Preparation and application of lithium-carbon dioxide battery wide-temperature-range electrolyte with adjustable solvation energy barrier

Abstract

The invention discloses preparation and application of a lithium-carbon dioxide battery wide-temperature-range electrolyte with an adjustable solvation energy barrier, the wide-temperature-range electrolyte comprises a lithium salt, an organic solvent and ionic liquid, and the ionic liquid comprises imidazole ionic liquid and pyridine ionic liquid. According to the electrolyte system, by regulating and controlling competitive coordination of negative ions of the ionic liquid and molecules of the organic solvent to lithium ions, the bonding strength of the lithium ions and the organic solvent is weakened, a desolvation energy barrier is remarkably reduced, the electrolyte shows excellent electrochemical performance in a wide temperature range of-30 DEG C to 90 DEG C, and under the condition that the current density is 10 mu A.cm <-2 >, the performance of the electrolyte is greatly improved. And the charge-discharge polarization voltage difference at the normal temperature is as low as 0.35 V, and the cycle life at the low temperature (-30 DEG C) is stabilized to 790 hours or more under the condition that the current density is 20 [mu] A.cm <-2 >, so that the electrolyte system is obviously superior to a traditional electrolyte system. According to the invention, efficient and stable operation of the electrolyte in a wide temperature range is realized, and a key technical support is provided for application of the lithium-carbon dioxide battery in multiple fields.

Description

Technical Field

[0001] This invention relates to the field of metal-gas battery electrolyte technology, and in particular to the preparation and application of lithium-carbon dioxide battery wide-temperature-range electrolytes with adjustable solvation barriers. Background Technology

[0002] With the rapid development of the global economy and the continuous advancement of science and technology, global warming and the energy crisis are intensifying. Non-proton lithium-carbon dioxide (Li-CO2) batteries have attracted widespread attention due to their ability to store carbon dioxide gas and convert its chemical energy into electrical energy, as well as their extremely high specific energy density (1876 Wh / kg). Furthermore, carbon dioxide, as a reactant gas, gives lithium-carbon dioxide batteries unique advantages and application prospects in specialized fields such as aerospace exploration and deep-sea diving.

[0003] The operating temperature of lithium-carbon dioxide batteries has a significant impact on their electrochemical behavior and performance. However, due to limitations imposed by the electrolyte, batteries cannot operate normally in low or high temperature environments. Traditional research has largely focused on ambient conditions with small temperature differences, neglecting the impact of extreme temperatures on electrolyte and battery performance. Under extreme temperature conditions, the electrolyte faces significant challenges. Specifically, lower temperatures lead to decreased electrolyte conductivity, slower electrode reaction kinetics, and the need for more energy to drive discharge and discharge reactions, thereby increasing overpotential and affecting battery efficiency and lifespan. Conversely, high temperatures may cause electrolyte volatilization, further shortening battery life. Currently, lithium-carbon dioxide battery electrolytes typically consist of lithium salts, organic solvents, and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), which to some extent limits the application of batteries under wide temperature range conditions.

[0004] Ionic liquids (ILs), molten salts composed of asymmetric organic cations and organic or inorganic anions, exhibit unique application potential in lithium-carbon dioxide batteries due to their non-volatile, non-flammable, high thermal stability, and good CO2 adsorption properties. However, the high viscosity and low ionic conductivity of pure ionic liquids severely limit lithium-ion transport efficiency, significantly slowing down battery reaction kinetics, far inferior to traditional organic solvents, thus posing a challenge to their application in lithium-carbon dioxide batteries. Chinese patent CN115692954A discloses a high-temperature resistant lithium-carbon dioxide battery, using a lithium metal sheet as the negative electrode, an imidazole-based ionic liquid to dissolve lithium salt as the electrolyte, a high-temperature resistant porous membrane as the separator, a porous conductive substrate-supported catalyst as the positive electrode, and a metal mesh as the positive electrode current collector. This battery can operate at 1000 mA·g at 80°C. -1 The current density and 1000 mAh·g -1The cutoff capacity is stable for more than 240 charge-discharge cycles, and it exhibits a high discharge plateau of ~2.69V and a low charging voltage of ~4.22V. In addition, high temperature effectively promotes the reduction and precipitation reaction kinetics of carbon dioxide in lithium-carbon dioxide batteries, greatly improving the charge-discharge stability of batteries under high current density, and exhibiting excellent rate and cycle stability in high temperature environments.

[0005] While the ionic liquids introduced in the aforementioned patents possess high thermal stability and low volatility, their high viscosity results in insufficient ionic conductivity, limiting the rapid transport of lithium ions. Furthermore, they are difficult to form dynamically stable solvation structures at extremely low temperatures. The strong binding between solvent molecules and lithium ions causes the solvation structure to freeze at low temperatures, weakening the battery's cycle stability and environmental adaptability.

[0006] Therefore, there is an urgent need for an electrolyte that can be used in a wide temperature range in lithium-carbon dioxide batteries, thereby overcoming the limitations of pure ionic liquids at extreme temperatures. Summary of the Invention

[0007] The purpose of this invention is to provide the preparation and application of a wide-temperature-range electrolyte for lithium-carbon dioxide batteries with adjustable solvation barriers, in order to solve the problem that the above-mentioned pure ionic liquids have limitations when used as electrolytes for lithium-carbon dioxide batteries at extreme temperatures.

[0008] To achieve the above objectives, the first aspect of the present invention provides a wide-temperature-range electrolyte with an adjustable solvation barrier, the wide-temperature-range electrolyte comprising a lithium salt, an organic solvent, and an ionic liquid, wherein the ionic liquid comprises an imidazole ionic liquid and a pyridine ionic liquid.

[0009] Traditional lithium-carbon dioxide battery electrolytes have significant drawbacks in wide-temperature applications. First, at high temperatures (above 90°C), organic solvents readily volatilize, leading to electrolyte component loss and a substantial reduction in battery cycle life. Second, at low temperatures (below -30°C), electrolyte conductivity drops sharply, the lithium-ion desolvation energy barrier rises, resulting in a significant increase in polarization voltage during charge and discharge, and reduced energy efficiency. Furthermore, while existing ionic liquids possess high thermal stability and low volatility, their high viscosity leads to insufficient ionic conductivity, limiting the rapid transport of lithium ions. Finally, traditional electrolytes struggle to form dynamically stable solvation structures at extreme temperatures. The strong binding between solvent molecules and lithium ions causes the solvation structure to freeze at low temperatures and accelerates solvent decomposition at high temperatures, further weakening the battery's cycle stability and environmental adaptability.

[0010] To address the aforementioned problems, this invention develops a wide-temperature-range electrode liquid with an adjustable solvation barrier by optimizing the formulation. A specific combination of ionic liquids (imidazolium-based and pyridine-based ionic liquids) synergistically interacts with an organic solvent to construct a weakly solvated electrolyte system. This electrolyte system regulates the competitive coordination of lithium ions between the anions of the ionic liquid and solvent molecules, weakening the solvation binding strength of lithium ions and significantly reducing the desolvation barrier. At low temperatures, this mechanism promotes rapid lithium ion migration, alleviating the problems of decreased conductivity and increased polarization; at high temperatures, the dynamic coordination network suppresses solvent evaporation, maintaining high ionic conductivity. This allows the final electrolyte system to maintain good environmental adaptability at both high and low temperatures, enabling its use in a wide temperature range.

[0011] Preferably, the lithium salt is at least one of inorganic anionic electrolyte lithium salt or organic anionic electrolyte lithium salt.

[0012] Preferably, the lithium salt is at least one of lithium bis(fluoromethanesulfonyl)imide or lithium bis(trifluoromethanesulfonyl)imide.

[0013] Preferably, the organic solvent is an aprotic polar solvent.

[0014] Preferably, the organic solvent is at least one of tetraethylene glycol dimethyl ether or dimethyl sulfoxide.

[0015] Preferably, the imidazole ionic liquid is at least one of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide or 1-butyl-3-methylimidazolium tetrafluoroborate, and the pyridine ionic liquid is N-butyl-N-methylpyrrolidineonium bis(trifluoromethanesulfonyl)imide.

[0016] Preferred,

[0017] The concentration of lithium salt is 0.5–1.5 mol / L;

[0018] The molar ratio of organic solvent to ionic liquid is 3:7;

[0019] The molar ratio of imidazole ionic liquids to pyridine ionic liquids is (1-3):(1-3).

[0020] A second aspect of the present invention provides a method for preparing a wide-temperature-range electrolyte with an adjustable solvation barrier, comprising the following steps:

[0021] (1) In a glove box filled with an inert atmosphere, imidazole ionic liquid and pyridine ionic liquid are mixed to obtain an ionic liquid;

[0022] (2) Mix the ionic liquid with the organic solvent to obtain a mixture;

[0023] (3) Add lithium salt to the mixture in batches, stir and sonicate until a transparent homogeneous solution is obtained, which is the wide temperature range electrolyte.

[0024] The third aspect of the present invention provides the application of a wide-temperature-range electrolyte with adjustable solvation barrier in lithium-carbon dioxide batteries.

[0025] Preferably, the electrode material in the lithium-carbon dioxide battery is a two-dimensional nanoelectrode material with negatively charged surface functional groups.

[0026] Preferably, the assembly process of a lithium-carbon dioxide battery is as follows:

[0027] The Li-CO2 flexible battery was assembled in a glove box under an Ar atmosphere. The catalyst material was a two-dimensional material (MXene) or a reduced graphene oxide flexible membrane electrode. The negative electrode was a lithium sheet, and the separator was glass fiber. The electrolyte was dropped onto both sides of the separator, with a total electrolyte concentration of 20-60 μL. The resulting belt battery was sealed in a heat-shrinkable insulating sleeve, with several small holes left on the cathode side to facilitate CO2 gas transport. The electrochemical performance of the assembled flexible belt battery was measured in a high-purity CO2 atmosphere, with the test temperature controlled between -30 and 90°C.

[0028] This invention not only improves the electrolyte system but also constructs the entire lithium-carbon dioxide battery by combining it with electrode materials. By using two-dimensional materials to restrict the flow of ionic liquid in the nano-electrode material channels, the electrolyte undergoes directional desolvation during charging and discharging. This not only reduces the viscosity of the ionic liquid and improves its ionic conductivity but also significantly enhances the electrochemical performance of the lithium-carbon dioxide battery under a wide temperature range. This overcomes the limitations of pure ionic liquids at extreme temperatures and promotes their practical application in lithium-carbon dioxide batteries.

[0029] Therefore, the preparation and application of the lithium-carbon dioxide battery wide-temperature-range electrolyte with tunable solvation energy barrier using the above-described structure have the following beneficial effects:

[0030] (1) In the electrolyte system constructed by the present invention, the desolvation process of lithium ions is easier to carry out due to the lower energy barrier during charging and discharging. Especially in low temperature environment, the free lithium ions after desolvation can still migrate efficiently in the electrolyte, avoiding the decrease in conductivity caused by the freezing of the solvation structure.

[0031] (2) Under high temperature conditions, the electrolyte system constructed in this invention forms a stable dynamic coordination network through the synergistic effect of anions and organic solvents. This structure can suppress the free volatilization of solvent molecules while maintaining the high ionic conductivity of the electrolyte.

[0032] (3) The electrolyte of the present invention enables lithium-carbon dioxide batteries to operate efficiently and stably in a wide temperature range of -30°C to 90°C, extending cycle life and reducing polarization voltage, providing a reliable solution for energy storage technology in extreme environments (such as aerospace and deep-sea exploration).

[0033] (4) The lithium-carbon dioxide battery of the present invention utilizes two-dimensional materials with surface functional groups (such as MXene, reduced graphene oxide) as electrode materials. Their negative charge characteristics can regulate the cation migration path, further optimize ion transport efficiency, and enhance the adaptability of the electrolyte under extreme temperatures. Therefore, this technology significantly improves the performance of lithium-carbon dioxide batteries under wide temperature range conditions.

[0034] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0035] Figure 1 This is a scanning electron microscope image of Ti3C2 prepared in this invention;

[0036] Figure 2 The differential scanning calorimeter diagrams for Embodiments 1 and 4 and Comparative Example 2 of the present invention are shown below.

[0037] Figure 3 The images show the Raman spectra of Examples 1, 2, 3, and 4 of this invention, and Comparative Examples 1 and 2.

[0038] Figure 4 The linear sweep voltammetric curves of Examples 1 and 5 and Comparative Examples 1 and 2 of this invention are shown.

[0039] Figure 5 The charge-discharge performance of lithium-carbon dioxide batteries in Examples 1, 2, 3, 4, 5 and Comparative Examples 1, 2, 3 at room temperature is shown.

[0040] Figure 6 The rate performance of the lithium-carbon dioxide battery in Example 1 of this invention at a high temperature of 90°C;

[0041] Figure 7 The charge-discharge performance of lithium-carbon dioxide batteries in Examples 1, 2, 3 and Comparative Example 1 of the present invention at a low temperature of -30°C is shown.

[0042] Figure 8 The cycle performance of lithium-carbon dioxide batteries in Examples 1, 2, and 3 of this invention at room temperature;

[0043] Figure 9 This is the cycle performance of a lithium-carbon dioxide battery at low temperature in Example 1 of the present invention. Detailed Implementation

[0044] The present invention will be further described below. It should be noted that this embodiment is based on the present technical solution and provides detailed implementation methods and specific operation processes, but the present invention is not limited to this embodiment.

[0045] Example 1

[0046] This embodiment provides a wide-temperature-range electrolyte with an adjustable solvation barrier. The wide-temperature-range electrolyte comprises lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), 1.67 mL of dimethyl sulfoxide (DMSO), and an ionic liquid, wherein the ionic liquid comprises 1 mL of 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4) and 1.67 mL of N-butyl-N-methylpyrrolidone onium bis(trifluoromethanesulfonyl)imide (Pyr 14 TFSI), BMIMBF4 and Pyr 14 The molar ratio of TFSI is 1:1, BMIMBF4, Pyr 14 The molar ratio of TFSI to DMSO is 1.5:1.5:7. The concentration of lithium bis(trifluoromethanesulfonyl)imide is 0.5 M.

[0047] Example 2

[0048] The difference between this embodiment and Embodiment 1 is that BMIMBF4 and Pyr 14 The molar ratio of TFSI is different; in this embodiment, BMIMBF4 and Pyr... 14 The molar ratio of TFSI is 1:3, BMIMBF4, Pyr 14 The molar ratio of TFSI to DMSO was 0.75:2.25:7. The specific addition amounts were: 0.2 mL of BMIMBF4 and 0.2 mL of Pyr. 14 TFSI is 1 mL, and DMSO is 0.66 mL.

[0049] Example 3

[0050] The difference between this embodiment and Embodiment 1 is that BMIMBF4 and Pyr 14 The molar ratio of TFSI is different; in this embodiment, BMIMBF4 and Pyr... 14 The molar ratio of TFSI is 3:1, BMIMBF4, Pyr 14 The molar ratio of TFSI to DMSO was 2.25:0.75:7. The specific addition amounts were: 1 mL of BMIMBF4 and 1 mL of Pyr. 14 TFSI was 0.557 mL, and DMSO was 1.112 mL.

[0051] Example 4

[0052] The difference between this embodiment and Embodiment 1 is that the type of ionic liquid is different; in this embodiment, the only ionic liquid is Pyr. 14 TFSI.

[0053] Example 5

[0054] The difference between this embodiment and Embodiment 1 is that the types of ionic liquid and organic solvent are different; in this embodiment, the only ionic liquid is Pyr. 14 TFSI, the organic solvent is tetraethylene glycol dimethyl ether (TEGDME).

[0055] Comparative Example 1

[0056] The difference between this comparative example and Example 1 is that no ionic liquid was added. The electrolyte in this comparative example includes lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and dimethyl sulfoxide (DMSO), and the concentration of lithium bis(trifluoromethanesulfonyl)imide is 0.5M.

[0057] Comparative Example 2

[0058] The difference between this comparative example and Example 4 is that the type of ionic liquid is different. The ionic liquid in this comparative example is 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4).

[0059] Comparative Example 3

[0060] The difference between this comparative example and Example 4 is that the type of ionic liquid is different. The ionic liquid in this comparative example is 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMIMTFSI).

[0061] Example 6

[0062] This embodiment provides a method for preparing the electrolytes of Examples 1-5 and Comparative Examples 1-3, including the following steps:

[0063] Step 1): Environmental control and raw material preparation

[0064] Operate in an inert atmosphere (such as argon) glove box, and strictly control the ambient water content to <1ppm and oxygen content to <0.1ppm to avoid oxidation or hydrolysis of electrolyte components.

[0065] Step 2): Mix the ionic liquid with the organic solvent to obtain a mixture.

[0066] Step 3): Addition and dissolution of lithium salt

[0067] Lithium salt was added to the mixture in batches, and the final lithium salt concentration was controlled to be 0.5 mol / L to avoid precipitation caused by excessive local concentration. Then, the mixture was mechanically stirred at 400 rpm for 4 hours under an inert atmosphere to ensure that the lithium salt was fully dissolved and formed a homogeneous system with the solvent and ionic liquid.

[0068] Step 4): Ultrasonic treatment and homogenization

[0069] The mixture is ultrasonically treated for 1 hour to further disperse undissolved particles and eliminate bubbles, forming a transparent and homogeneous electrolyte.

[0070] The electrolyte prepared by the method described in this embodiment is applied to lithium-carbon dioxide batteries.

[0071] Test case

[0072] (1) The electrolytes and electrode materials prepared in the examples and comparative examples were characterized. The characterization results are shown in the appendix. Figures 1-3 .

[0073] Figure 1 SEM images of Ti3C2 electrode material used for assembling lithium-carbon dioxide batteries, from Figure 1 As can be seen, the cross-section of the electrode material exhibits an accordion-like morphology, with a uniform and orderly layered structure that facilitates ion transport and confines the electrolyte.

[0074] The preparation method of Ti3C2 electrode material is as follows:

[0075] S1: Place 10 ml of 12M HCl in a polytetrafluoroethylene liner, dissolve 0.8 g of LiF in the HCl, and then heat and stir in a water bath at 45 °C for 15 min to prepare a selective etchant for the Al layer.

[0076] S2: Take 0.5g of Ti3AlC2 (purchased from Xinxi Technology) and slowly add it to the etching agent. Then, heat and stir in a water bath at 45°C for 24 hours to perform etching.

[0077] S3: Transfer the mixture prepared in S2 to a 50mL centrifuge tube, wash with 1M HCl 2-3 times, then wash with water 3 times until the supernatant reaches neutrality, the precipitate begins to swell, and the supernatant turns blackish-green. Add 30mL of ultrapure water again, shake well and centrifuge 3 times without pouring out the supernatant.

[0078] S4: After shaking the mixture, place it in an ice-water bath and sonicate for 1 hour. Centrifuge again and take the supernatant to obtain a monolayer or few-layer Ti3C2 dispersion.

[0079] S5: Take 10 mL of Ti3C2 dispersion (concentration of 10 mg / mL), weigh 600 mg of MgO and add it to the Ti3C2 dispersion, then stir at room temperature for 24 h.

[0080] S6: Subsequently, the Ti3C2 dispersion was washed three times with 3M glacial acetic acid, washed three times with water, and then 30ml of ultrapure water was added. The mixture was shaken and sonicated for 20min to obtain the expanded Ti3C2 dispersion.

[0081] S7: The MgO-expanded Ti3C2 dispersion was filtered into a film using a vacuum filter and dried under vacuum at 60°C for 15 hours to obtain Ti3C2 electrode material.

[0082] Figure 2 The following are differential scanning calorimeter (DSC) plots of the electrolytes from Examples 1, 4, and Comparative Example 2. Figure 2 As can be seen, the three glass transition onset temperatures were -85.46℃ (Example 1), -84.00℃ (Example 4), and -81.84℃ (Comparative Example 2), respectively. This indicates that the electrolyte formulation with different components or proportions has a significant impact on the glass transition temperature (T0). g The T values ​​in Examples 1 and 4 have a significant impact. g Both were lower than Comparative Example 2, indicating that the electrolytes of Examples 1 and 4 had better low-temperature fluidity, which may be due to the ionic liquid (BMIMBF4 / Pyr). 14 The synergistic effect of TFSI and DMSO reduces the rigidity of the system. Overall, the electrolyte of Example 1 exhibits the best low-temperature performance potential and is suitable for wide-temperature-range energy storage applications.

[0083] Figure 3 The images show the Raman spectra of the electrolytes in Examples 1, 2, 3, and 4, and Comparative Examples 1 and 2. Figure 3 As can be seen, the introduction of ionic liquids (ILs) significantly modulates the solvation structure of DMSO-based electrolytes. In the DMSO-S=O region (1020 / 1040 cm⁻¹), [the solvation structure is significantly modulated]. -1 The addition of IL leads to Li + Coordination with DMSO (1040cm) -1 The peak weakened and split off into free DMSO (1020 cm⁻¹). -1 The peak confirms Li + - The coordination degree of DMSO decreases, and a large amount of DMSO is squeezed out of Li + First solvated sheath layer. Simultaneously, BF4 - Area (620cm) -1 The weakening or disappearance of the signal indicates free BF4 - Li participating in competitive coordination + TFSI - Fingerprint area (710 / 740 / 765cm) -1 The results showed that while increased total ion concentration increased aggregation (AGG, 765 cm⁻¹), it also increased aggregation (AGG, 765 cm⁻¹). -1 ), but Li +Preferentially with IL anions (TFSI) - Or BF4 - This forms coordination pairs rather than large-scale AGG. Furthermore, in TFSI... - ~670cm -1 At the peak (usually attributed to SNS bending vibration), a significant blue shift was observed after adding IL, which directly indicates that Li + -TFSI - Enhanced coordination interactions.

[0084] In summary, IL anions (TFSI) - BF4 - Li competes with DMSO for coordination + This effectively weakened Li + - DMSO-specific strong binding promotes DMSO dissociation, thereby significantly reducing the lithium-ion desolvation energy barrier ΔE S This dynamic competitive coordination mechanism not only weakens DMSO-Li + The binding energy enhances the low-temperature ion migration efficiency and also suppresses the decomposition of DMSO at high temperatures by stabilizing the solvation structure, providing a new strategy for designing high-performance wide-temperature-range electrolytes.

[0085] (2) The electrolytes prepared in the examples and comparative examples were assembled into lithium-carbon dioxide batteries, and the battery performance was tested. The test results are attached. Figures 4-9 .

[0086] The battery assembly process is as follows:

[0087] The Li-CO2 flexible battery was assembled in a glove box under an Ar atmosphere, and the electrode material was a two-dimensional material (Mxene). Figure 1 The electrode material is Ti3C2, the negative electrode is a lithium sheet, and the separator is glass fiber. Electrolytes from the examples or comparative examples are dropped onto both sides of the separator, with a total electrolyte concentration of 40 μL. The resulting belt battery is sealed in a heat-shrinkable insulating sleeve, with several small holes left on the cathode side to facilitate CO2 gas transport. The electrochemical performance of the assembled flexible belt battery is measured in a high-purity CO2 atmosphere, with the test temperature controlled between -30 and 90°C.

[0088] Figure 4 The linear sweep voltammetry curves for Examples 1 and 5 and Comparative Examples 1 and 2 are shown below. Figure 4The results show the electrochemical behavior of different electrolyte samples under a high temperature of 60℃. Example 1 shows a later increase in current, indicating that its electrolyte has good electrochemical stability. In contrast, Comparative Examples 1 and 2 show more significant increases in current at lower potentials, indicating lower stability. In particular, Comparative Example 2 shows the most dramatic increase in current, which may mean that it has high activity but poor stability in the electrochemical reaction.

[0089] Figure 5 To demonstrate the charge-discharge performance of the lithium-carbon dioxide batteries of Examples 1, 2, 3, 4, 5 and Comparative Examples 1, 2, 3 at room temperature, at 10 μA cm⁻¹... -2 During the first charge-discharge cycle at the specified current density, the electrolyte with added ionic liquid exhibited a lower polarization voltage. Example 1 demonstrated the best performance, with a voltage difference of only 0.35V, indicating minimal polarization during charge-discharge, potentially leading to higher energy efficiency and longer cycle life.

[0090] Figure 6 To illustrate the rate performance of the lithium-carbon dioxide battery in Example 1 at a high temperature of 90°C, from... Figure 6 As can be seen, under high temperature conditions of 90℃, the material of Example 1 reacts with different current densities (10 to 200 μA cm⁻¹). -2 Charge-discharge performance at low current densities (e.g., 10 μA cm⁻¹). -2 Under these conditions, Example 1 exhibits a relatively stable voltage plateau and a lower voltage difference of only 0.11V. This indicates that the configured wide-temperature-range electrolyte has good thermal stability and is suitable for applications under high-temperature conditions.

[0091] Figure 7 To illustrate the charge-discharge performance of lithium-carbon dioxide batteries in Examples 1, 2, 3, and Comparative Example 1 at a low temperature of -30°C, from... Figure 7 It can be seen from this that at a low temperature of -30℃, with a current of 10μA cm⁻¹ -2 The first charge-discharge cycle was performed at a current density of [specific value missing]. Example 1 exhibited the best performance compared to the other examples, with a voltage difference of only 0.9V, indicating minimal polarization during charge and discharge. In contrast, Comparative Example 1, without the addition of ionic liquid, showed rapid polarization and a rapid voltage rise during charging, indicating very poor electrochemical performance at low temperatures. The electrolyte with added ionic liquid exhibited better performance at low temperatures because the ionic liquid has a lower freezing point and higher ionic conductivity, allowing the battery to maintain good ion migration and charge transfer even at low temperatures.

[0092] Figure 8To illustrate the cycle performance of lithium-carbon dioxide batteries in Examples 1, 2, and 3 of this invention at room temperature, from... Figure 8 As can be seen from this, at room temperature, 10 μA cm -2 The current density and cutoff capacitance are 100 μAh cm⁻¹. -2 The wide-temperature-range electrolyte prepared in Example 1 has better cycling performance compared with other examples, and can be stably cycled for about 1380 hours.

[0093] Figure 9 To illustrate the cycle performance of the lithium-carbon dioxide battery in Example 1 at low temperatures, from... Figure 9 As can be seen, under the low temperature condition of -30℃, the material of Example 1 has a 20μA cm⁻¹ temperature. -2 Cyclic performance at current density, with a cutoff capacity of 100 μAhcm. -2 It can stably cycle 79 times, approximately 790 hours.

[0094] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A wide-temperature-range electrolyte with an adjustable solvation energy barrier, characterized in that: Wide-temperature-range electrolytes include lithium salts, organic solvents, and ionic liquids, among which ionic liquids include imidazole ionic liquids and pyridine ionic liquids.

2. The wide-temperature-range electrolyte with adjustable solvation barrier according to claim 1, characterized in that: The lithium salt is at least one of inorganic anionic electrolyte lithium salt or organic anionic electrolyte lithium salt.

3. The wide-temperature-range electrolyte with adjustable solvation barrier according to claim 2, characterized in that: The lithium salt is at least one of bis(fluoromethanesulfonyl)imide lithium salt or bis(trifluoromethanesulfonyl)imide lithium salt.

4. The wide-temperature-range electrolyte with adjustable solvation barrier according to claim 1, characterized in that: The organic solvent is an aprotic polar solvent.

5. The wide-temperature-range electrolyte with adjustable solvation barrier according to claim 1, characterized in that: The organic solvent is at least one of tetraethylene glycol dimethyl ether or dimethyl sulfoxide.

6. The wide-temperature-range electrolyte with adjustable solvation barrier according to claim 1, characterized in that: The imidazole ionic liquid is at least one of 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide or 1-butyl-3-methylimidazolium tetrafluoroborate, and the pyridine ionic liquid is N-butyl-N-methylpyrrolidineonium bis(trifluoromethanesulfonyl)imide.

7. The wide-temperature-range electrolyte with adjustable solvation barrier according to claim 1, characterized in that: The concentration of lithium salt is 0.5–1.5 mol / L; The molar ratio of ionic liquid to organic solvent is 3:7; The molar ratio of imidazole ionic liquids to pyridine ionic liquids is (1-3):(1-3).

8. The method for preparing a wide-temperature-range electrolyte with adjustable solvation energy barrier according to any one of claims 1 to 7, characterized in that: Includes the following steps: (1) In a glove box filled with an inert atmosphere, imidazole ionic liquid and pyridine ionic liquid are mixed to obtain an ionic liquid; (2) Mix the ionic liquid with the organic solvent to obtain a mixture; (3) Add lithium salt to the mixture in batches, stir and sonicate until a transparent homogeneous solution is obtained, which is the wide temperature range electrolyte.

9. The application of the wide-temperature-range electrolyte with adjustable solvation energy barrier according to any one of claims 1 to 8, characterized in that: Application of wide-temperature-range electrolytes in lithium-carbon dioxide batteries.

10. The application of the wide-temperature-range electrolyte with adjustable solvation barrier according to claim 9, characterized in that: The electrode material in lithium-carbon dioxide batteries is a two-dimensional nanoelectrode material with negatively charged surface functional groups.

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