A lithium-carbon dioxide battery
By using carbon nanotubes loaded with ruthenium nanoparticles and a dual-solvent electrolyte in lithium-carbon dioxide batteries, the formation of lithium oxalate was promoted, thus solving the decomposition kinetics problem of lithium-carbon dioxide batteries and achieving high electrochemical performance and long cycle life.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XIAN UNIV OF SCI & TECH
- Filing Date
- 2026-04-01
- Publication Date
- 2026-06-19
AI Technical Summary
The lithium carbonate formed during the discharge process of lithium-carbon dioxide batteries has slow decomposition kinetics, resulting in low operating voltage and poor cycle life, making it difficult to achieve excellent electrochemical performance.
Using carbon nanotube-supported ruthenium nanoparticles as the cathode material and employing a dual-solvent electrolyte of tetraethylene glycol dimethyl ether and dimethyl sulfoxide to promote the formation of lithium oxalate and improve the battery's decomposition kinetics and cycle stability.
It significantly improves the electrochemical performance of lithium-carbon dioxide batteries, achieving a discharge specific capacity of 13595 mAh g-1, a charge-discharge plateau at 2.90 V, and stable cycling for over 1500 h.
Smart Images
Figure CN122246272A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of battery technology, specifically relating to a lithium-carbon dioxide battery. Background Technology
[0002] Lithium-carbon dioxide (Li-CO2) batteries have attracted widespread attention due to their high energy density and potential for utilizing CO2 as a reactant. However, the lithium carbonate (Li2CO3) formed during discharge exhibits slow decomposition kinetics, resulting in low operating voltage (<2.5V) and poor cycle life, making it difficult to achieve excellent electrochemical performance. Therefore, improving the electrochemical performance of lithium-carbon dioxide batteries has become a pressing technical challenge in this field. Summary of the Invention
[0003] The purpose of this invention is to provide a lithium-carbon dioxide battery. The lithium-carbon dioxide battery provided by this invention possesses excellent electrochemical performance.
[0004] The present invention provides a lithium-carbon dioxide battery, wherein the positive electrode material of the lithium-carbon dioxide battery includes carbon nanotubes and ruthenium nanoparticles supported on the carbon nanotubes; The electrolyte of the lithium-carbon dioxide battery includes lithium salt and solvent; The solvents include tetraethylene glycol dimethyl ether and dimethyl sulfoxide.
[0005] Preferably, the carbon nanotubes have a diameter of 10-25 nm and a length of 5-10 μm.
[0006] Preferably, the size of the ruthenium nanoparticles is 4~8 nm.
[0007] Preferably, the method for preparing the positive electrode material includes the following steps: (1) Carbon nanotubes and ruthenium salt solution were mixed and loaded to obtain a precursor solution; (2) The precursor solution obtained in step (1) is subjected to a reduction reaction to obtain the cathode material.
[0008] Preferably, the ruthenium salt in the ruthenium salt solution in step (1) includes ruthenium chloride or ruthenium acetylacetonate.
[0009] Preferably, the temperature of the load in step (1) is room temperature, and the loading time is 0.5~2h.
[0010] Preferably, the temperature of the reduction reaction in step (2) is 120~200℃ and the time of the reduction reaction is 1~3h.
[0011] Preferably, the lithium salt comprises lithium bis(trifluoromethanesulfonyl)imide or lithium hexafluorophosphate.
[0012] Preferably, the concentration of the electrolyte is 0.5~2 mol / L.
[0013] Preferably, the mass ratio of tetraethylene glycol dimethyl ether to dimethyl sulfoxide is 1:(1~3).
[0014] This invention provides a lithium-carbon dioxide battery. The positive electrode material of the lithium-carbon dioxide battery includes carbon nanotubes and ruthenium nanoparticles supported on the carbon nanotubes. The electrolyte of the lithium-carbon dioxide battery includes a lithium salt and a solvent. The solvent includes tetraethylene glycol dimethyl ether and dimethyl sulfoxide. This invention promotes the formation of the discharge product lithium oxalate (Li₂C₂O₄) through the synergistic effect of the positive electrode material and the electrolyte. The formation of lithium oxalate significantly improves the decomposition kinetics of the battery, thereby enhancing the electrochemical performance of the battery. Furthermore, the use of a dual-solvent electrolyte improves the stability of the lithium anode, further enhancing the cycle stability and electrochemical kinetics of the battery. Experimental results show that the lithium-carbon dioxide battery provided by this invention has a discharge specific capacity of 13595 mAh g⁻¹. -1 The charge / discharge platform is at 2.90 V, and it can cycle stably for more than 1500 hours. Attached Figure Description
[0015] Figure 1 The discharge specific capacity curves of the lithium-carbon dioxide batteries prepared in Example 1 and Comparative Examples 1-3 are shown. Figure 2 The cycling performance curves of the lithium-carbon dioxide batteries prepared in Example 1 and Comparative Examples 1-2 are shown. Figure 3 The charge-discharge plateau and polarization curves of the lithium-carbon dioxide batteries prepared in Example 1 and Comparative Examples 1-2 are shown. Figure 4 The XRD patterns of the lithium-carbon dioxide battery charge-discharge products prepared in Example 1 and Comparative Examples 1-2 are shown below. Figure 5 SEM images of the charge-discharge products of the lithium-carbon dioxide battery prepared in Example 1; Figure 6 SEM images of the charge-discharge products of the lithium-carbon dioxide battery prepared in Comparative Example 1. Figure 7 SEM images of the charge-discharge products of the lithium-carbon dioxide battery prepared in Comparative Example 2. Figure 8 The curves show the lithium metal deposition / stripping in the electrolytes used in Example 1 and Comparative Examples 1 and 2. Detailed Implementation
[0016] The present invention provides a lithium-carbon dioxide battery, wherein the positive electrode material of the lithium-carbon dioxide battery includes carbon nanotubes and ruthenium nanoparticles supported on the carbon nanotubes; The electrolyte of the lithium-carbon dioxide battery includes lithium salt and solvent; The solvents include tetraethylene glycol dimethyl ether and dimethyl sulfoxide.
[0017] Unless otherwise specified, the present invention does not have any special limitations on the source of the raw materials used, and commercially available products or well-known preparation methods familiar to those skilled in the art can be used.
[0018] In this invention, the positive electrode material of the lithium-carbon dioxide battery comprises carbon nanotubes and ruthenium nanoparticles supported on the carbon nanotubes. In this invention, the positive electrode material acts as a catalyst, promoting the formation of the discharge product lithium oxalate (Li₂C₂O₄). The formation of lithium oxalate significantly improves the battery's decomposition kinetics, thereby enhancing the battery's electrochemical performance.
[0019] In this invention, the diameter of the carbon nanotube is preferably 10-25 nm; the length of the carbon nanotube is preferably 5-10 μm; and the size of the ruthenium nanoparticles is preferably 4-8 nm.
[0020] In this invention, the method for preparing the positive electrode material preferably includes the following steps: (1) Carbon nanotubes and ruthenium salt solution were mixed and loaded to obtain a precursor solution; (2) The precursor solution obtained in step (1) is subjected to a reduction reaction to obtain the cathode material.
[0021] In this invention, carbon nanotubes and ruthenium salt solution are mixed and loaded to obtain a precursor solution.
[0022] In this invention, the carbon nanotubes are preferably pretreated before use; the pretreatment is preferably performed by immersing the carbon nanotubes in a solvent; the solvent is preferably ethanol or acetone; the pretreatment temperature is preferably room temperature; and the pretreatment time is preferably 1-3 hours. This pretreatment method enables the carbon nanotubes to be evenly dispersed.
[0023] As one implementation method, the preprocessing time can be 2 hours.
[0024] In this invention, the ruthenium salt in the ruthenium salt solution preferably includes ruthenium chloride (RuCl3·xH2O) or ruthenium acetylacetonate; the solvent of the ruthenium salt solution is preferably water; and the concentration of the ruthenium salt solution is preferably 0.05~0.5 mol / L. As one embodiment, the concentration of the ruthenium salt solution can be 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, or 0.4 mol / L. In this invention, the ruthenium salt solution is a precursor to ruthenium nanoparticles.
[0025] In this invention, the preferred mass ratio of the carbon nanotubes to the ruthenium salt solution is (1~3):(7~9), and more preferably 2:8.
[0026] The present invention does not have any special limitations on the operation of mixing the carbon nanotubes and ruthenium salt solution; any technical solution for preparing the mixture well known to those skilled in the art can be used.
[0027] In this invention, the temperature of the loading is preferably room temperature; the loading time is preferably 0.5 to 2 hours. As one embodiment, the loading time can be 1 hour or 1.5 hours. Limiting the loading time to the above range in this invention can increase the loading amount and ensure that ruthenium nanoparticles are uniformly adsorbed on carbon nanotubes, thereby improving the catalytic effect.
[0028] In this invention, the load is preferably applied under ultrasonic conditions; the ultrasonic power is preferably 40-60 W. As one embodiment, the ultrasonic power can be 45 W, 50 W, or 55 W.
[0029] After obtaining the precursor solution, the present invention preferably performs a reduction reaction on the precursor solution to obtain the cathode material.
[0030] In this invention, the preferred temperature for the reduction reaction is 120-200°C, and the preferred reaction time is 1-3 hours. As one embodiment, the temperature for the reduction reaction can be 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, or 190°C; and the reaction time can be 2 hours. By limiting the process parameters of the reduction reaction within the above ranges, this invention can improve the degree of reduction, enabling the ruthenium particles to be reduced to a nanoscale state.
[0031] After the reduction reaction is completed, the present invention preferably filters the product obtained from the reduction reaction to obtain the cathode material.
[0032] The present invention does not impose any special limitations on the filtration operation; the filter membrane can be obtained by using an operation well known to those skilled in the art.
[0033] In this invention, the electrolyte of the lithium-carbon dioxide battery comprises a lithium salt and a solvent; the lithium salt preferably comprises lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) or lithium hexafluorophosphate; the solvent comprises tetraethylene glycol dimethyl ether (TEGDME) and dimethyl sulfoxide (DMSO). This invention employs a dual-solvent electrolyte, which improves the stability of the lithium anode and further enhances the battery's cycle stability and electrochemical kinetics.
[0034] In this invention, the preferred mass ratio of tetraethylene glycol dimethyl ether to dimethyl sulfoxide is 1:(1~3). As one embodiment, the mass ratio of tetraethylene glycol dimethyl ether to dimethyl sulfoxide can be 1:2. Limiting the mass ratio of tetraethylene glycol dimethyl ether to dimethyl sulfoxide within the above range further improves the electrochemical performance of lithium-carbon dioxide batteries.
[0035] In this invention, the concentration of lithium salt in the electrolyte is preferably 0.5~2 mol / L. As one embodiment, the concentration of lithium salt in the electrolyte can be 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L, 1 mol / L, 1.1 mol / L, 1.2 mol / L, 1.3 mol / L, 1.4 mol / L, 1.5 mol / L, 1.6 mol / L, 1.7 mol / L, 1.8 mol / L, or 1.9 mol / L. Limiting the concentration of lithium salt in the electrolyte within the above range further improves the electrochemical performance of the lithium-carbon dioxide battery.
[0036] The present invention does not impose any special limitation on the preparation method of the electrolyte; any preparation method well known to those skilled in the art can be used.
[0037] The present invention does not impose any special limitations on other components and structures in the lithium-carbon dioxide battery; any components and structures well known to those skilled in the art can be used.
[0038] In one embodiment, the negative electrode of the lithium-carbon dioxide battery can be lithium; the separator of the lithium-carbon dioxide battery can be at least one of glass fiber and polypropylene; the battery casing of the lithium-carbon dioxide battery can be one of CR2025, CR2032, CR2450, CR2016 and CR2330; the battery casing has a side opening; the shape of the battery casing can be one of coin type, flat type and laminated type.
[0039] The combination of the cathode material and electrolyte in this invention promotes the formation of lithium oxalate during discharge. Lithium oxalate exhibits superior decomposition kinetics compared to traditional lithium carbonate, thereby significantly improving battery reversibility and cycle life. After using the electrolyte, the battery achieves a high capacity of 13595 mAh g / L. -1It has a reversible discharge specific capacity, and the battery operates stably for more than 1500 hours in cycle testing.
[0040] The electrolyte provided by this invention helps stabilize the lithium anode and improves the electrochemical kinetics of lithium-carbon dioxide batteries, enabling lithium-carbon dioxide batteries to exhibit higher reversible discharge specific capacity and longer cycle life during charge and discharge compared to using a single solvent electrolyte.
[0041] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.
[0042] Example 1 A lithium-carbon dioxide battery, wherein the positive electrode material is carbon nanotubes and ruthenium nanoparticles (i.e. Ru nanoparticles) loaded on the carbon nanotubes. The electrolyte is LiTFSI and a solvent; the solvent is TEGDME and DMSO. The method for preparing the cathode material is as follows: (1) Carbon nanotubes with a diameter of 10~25nm and a length of 5~10μm were pretreated by immersing them in acetone for 1h, then removed and mixed with 0.1mol / L RuCl3·xH2O solution. The mixture was then loaded at room temperature under ultrasonic conditions of 40W for 1h to obtain a precursor solution. The mass ratio of carbon nanotubes to RuCl3·xH2O solution was 2:8. (2) The precursor solution obtained in step (1) is subjected to a reduction reaction in an oil bath at 180°C for 3 hours, and then filtered to obtain the cathode material (i.e., Ru NPs@CNT). The electrolyte is prepared by: LiTFSI was dissolved in TEGDME and DMSO in a mass ratio of 1:1 to obtain an electrolyte with a lithium salt concentration of 1 mol / L. The negative electrode is lithium; The diaphragm is made of glass fiber and has a thickness of 40 μm; The battery casing is made of CR2032. The battery casing has a side opening; The battery casing is coin-shaped. The lithium-carbon dioxide battery was placed in a carbon dioxide atmosphere.
[0043] Example 2 Based on Example 1, the mass ratio of TEGDME and DMSO was changed to 1:2, while other conditions remained unchanged.
[0044] Example 3 Based on Example 1, the mass ratio of TEGDME and DMSO was changed to 1:3, while other conditions remained unchanged.
[0045] The lithium-carbon dioxide batteries prepared in Examples 1-3 were used with a current density of 200 mA g. -1 A constant current was used for charge and discharge testing.
[0046] The results showed that the discharge specific capacity of the lithium-carbon dioxide battery prepared in Example 1 was 13595 mAh g⁻¹. -1 The charge / discharge plateau is at 2.90 V, and it can be stably cycled for over 1500 h. The lithium-carbon dioxide battery prepared in Example 2 has a discharge specific capacity of 10830 mAh g. -1 The charge / discharge plateau is at 2.85 V, and the stable cycle performance is slightly inferior at 1000 h; the discharge specific capacity of the lithium-carbon dioxide battery prepared in Example 3 is 8540 mAh g. -1 The charge / discharge platform is at 2.75 V, and the stable cycle time is 500 h.
[0047] The test results of Examples 1-3 show that a mass ratio of TEGDME to DMSO of 1:1 can further improve the electrochemical performance of lithium-carbon dioxide batteries, and maintain low polarization and stable charge-discharge performance after 1500h.
[0048] Comparative Example 1 Based on Example 1, only TEGDME was used, while other conditions remained unchanged.
[0049] Comparative Example 2 Based on Example 1, only DMSO was used, while other conditions remained unchanged.
[0050] Comparative Example 3 Based on Example 1, the cathode material is made of carbon nanotubes, while other conditions remain unchanged.
[0051] The lithium-carbon dioxide batteries prepared in Example 1 and Comparative Examples 1-3 were used with a current density of 200 mA g. -1 A constant current charge-discharge test was performed, and the results are as follows: Figures 1-3 As shown.
[0052] Figure 1 The discharge specific capacity curves of the lithium-carbon dioxide batteries prepared in Example 1 and Comparative Examples 1-3 are shown. Figure 2The cycling performance curves of the lithium-carbon dioxide batteries prepared in Example 1 and Comparative Examples 1-2 are shown. Figure 3 The charge-discharge plateau and polarization curves of the lithium-carbon dioxide batteries prepared in Example 1 and Comparative Examples 1-2 are shown.
[0053] from Figures 1-3 It can be seen that the lithium-carbon dioxide battery provided by the present invention has excellent cycle stability and electrochemical performance, and has a stable voltage platform during charging and discharging.
[0054] The charge-discharge products of the lithium-carbon dioxide batteries prepared in Example 1 and Comparative Examples 1 and 2 were characterized by XRD and SEM, and the results are as follows: Figures 4-7 As shown.
[0055] Figure 4 The images show the XRD patterns of the lithium-carbon dioxide battery charge-discharge products prepared in Example 1 and Comparative Examples 1-2.
[0056] from Figure 4 It can be seen that only the lithium-carbon dioxide battery prepared in Example 1 generated lithium oxalate instead of lithium carbonate (Li2CO3) during discharge, which proves that the dual-solvent electrolyte helps to optimize the formation of reaction products.
[0057] Figure 5 SEM images of the charge-discharge products of the lithium-carbon dioxide battery prepared in Example 1; Figure 6 SEM images of the charge-discharge products of the lithium-carbon dioxide battery prepared in Comparative Example 1. Figure 7 SEM images of the charge-discharge products of the lithium-carbon dioxide battery prepared in Comparative Example 2.
[0058] from Figures 5-7 It can be seen that the lithium-carbon dioxide battery charge-discharge products prepared in Example 1 exhibit the morphological characteristics of lithium oxalate, indicating that its decomposition kinetics are superior.
[0059] Li / Li symmetric cells were assembled using the electrolytes from Example 1 and Comparative Examples 1 and 2, at a temperature of 0.1 mA cm⁻¹. -2 / 0.1mAh cm -2 The stability of lithium deposition / stripping was measured, and the results are as follows: Figure 8 As shown, Figure 8 The curves show the lithium metal deposition / stripping in the electrolyte in Example 1 and Comparative Examples 1 and 2.
[0060] from Figure 8 It can be seen that lithium in dual-solvent electrolytes has a longer cycle life, which helps to improve battery performance.
[0061] As can be seen from the above embodiments and comparative examples, the lithium-carbon dioxide battery provided by the present invention has excellent electrochemical performance.
[0062] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A lithium-carbon dioxide battery, characterized in that, The positive electrode material of the lithium-carbon dioxide battery includes carbon nanotubes and ruthenium nanoparticles supported on the carbon nanotubes. The electrolyte of the lithium-carbon dioxide battery includes lithium salt and solvent; The solvents include tetraethylene glycol dimethyl ether and dimethyl sulfoxide.
2. The lithium-carbon dioxide battery according to claim 1, characterized in that, The carbon nanotubes have a diameter of 10-25 nm and a length of 5-10 μm.
3. The lithium-carbon dioxide battery according to claim 1, characterized in that, The ruthenium nanoparticles have a size of 4-8 nm.
4. The lithium-carbon dioxide battery according to claim 1, characterized in that, The method for preparing the cathode material includes the following steps: (1) Carbon nanotubes and ruthenium salt solution were mixed and loaded to obtain a precursor solution; (2) The precursor solution obtained in step (1) is subjected to a reduction reaction to obtain the cathode material.
5. The lithium-carbon dioxide battery according to claim 4, characterized in that, The ruthenium salt in the ruthenium salt solution in step (1) includes ruthenium chloride or ruthenium acetylacetonate.
6. The lithium-carbon dioxide battery according to claim 4, characterized in that, In step (1), the temperature of the load is room temperature, and the loading time is 0.5~2h.
7. The lithium-carbon dioxide battery according to claim 4, characterized in that, The temperature of the reduction reaction in step (2) is 120~200℃, and the time of the reduction reaction is 1~3h.
8. The lithium-carbon dioxide battery according to claim 1, characterized in that, The lithium salt includes lithium bis(trifluoromethanesulfonyl)imide or lithium hexafluorophosphate.
9. The lithium-carbon dioxide battery according to claim 1, characterized in that, The concentration of lithium salt in the electrolyte is 0.5~2 mol / L.
10. The lithium-carbon dioxide battery according to claim 1, characterized in that, The mass ratio of the tetraethylene glycol dimethyl ether to dimethyl sulfoxide is 1:(1~3).