolyte was used, which made it impossible to support the normal operation of the battery. The possibility of parasitic side reactions was much greater than that of Al deposition / stripping. In Comparative Example 4, no water was added to the electrolyte. The eutectic electrolyte formed by panthenol and Al(ClO4)3 had a high viscosity at room temperature, which resulted in excessively slow ion transport and low battery efficiency.

[0063] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. An aqueous aluminum-ion battery system capable of stable operation over an extremely wide temperature range, characterized in that, The battery system includes: a hydrated eutectic electrolyte, a porous aluminum anode material, a separator material, and a composite cathode material; wherein the hydrated eutectic electrolyte is composed of aluminum salt crystals, panthenol, and water; and the porous aluminum anode material is a metallic aluminum material with a surface nano-network porous structure.

2. The aqueous aluminum-ion battery system capable of stable operation over an extremely wide temperature range according to claim 1, characterized in that, The aluminum salt crystal is composed of one or more of AlCl3∙6H2O, Al(NO3)3∙9H2O, or Al(ClO4)3∙9H2O.

3. The aqueous aluminum-ion battery system capable of stable operation over an extremely wide temperature range according to claim 1, characterized in that, The diaphragm material is glass fiber.

4. The aqueous aluminum-ion battery system capable of stable operation over an extremely wide temperature range according to claim 1, characterized in that, The composite cathode material is formed by loading polyaniline onto a carbon fiber cloth current collector.

5. The method for preparing a surface nano-network porous structure metallic aluminum material in an aqueous aluminum-ion battery system capable of stable operation over an extremely wide temperature range, as described in claim 1, is characterized in that... The specific steps are as follows: The aluminum alloy foil is placed in the electrolyte for electrochemical etching to form a mesh-like porous structure with a pore size of 100-500 nm on the surface of the aluminum foil; the aluminum alloy foil is a commercially available aluminum alloy foil composed of 80-95 wt.% Al and 5-20 wt.% Zn; the electrolyte is a hydrochloric acid solution containing ammonium chloride.

6. The method for preparing the metallic aluminum material with a surface nano-network porous structure according to claim 5, characterized in that: The electrochemical etching is plasma-assisted electrochemical etching.

7. The method for preparing the hydrated eutectic electrolyte in the aqueous aluminum-ion battery system capable of stable operation over an extremely wide temperature range according to claim 1, characterized in that, The specific steps are as follows: Mix aluminum salt crystals and panthenol, heat and stir until a thick eutectic electrolyte is formed, then add deionized water and sonicate.

8. The method for preparing the hydrated eutectic electrolyte according to claim 7, characterized in that: The mass fraction of aluminum salt crystals is 35-60 wt.%, the mass fraction of panthenol is 25-40 wt.%, and the mass fraction of water is 10-40 wt.

9. The method for preparing the hydrated eutectic electrolyte according to claim 7, characterized in that: The heating and stirring temperature is 40-80℃.

10. A wide-temperature-range aqueous aluminum-ion battery, characterized in that, The aluminum-ion battery comprises the system described in any one of claims 1-9, and the aluminum-ion battery can be stably cycled for more than 500 hours at 50°C and for more than 300 hours at -30°C.

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