An electrolyte for a lithium-air battery and a lithium-air battery

Abstract

This invention relates to the field of lithium-air battery electrolyte technology, specifically to an electrolyte for lithium-air batteries and a lithium-air battery. The electrolyte for lithium-air batteries comprises functional additives, lithium salts, and a solvent. The functional additives include tin tetrachloride and 1,8-diiodooctane, with the concentration of tin tetrachloride in the electrolyte being 0.01-0.1 mol / L and the concentration of 1,8-diiodooctane being 0.05-0.2 mol / L. During battery cycling, the electrolyte of this invention simultaneously achieves the dual functions of reducing overpotential through redox mediating and inhibiting dendrite growth by constructing an artificial SEI film in situ at the negative electrode, thereby achieving long-term protection of the lithium negative electrode and significantly improving the long-cycle stability of the battery, demonstrating very high practical value.

Description

Technical Field

[0001] This invention relates to the field of lithium-air battery electrolyte technology, specifically to an electrolyte for lithium-air batteries and a lithium-air battery. Background Technology

[0002] In recent years, with the rapid development of large-scale electrical equipment such as electric vehicles, the research and development of new high-energy battery systems that can replace lithium-ion batteries and meet the requirement of a driving range of >500 km on a single charge has become an urgent need for academia and industry. Lithium-air batteries, with their theoretical energy density approaching that of fossil fuels (~3500Wh / kg), offer a potential solution for these applications. The lithium-air battery system utilizes an ultra-high specific capacity lithium metal anode (3860mAh / g, -3.04V). vs The lithium-ion battery system (SHE) and open oxygen cathode (active material derived from ambient air) is a promising high-energy battery system. Its working mechanism is based on the reversible deposition / stripping of lithium metal on the negative electrode side and the reduction (ORR) and evolution (OER) of oxygen on the positive electrode side. However, the development of this system still faces many obstacles, such as: slow positive electrode oxygen reaction kinetics (ORR / OER), uncontrollable dendrite growth and interface corrosion of the lithium negative electrode, and insufficient stability of the electrolyte / electrode interface.

[0003] In recent years, redox mediators (RMs) have become a research hotspot in the field of lithium-air batteries. As mobile charge carriers dissolved in the electrolyte, RMs enhance battery performance through a dual mechanism: on the one hand, RMs can overcome spatial limitations and transfer charge between Li₂O₂ and the electrode, overcoming the solid-solid interface reaction barrier; on the other hand, RMs can reconstruct reaction pathways, altering the ORR / OER process without changing the final product morphology, ultimately achieving efficient homogeneous catalysis. LiI is one of the earliest and most widely used RMs, with a simple molecular structure and possessing I₂... - / I - 3 and I -The LiI redox couple (3 / I2) has two pairs of redox potentials, both of which are higher than the decomposition potential of Li2O2, making LiI an ideal candidate material for redox mediators (RMs). However, this same coin has two sides: the solubility of RMs also leads to their easy diffusion through the electrolyte to the lithium metal anode, triggering an irreversible shuttle effect—that is, unavoidable side reactions between RMs and the lithium anode. This process not only continuously consumes the liquid catalyst but also accelerates the corrosion of the lithium anode, ultimately severely damaging the cycle stability and energy efficiency of the battery. Therefore, it is urgent to develop effective strategies to suppress the shuttle effect of RMs. To avoid this shuttle effect and reduce catalyst loss, self-defense redox mediators have attracted widespread attention as an innovative strategy due to their catalytic-protective synergistic coupling mechanism: this electrolyte additive not only performs homogeneous catalysis but also induces the formation of a solid electrolyte interphase (SEI) in situ, thereby achieving dynamic suppression of the shuttle effect. Based on the above, introducing iodine-based self-defense RMs additives into the electrolyte, using iodine ions to reduce the overpotential of the battery during charging while forming an SEI film in situ on the surface of the negative electrode, is a simple and efficient strategy.

[0004] CN 120184362 A discloses a system for using 1,3-dimethylimidazolium iodide as an electrolyte redox additive in lithium-oxygen batteries. The cationic component of this additive can form a protective layer in situ on the lithium anode surface, effectively inhibiting lithium metal corrosion and dendrite growth, thereby significantly improving the long-cycle stability of the battery. However, the catalytic promoting effect of this type of additive on the oxygen reduction reaction process on the cathode side is relatively limited, failing to significantly enhance the overall oxygen reduction capability of the lithium-oxygen battery.

[0005] CN 112151862 B discloses the application of a class of halogenated imidazole compounds as redox additives. These compounds can significantly promote the formation and decomposition rate of Li₂O₂, thereby effectively reducing the overpotential of lithium-oxygen batteries. Simultaneously, they can form an SEI protective film in situ on the surface of the lithium metal anode, helping to suppress the shuttle effect and extend the battery's cycle life. However, the SEI film formed during this cycling process still lacks long-term stability, making it difficult to achieve sustained suppression of the shuttle effect.

[0006] CN 115275348 A discloses a strategy for using benzyl halides as additives in lithium-oxygen battery electrolytes. The iodine or bromide ions contained in these compounds can act as redox mediators, effectively reducing charging overpotential and improving reaction kinetics. Their benzyl structure can form an SEI film in situ on the lithium anode surface during cycling, thereby protecting the lithium metal anode and improving the battery's cycle stability and lifespan. However, when tested at a lower current, this system only operated stably for 116 cycles at a current density of 200 mA / g, indicating that the constructed organic SEI film may gradually fail as cycling progresses, failing to continuously and effectively protect the lithium anode during long-term cycling.

[0007] Although the aforementioned patents all utilize iodine-based self-defense redox mediators, which can reduce the overpotential of lithium-oxygen batteries while constructing an SEI in situ to protect the lithium anode and suppress the shuttle effect to some extent, their protective layers are mostly based on organic cations such as imidazole or benzyl. While the SEI formed by these organic components possesses good flexibility and deformation adaptability, its relatively limited mechanical strength makes it prone to cracking during long-term cycling, making it difficult to achieve long-term and effective protection for the lithium anode. Therefore, as cycling progresses, the shuttle effect often intensifies again, restricting the overall performance stability of the battery. This invention discloses an electrolyte for lithium-air batteries and a lithium-air battery, aiming to simultaneously achieve efficient homogeneous catalysis and improved anode interface stability. On the one hand, it uses iodine ions to reduce the charging overpotential; on the other hand, it forms a protective film with high lithium affinity and excellent corrosion resistance in situ on the lithium anode surface, which not only achieves long-term suppression of I- in the iodine-containing system... - / I - The self-discharge reaction triggered by diffusion to the negative electrode also greatly alleviates the corrosion of the lithium metal negative electrode by byproducts such as reactive oxygen species, resulting in a stable negative electrode interface. This significantly improves the reaction kinetics and cycle stability of the lithium-air battery, enabling the construction of a high-energy lithium-air battery system. Summary of the Invention

[0008] To address the shortcomings of existing lithium-air battery systems where redox mediators consume liquid-phase catalysts, accelerate lithium anode corrosion, and impair battery cycle stability and energy efficiency, this invention proposes an electrolyte for lithium-air batteries. This electrolyte uses tin tetrachloride and 1,8-diiodooctane (DIO) as additives, aiming to provide a lithium anode protection strategy that combines redox mediator function in lithium-air batteries. By introducing iodine-based components into the electrolyte, two core functions are simultaneously achieved: (1) reducing charge / discharge overpotential, playing a redox mediator role, and improving reaction kinetics; (2) constructing an anode protection layer, forming a barrier in situ on the lithium metal surface, effectively inhibiting the formation of I₂ in the iodine-containing system. - / I- 3. The self-discharge reaction initiated by diffusion to the negative electrode. This design significantly reduces If during charging. - The system reduces losses by 3%, simultaneously suppresses the shuttle effect, prevents lithium metal corrosion, and maintains the continuity of the oxidation reaction. Experiments show that the constructed lithium-air battery exhibits excellent electrochemical performance at 1000 mA g / L. -1 At high current density, the battery achieves an ultra-long cycle life of over 2400 cycles, with a discharge capacity of up to 111879 mAh g. -1 @100 mA g -1 This study verified the significant improvement in the long-cycle stability of the lithium-air battery system achieved by this method. Specifically, the present invention provides the following technical solution to address the aforementioned problems:

[0009] An electrolyte for lithium-air batteries includes a functional additive, a lithium salt, and a solvent. The functional additive includes tin tetrachloride and 1,8-diiodooctane, and the concentration of tin tetrachloride in the electrolyte is 0.01-0.1 mol / L, and the concentration of 1,8-diiodooctane is 0.05-0.2 mol / L.

[0010] Furthermore, the lithium salt is selected from at least one of lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium bis(fluorosulfonyl)imide, lithium perchlorate, and lithium nitrate.

[0011] Furthermore, in the electrolyte for the lithium-air battery, the concentration of lithium salt is 0.5-2M, preferably 0.8-1.5M, more preferably 0.9-1.2M, such as 1-1.1M.

[0012] Furthermore, the solvent is selected from at least one of tetraethylene glycol dimethyl ether, ethylene glycol dimethyl ether, N,N-dimethylacetamide, and propylene carbonate.

[0013] Furthermore, the concentration of tin tetrachloride in the electrolyte is 0.025-0.06 mol / L, and the concentration of 1,8-diiodooctane is 0.05-0.12 mol / L.

[0014] Furthermore, the concentration of tin tetrachloride in the electrolyte is 0.04-0.05 mol / L, and the concentration of 1,8-diiodooctane is 0.08-0.1 mol / L.

[0015] This invention protects the use of a composition of tin tetrachloride and 1,8-diiodooctane as an additive in lithium-air battery electrolytes.

[0016] Furthermore, in the electrolyte, the concentration of tin tetrachloride is 0.01-0.1 mol / L, the concentration of 1,8-diiodooctane is 0.05-0.2 mol / L, and the concentration of tin tetrachloride is 0.3-0.6 times that of 1,8-diiodooctane, preferably 0.4-0.5 times.

[0017] The present invention also provides a lithium-air battery, wherein the electrolyte comprises tin tetrachloride and 1,8-diiodooctane.

[0018] Furthermore, the concentration of tin tetrachloride in the electrolyte is 0.025-0.06 mol / L, and the concentration of 1,8-diiodooctane is 0.05-0.12 mol / L; even further, the concentration of tin tetrachloride in the electrolyte is 0.04-0.05 mol / L, and the concentration of 1,8-diiodooctane is 0.08-0.1 mol / L.

[0019] The inventors unexpectedly discovered that adding a certain amount of tin tetrachloride (SnCl4) and 1,8-diiodooctane (DIO) to the electrode solution of lithium-air batteries can significantly improve the long-cycle performance of lithium-air batteries, especially their long-cycle stability at high current densities. At a current density of 1000 mA / g, conventional lithium-air batteries with LiI as an additive rapidly polarize and fail after only 79 cycles. In contrast, the SnCl4 / DIO-based lithium-air battery of this invention exhibits superior long-cycle stability, achieving stable cycling for nearly 3000 hours at a low charging voltage of less than 3.5 V. Its cycle life is comparable to that of previously reported advanced lithium-air battery systems. Attached Figure Description

[0020] Figure 1 This is the XRD pattern of the negative electrode of the lithium-air battery in Example 1 after 10 cycles at 500 mA / g;

[0021] Figure 2 This is a high-resolution XPS image of the negative electrode of the lithium-air battery in Example 1 after 10 cycles at 500 mA / g;

[0022] Figure 3 The lithium-air battery of Example 1 was discharged to 30000 mAh g at 100 mA / g. -1 XPS spectrum of the positive electrode;

[0023] Figure 4 This is a SEM image of the negative electrode of the lithium-air battery in Example 1 after 10 cycles at 500 mA / g;

[0024] Figure 5 This is a characteristic ion fragment distribution map of the negative electrode surface of the lithium-air battery in Example 1 after 10 cycles at 500 mA / g;

[0025] Figure 6 This is a SEM image of the positive electrode of the lithium-air battery of Example 1 after cycling and full-capacity discharge at 1000 mA / g.

[0026] Figure 7 The lithium-lithium symmetric battery of Example 1 operates at 0.5 mA / cm². 2 Up to 10 mA / cm 2 Rate performance at lower speeds;

[0027] Figure 8 This is the deep discharge curve of the lithium-air battery in Example 1 at a current density of 100 mA / g;

[0028] Figure 9 This is a graph showing the changes in charge / discharge specific capacity and termination voltage of the lithium-air battery in Example 1 at 1000 mA / g with the number of cycles.

[0029] Figure 10 This is a SEM image of the negative electrode of the lithium-air battery obtained in Comparative Example 1 after 10 cycles at 500 mA / g.

[0030] Figure 11 This refers to the number of cycles tested on the lithium-air batteries of Comparative Examples 4-7 at a current density of 500 mA / g. Detailed Implementation

[0031] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0032] Example 1

[0033] (S1) The active material Super P and the binder (polyvinylidene fluoride) are mixed in NMP at a ratio of 4:1, ultrasonicated until well dispersed, uniformly coated on carbon paper, dried and cut into electrode sheets with a diameter of 14 mm, which are used as the positive electrode of lithium-air batteries.

[0034] (S2) Additives (0.05 M tin tetrachloride, 0.1 M 1,8-diiodooctane) and 1 M lithium salt LiTFSI are dissolved in solvent TEGDME to form a functional electrolyte; optionally, the stirring temperature is 25°C and the stirring time is 2-3 h.

[0035] (S3) Using the electrode sheet (positive electrode), lithium metal (negative electrode), and electrolyte prepared above, a lithium-air battery is assembled.

[0036] The lithium-air battery obtained in Example 1 was cycled 10 times at 500 mA / g. Figure 1 This is the XRD pattern of the negative electrode after 10 cycles. The characteristic peaks of lithium metal are clearly visible. Additionally, Li can also be observed. 13 Characteristic peaks of the (107), (201), and (202) crystal planes of Sn5. 13 Sn5, as an alloy phase, can have a crystal structure similar to Li. +It provides a low-barrier channel and reduces interfacial impedance. At the same time, the Sn component, as a lithiophilic component, can reduce the nucleation overpotential of lithium, which is beneficial for guiding uniform lithium deposition.

[0037] Figure 2 This is a high-resolution XPS image of the negative electrode of the lithium-air battery obtained in Example 1 after 10 cycles at 500 mA / g. It can be seen that the high-resolution Sn 3d XPS spectrum shows that there is significant Sn 3d content in the SEI protective layer. 3 / 2 and Sn 3d 5 / 2 The double peaks in the spin orbit indicate that during charging and discharging, Sn... 4+ Electrochemical migration can occur along the electric field direction from the cathode to the lithium metal anode, ultimately contributing to the construction of a dense and uniform SEI layer in the form of Sn-O materials and Li-Sn alloy phases. Simultaneously, high-resolution Cl 2p spectroscopy confirmed the presence of LiCl components in the SEI, which significantly promotes Li-metal exchange by enhancing interfacial ionic conductivity. + Based on the above results, the synergistic effect of LiCl and Li-Sn alloys can effectively optimize Li transport. + The diffusion kinetics in the SEI induce uniform deposition of lithium metal at the SEI / Li interface, while simultaneously suppressing the formation of lithium dendrites.

[0038] Figure 3 The lithium-air battery obtained in Example 1 was discharged to 30,000 mAh g at 100 mA / g. -1 XPS spectra of the positive electrode were obtained. The content of different elements on the electrode was investigated using XPS. The atomic ratio of Sn to Li in the discharge products was approximately 2:77, indicating that Sn doping entered the discharge products Li₂O₂, and the doping amount during the reaction was significantly lower than that of Li. + .

[0039] Figure 4 This is a SEM image of the negative electrode of the lithium-air battery obtained in Example 1 after 10 cycles at 500 mA / g. After 10 cycles, a distinct SEI layer formed on the surface of the lithium negative electrode, with a large number of nanoparticles and a thickness of approximately 25 μm. This indicates that a uniform, stable, continuous, and dense SEI film was formed in situ on the surface of the lithium negative electrode. This is beneficial for suppressing the uncontrolled growth of lithium dendrites and inhibiting the corrosion of the negative electrode by active oxygen, which is of great significance for constructing a stable lithium metal / electrolyte interface.

[0040] Figure 5 This is a time-of-flight secondary ion mass spectrometry (TOF-SIMS) distribution map of the negative electrode surface of the obtained lithium-air battery after 10 cycles at 500 mA / g. The characteristic ion fragment signals and their corresponding chemical compositions obtained by ToF-SIMS detection are as follows: LiSn - Corresponding to lithium-tin alloy (Li xSn), SnO - and SnO - The presence of tin oxides (including SnO and SnO2) was confirmed, indicating that Li-containing oxides with excellent lithium affinity were formed on the negative electrode surface. x Sn / Sn-O composite layer; CHO - 2. C2H - These components belong to the organic components, which originate from the organic polymer layer formed by the reaction of DIO additives at the electrode interface. This polymer layer possesses good ductility, effectively alleviating the rigidity of the inorganic components and synergistically enhancing the mechanical flexibility and deformation adaptability of the SEI layer, thereby buffering the volume change stress of the electrode during cycling; Furthermore, LiCl... - 2 and Cl - The signal clearly indicates the presence of LiCl. The accurate identification and spatial distribution analysis of these characteristic fragments provide crucial evidence for elucidating the chemical composition of the SEI layer, demonstrating the successful construction of a lithium metal surface containing organic polymers, LiCl, and lithiophilic LiCl. x Organic-inorganic composite interface layer including Sn / Sn-O materials.

[0041] Figure 6 This is a SEM image of the positive electrode of the lithium-air battery obtained in Example 1 after cycling and full-capacity discharge at 1000 mA / g. It can be seen that at 1000 mA / g... -1 At high current densities, Li2O2 products tend to form a continuous, relatively dense thin film on the electrode surface, spontaneously aggregating to form micron-sized porous spheres. This loose, porous stacking structure facilitates mass transport and is more easily formed and decomposed during charge and discharge, corresponding to the superior long-cycle performance of the lithium-air battery in this invention.

[0042] To evaluate the battery performance of this system, it was assembled into a coin cell. The positive and negative electrodes of the lithium-lithium symmetric battery both consist of lithium foil, with a glass fiber / D (GF / D) separator. The lithium-air battery was assembled using porous carbon paper (coated with Super P) as the positive electrode, lithium foil as the negative electrode, and a glass fiber / D (GF / D) separator. All battery assembly processes were completed in an argon-filled glove box using CR2032 coin cell casings.

[0043] 1. Assemble a lithium-lithium symmetric battery. Test parameters: Current density: 0.5 mA cm⁻¹ -2 1 mA cm -2 2 mA cm -2 5 mA cm -2 10 mA cm -2 Capacity: 1 mAh cm -2 .

[0044] 2. Assemble into a lithium-air battery. Test parameters: current density 1000 mA g -1 Limited capacity 500 mAh g -1 The voltage range is 2V to 4V. Relevant tests were conducted in a high-purity oxygen atmosphere (the evaluation system for lithium-air batteries). All current densities and specific capacities were calculated based on the mass of the loaded material.

[0045] Figure 7 It is a lithium-lithium symmetric battery at 0.5 mA cm⁻¹ -2 Up to 10 mA cm -2 The rate performance was measured. It can be seen that, compared to the battery without additives, the lithium-lithium symmetric battery using SnCl4 / DIO additives exhibits superior rate performance, indicating better lithium metal / electrolyte interface stability. Figure 8 It is a lithium-air battery at 100 mA g -1 The deep discharge curve at current density shows a discharge capacity as high as 111879 mAh g. -1 The discharge performance is significantly improved. Figure 9 It is a lithium-air battery at 1000mA g -1 The graph showing the changes in charge / discharge specific capacity and termination voltage with the number of cycles illustrates the long-cycle performance of the lithium-air battery of this invention. (At 1000 mA g) -1 At high current density, the battery achieves more than 2,400 stable cycles.

[0046] This superior performance stems from the dual functions of this electrolyte: 1. It constructs a protective layer on the lithium anode, effectively inhibiting lithium corrosion and dendrite growth (anode stabilization); 2. It significantly reduces charge / discharge overpotential (redox mediator). The synergistic effect of these two factors ultimately endows the battery with excellent long-cycle stability.

[0047] Example 2

[0048] The other conditions are the same as in Example 1, except that the electrolyte contains 0.025 M tin tetrachloride and 0.05 M 1,8-diiodooctane as additives.

[0049] Example 3

[0050] The other conditions are the same as in Example 1, except that the electrolyte contains 0.04 M tin tetrachloride and 0.08 M 1,8-diiodooctane as additives.

[0051] Comparative Example 1

[0052] The other conditions are the same as in Example 1, except that the additive in the electrolyte is 0.05 M LiI.

[0053] Figure 10 This is a SEM image of the negative electrode of the lithium-air battery obtained in Comparative Example 1 after 10 cycles at 500 mA / g. The negative electrode surface of the LiI-based lithium-air battery exhibits a rough and loose interfacial phase, with a large amount of by-product accumulation, attributed to Li during the cycling process. + The uneven deposition indicates that the lithium anode is affected by I - / I - 3. Severe corrosion from reactive oxygen species, etc.

[0054] Comparative Example 2

[0055] The other conditions are the same as in Example 1, except that the additive in the electrolyte is 0.15M tin tetrachloride.

[0056] Comparative Example 3

[0057] The other conditions are the same as in Example 1, except that the additive in the electrolyte is 0.15M 1,8-diiodooctane.

[0058] Comparative Example 4

[0059] The other conditions are the same as in Example 1, except that the electrolyte contains 0.05 M aluminum chloride and 0.1 M 1,8-diiodooctane as additives.

[0060] Comparative Example 5

[0061] The other conditions are the same as in Example 1, except that the electrolyte contains 0.05 M zinc chloride and 0.1 M 1,8-diiodooctane as additives.

[0062] Comparative Example 6

[0063] The other conditions are the same as in Example 1, except that the electrolyte additives are 0.05 M tin tetrachloride and 0.1 M 1,8-dibromooctane.

[0064] Comparative Example 7

[0065] The other conditions are the same as in Example 1, except that the electrolyte contains 0.05 M tin tetrachloride and 0.1 M 1,8-dichlorooctane as additives.

[0066] Table 1 shows the number of cycles required for the lithium-air batteries of the above embodiments and comparative examples to maintain a stable specific capacity under limited current density conditions.

[0067] Table 1. Number of cycles for lithium-air batteries

[0068] .

[0069] The batteries from Comparative Examples 4-7 were tested at a current density of 500 mA / g, and the results are as follows: Figure 11 As shown. (Compared to the embodiment) Figure 8 In comparison, it can be seen that at a lower current density, the number of cycles of the batteries in Comparative Examples 4-7 is far less than that in Example 1, indicating that the electrolyte additives in this invention, tin tetrachloride and 1,8-diiodooctane, can fully exert their synergistic effect.

Claims

1. An electrolyte for lithium-air batteries, comprising functional additives, lithium salts, and solvents, characterized in that, The functional additives include tin tetrachloride and 1,8-diiodooctane, and the concentration of tin tetrachloride in the electrolyte is 0.01-0.1 mol / L, and the concentration of 1,8-diiodooctane is 0.05-0.2 mol / L.

2. The electrolyte for lithium-air batteries according to claim 1, characterized in that, The lithium salt is selected from at least one of lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium bis(fluorosulfonyl)imide, lithium perchlorate, and lithium nitrate.

3. The electrolyte for lithium-air batteries according to claim 1, characterized in that, The concentration of lithium salt in the electrolyte for the lithium-air battery is 0.5-2M.

4. The electrolyte for lithium-air batteries according to claim 1, characterized in that, The solvent is selected from at least one of tetraethylene glycol dimethyl ether, ethylene glycol dimethyl ether, N,N-dimethylacetamide, and propylene carbonate.

5. The electrolyte for lithium-air batteries according to claim 1, characterized in that, The concentration of tin tetrachloride in the electrolyte is 0.025-0.06 mol / L, and the concentration of 1,8-diiodooctane is 0.05-0.12 mol / L.

6. The electrolyte for lithium-air batteries according to claim 1, characterized in that, The concentration of tin tetrachloride in the electrolyte is 0.04-0.05 mol / L, and the concentration of 1,8-diiodooctane is 0.08-0.1 mol / L.

7. Use of a combination of tin tetrachloride and 1,8-diiodooctane as an additive in lithium-air battery electrolytes.

8. The use according to claim 7, characterized in that, In the electrolyte, the concentration of tin tetrachloride is 0.01-0.1 mol / L, the concentration of 1,8-diiodooctane is 0.05-0.2 mol / L, and the concentration of tin tetrachloride is 0.3-0.6 times that of 1,8-diiodooctane.

9. A lithium-air battery, characterized in that, Its electrolyte contains 0.025-0.06 mol / L tin tetrachloride and 0.05-0.12 mol / L 1,8-diiodooctane.

10. The lithium-air battery according to claim 9, characterized in that, Its electrolyte contains 0.04-0.05 mol / L tin tetrachloride and 0.08-0.1 mol / L 1,8-diiodooctane.

Images