Electrolyte additive, electrolyte, alkali-chlorine secondary battery
By using specific electrolyte additives and electrolyte combinations in alkali metal-chlorine secondary batteries, the problem of loss of active chlorine species was solved, the electrochemical reaction kinetics were accelerated and the battery capacity was improved, resulting in high reversible capacity and cycle stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA UNIV OF PETROLEUM (BEIJING)
- Filing Date
- 2026-05-11
- Publication Date
- 2026-07-07
AI Technical Summary
In the reversible conversion process of alkali metal-chlorine secondary batteries, the loss of active chlorine species is severe, resulting in slow electrochemical reaction kinetics and limited capacity improvement.
An electrolyte additive with a specific formulation, containing components such as ethyl viologen dibromide, benzyl viologen diiodide, and 1,4-phenylenediamine hydroiodate, is combined with thionyl chloride, aluminum chloride, and fluorosulfonyl imide salt to form a fluorine-rich SEI film, which improves ionic conductivity and catalyzes the reversible conversion of chloride species.
It significantly improves charge transfer efficiency, accelerates electrochemical reaction kinetics, enhances reversible capacity and cycle stability, and strengthens the battery's environmental adaptability.
Smart Images
Figure CN122348321A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of alkali metal-chlorine secondary battery technology, specifically to electrolyte additives, electrolytes, and alkali metal-chlorine secondary batteries. Background Technology
[0002] With the continuous growth of global energy demand, energy storage technology has become a key to solving the energy crisis and achieving sustainable development.
[0003] With the increasing demand for low-cost, high-energy-density energy storage devices, the exploration of new battery technologies has become a research hotspot. Alkali metal ion batteries, represented by lithium-ion and sodium-ion batteries, have become the mainstream energy storage technology due to their high energy density.
[0004] Against this backdrop, alkali metal-chlorine secondary batteries are attracting widespread attention from researchers due to their combination of high energy density potential and low cost. This technology is inspired by high energy density (up to 710 Wh / kg). -1 The successful application of lithium thionyl chloride (Li-SOCl2) in primary batteries.
[0005] However, the lack of rechargeability in Li-SOCl2 primary batteries limits their application in scenarios requiring cyclic charging and discharging. To address this, Professor Dai Hongjie's team developed a novel lithium / sodium-chlorine secondary battery comprising a porous carbon cathode, a lithium metal / sodium anode, and an AlCl3 / SOCl2 / F-based SOCl2 electrolyte. This sodium-chlorine secondary battery exhibits a discharge voltage of 3.5V and a high mAh / g capacity. -1 With its reversible capacity (based on cathode mass), it can stably cycle more than 200 times, making it a battery system with great research value and development potential.
[0006] To date, research on alkali metal-chlorine secondary battery systems is still in its early stages, and the performance data reported in related reports remains poor. The reversible process involves multiple cascaded reactions (solid LiCl / NaCl and metallic Li / Na, gaseous Cl2, and intermediate reactants in the electrolyte). Each step reaction pathway is highly complex, and the loss of active chlorine species is significant. This results in slow electrochemical reaction kinetics for the battery system, severely limiting further increases in battery capacity. Summary of the Invention
[0007] The purpose of this invention is to overcome the problems of slow electrochemical reaction kinetics and limited capacity improvement in existing alkali metal-chlorine secondary batteries due to the severe loss of active chlorine species during the reversible conversion process.
[0008] To achieve the above objectives, a first aspect of the present invention provides an electrolyte additive containing components A, B, and C in a mass ratio of 1:0.2-2.0:0.5-3.0. Component A is selected from at least one of ethyl viologen dibromide, benzyl viologen diiodide, and 1,4-phenylenediamine hydroiodate; Component B is selected from at least one of 3-(4-iodophenyl)-3-(trifluoromethyl)-3H-bisacrylidine, 1-bromo-2-fluorobenzene, and 4-(benzyloxy)-1-bromo-2-fluorobenzene; The component C is selected from at least one of 3-(trifluoromethyl)phenyltrimethylammonium bromide, (3-fluoro-4-iodophenyl)methylamine, and 3-iodobenzylamine.
[0009] A second aspect of the present invention provides an electrolyte for an alkali metal-chlorine secondary battery, the electrolyte containing thionyl chloride, aluminum chloride, a fluorosulfonyl imide salt and an electrolyte additive; Based on the total mass of the electrolyte, the content of thionyl chloride is 75-90 wt%, the content of aluminum chloride is 5-25 wt%, the content of fluorosulfonyl imide salt is 1-6 wt%, and the content of electrolyte additives is 0.5-5.0 wt%. The electrolyte additive is the electrolyte additive described in the first aspect above.
[0010] A third aspect of the present invention provides an alkali metal-chlorine secondary battery, the secondary battery comprising a negative electrode, a positive electrode, an electrolyte, and a separator; The electrolyte is the electrolyte for alkali metal-chlorine secondary batteries described in the second aspect above.
[0011] Through the above technical solution, the present invention has at least the following advantages: (1) The electrolyte additive provided by the present invention, through a specific formulation design, can significantly improve charge transfer efficiency and accelerate electrochemical reaction kinetics when applied to the electrolyte of alkali metal-chlorine secondary batteries. On the other hand, it can be enriched on the positive electrode surface through electrostatic adsorption, efficiently catalyzing the reversible reaction of chlorine species and reducing the loss of chlorine species.
[0012] (2) The electrolyte provided by the present invention has the synergistic effect of thionyl chloride, aluminum chloride, fluorosulfonyl imide salt and electrolyte additive: AlCl3 improves ionic conductivity, fluorosulfonyl imide salt forms a fluorine-rich SEI film on the negative electrode to inhibit dendrite growth and avoid electrolyte corrosion, thereby improving battery coulombic efficiency and stable cycling.
[0013] (3) The electrolyte provided by the present invention can improve the conversion efficiency of chlorine species during the charging and discharging process when applied in the alkali metal-chlorine secondary battery system, and significantly improve the electrochemical reaction kinetics of the battery, and has high reversible capacity, cycle stability and environmental adaptability. Attached Figure Description
[0014] Figure 1 The image shows the charge-discharge curves of a sodium battery assembled with the electrolyte prepared in Example 1.
[0015] Figure 2 The charge-discharge curves of the lithium battery assembled with the electrolyte prepared in Test Example 2 are shown.
[0016] Figure 3 The charge-discharge curves of the sodium battery assembled with the electrolyte prepared in Comparative Example 1 are shown.
[0017] Figure 4 The charge-discharge curves of the sodium battery assembled with the electrolyte prepared in Comparative Example 2 are shown.
[0018] Figure 5 The graph shows a comparison of the cycling performance of sodium batteries assembled with the electrolytes prepared in Example 1 and Comparative Example 1 at 25°C.
[0019] Figure 6 The graph shows a comparison of the cycling performance of sodium batteries assembled with the electrolytes prepared in Example 1 and Comparative Example 1 at -20°C. Detailed Implementation
[0020] The endpoints and any values of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of the various ranges, the endpoint values of the various ranges and individual point values, and individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.
[0021] As previously described, a first aspect of the present invention provides an electrolyte additive containing components A, B, and C in a mass ratio of 1:0.2-2.0:0.5-3.0; Component A is selected from at least one of ethyl viologen dibromide, benzyl viologen diiodide, and 1,4-phenylenediamine hydroiodate; Component B is selected from at least one of 3-(4-iodophenyl)-3-(trifluoromethyl)-3H-bisacrylidine, 1-bromo-2-fluorobenzene, and 4-(benzyloxy)-1-bromo-2-fluorobenzene; The component C is selected from at least one of 3-(trifluoromethyl)phenyltrimethylammonium bromide, (3-fluoro-4-iodophenyl)methylamine, and 3-iodobenzylamine.
[0022] The electrolyte additive in this invention is essentially a compounded specific organic heterogeneous halogen compound, representing an integrated design at the molecular level. Through the ingenious combination of halogen elements and polar groups, it achieves an organic unity of three major functions: film formation, stability, and safety. Specifically, the heterogeneous halogen anions (I-, Br-) can generate interhalogen compounds, significantly enhancing the charge transfer kinetics of the alkali metal-chlorine secondary battery and achieving high reversible capacity. The organic framework in the additive can be enriched and arranged on the positive electrode surface through electrostatic adsorption, efficiently catalyzing the reversible transformation of chlorine species and improving electrochemical reaction kinetics. The fluorinated functional groups can synergistically construct a stable, low-impedance alkali metal negative electrode interface film, significantly enhancing the cycle life of the secondary lithium / sodium-chlorine battery under extreme environments.
[0023] Preferably, the electrolyte additive contains component A, component B, and component C in a mass ratio of 1:0.5-1.5:0.5-2.0. The inventors of this invention have discovered that, in this preferred embodiment, the electrolyte additive, when applied to the electrolyte of an alkali metal-chlorine secondary battery, can significantly improve charge transfer efficiency and accelerate the electrochemical reaction kinetics; furthermore, it can be enriched on the positive electrode surface through electrostatic adsorption, efficiently catalyzing the reversible transformation reaction of chlorine species and reducing the loss of chlorine species.
[0024] As mentioned above, a second aspect of the present invention provides an electrolyte for an alkali metal-chlorine secondary battery, the electrolyte containing thionyl chloride, aluminum chloride, a fluorosulfonyl imide salt and electrolyte additives. Based on the total mass of the electrolyte, the content of thionyl chloride is 75-90 wt%, the content of aluminum chloride is 5-25 wt%, the content of fluorosulfonyl imide salt is 1-6 wt%, and the content of electrolyte additives is 0.5-5.0 wt%. The electrolyte additive is the electrolyte additive described in the first aspect above.
[0025] The electrolyte of this invention contains a fluorosulfonyl imide salt, which provides the alkali metal ions required for the reaction, and the fluoride groups contained in the structure can generate an interface layer containing alkali metal fluorides on the electrode surface, preventing the electrolyte from corroding the electrode.
[0026] Preferably, the content of the electrolyte additive is 1-2 wt%, based on the total mass of the electrolyte. The inventors of this invention have discovered that, under this preferred condition, the chlorine species conversion efficiency during the charge-discharge process of the alkali metal-chlorine secondary battery is higher, the electrochemical reaction kinetics are more significantly improved, the cycle life is longer, and the low-temperature adaptability is stronger.
[0027] In a preferred embodiment, the fluorosulfonyl imide salt is a (fluorosulfonyl)(trifluoromethylsulfonyl)imide salt and a bis(pentafluoroethylsulfonyl)imide salt in a mass ratio of 1:0.5-2.0. The inventors of this invention have discovered that, in this preferred embodiment, a more stable and denser solid electrolyte interface (SEI) film can be formed, which more effectively suppresses dendrite growth during cycling, improves the cycle life and safety of the battery, and achieves a wider electrochemical stability window.
[0028] Preferably, the aluminum chloride content is 5-13 wt%, based on the total mass of the electrolyte. The inventors of this invention have discovered that, in this preferred embodiment, AlCl4 can be formed in the electrolyte. - It can form a continuous alkali metal ion transport network with polyanions; at the same time, it can form a specific solvation structure with alkali metal ions to improve the overall chemical stability of the electrolyte.
[0029] Preferably, the electrolyte for the alkali metal-chlorine secondary battery is prepared by a method comprising the following steps: In the presence of thionyl chloride, aluminum chloride, fluorosulfonyl imide salt and electrolyte additives are mixed to obtain the electrolyte for the alkali metal-chlorine secondary battery.
[0030] Preferably, the mixing conditions include: being carried out under magnetic stirring.
[0031] It should be noted that the present invention does not have special requirements for the magnetic stirring conditions, as long as the aluminum chloride, fluorosulfonyl imide salt and electrolyte additive are completely dissolved. The present invention will not elaborate further here, and those skilled in the art should not understand it as a limitation of the present invention.
[0032] Preferably, the mixing conditions further include: being carried out in a glove box environment filled with high-purity argon gas.
[0033] As mentioned above, a third aspect of the present invention provides an alkali metal-chlorine secondary battery, which includes a negative electrode, a positive electrode, an electrolyte, and a separator. The electrolyte is the electrolyte for alkali metal-chlorine secondary batteries described in the second aspect above.
[0034] Preferably, the positive electrode is selected from at least one of activated carbon, carbon black, carbon nanotubes, and mesoporous carbon.
[0035] Preferably, the mesoporous carbon has a specific surface area greater than 500 m². 2 / g, with a pore size range of 3.2-6.6nm.
[0036] In a preferred embodiment, the negative electrode is selected from lithium metal or sodium metal.
[0037] Preferably, the diaphragm is selected from at least one of glass fiber filter membrane and ceramic separator membrane.
[0038] This invention provides an exemplary assembly method for a sodium-chlorine secondary battery, comprising: (1) Preparation of positive electrode sheet In a glove box filled with high-purity argon, the positive electrode, conductive carbon (Super P) and binder polyvinylidene fluoride (PVDF) are mixed in a mass ratio of 7-9:0-1:1-3. N-methylpyrrolidone solvent is added, the electrode slurry is mixed evenly, and it is uniformly coated on a stainless steel current collector. The slurry is then dried in an oven at 75-85℃ to obtain the positive electrode sheet. (2) Assemble the battery Sodium metal sheets are placed inside the negative electrode shell, followed by a glass fiber filter membrane and sufficient electrolyte is added to wet it. The prepared positive electrode sheet is then placed on top of the separator, and after adding a gasket and spring sheet, the positive electrode shell is covered. Finally, the assembled battery is placed in a sealing machine to press and seal it, ensuring that the internal structure of the battery is tight and completely sealed, thus assembling a sodium-chlorine secondary battery.
[0039] Unless otherwise specified, room temperature in this invention refers to a temperature of 25±2℃.
[0040] The present invention will be described in detail below through examples. Unless otherwise specified, the instruments, reagents, and materials involved in the following examples are all conventional instruments, reagents, and materials, which can be obtained through legitimate commercial channels. Unless otherwise stated, all reagents used are commercially available analytical grade products.
[0041] All organic heterohalogen compounds in this invention are manufactured by Aladdin.
[0042] Electrolyte additives: Electrolyte Additive I: Benzyl violarin diiodide, 1-bromo-2-fluorobenzene, and 3-iodobenzylamine in a mass ratio of 1:1.0:0.8.
[0043] Electrolyte Additive II: Benzyl violarin diiodide, 3-(4-iodophenyl)-3-(trifluoromethyl)-3H-bisacrylidine, and (3-fluoro-4-iodophenyl)methylamine in a mass ratio of 1:0.5:1.0.
[0044] Electrolyte Additive III: 1,4-phenylenediamine hydroiodate, 4-(benzyloxy)-1-bromo-2-fluorobenzene, and 3-(trifluoromethyl)phenyltrimethylammonium bromide in a mass ratio of 1:1.2:2.0.
[0045] Electrolyte additive IV: benzyl viologen diiodide, 1-bromo-2-fluorobenzene, and 3-iodobenzylamine in a mass ratio of 1:1.8:3.0.
[0046] Electrolyte additive DI: benzyl violarin diiodide, 1-bromo-2-fluorobenzene, and 3-iodobenzylamine in a mass ratio of 1:0.05:0.20.
[0047] Fluorosulfonyl imide salts: Fluorosulfonyl imide salt I: sodium (fluorosulfonyl)(trifluoromethylsulfonyl)imide and sodium bis(pentafluoroethylsulfonyl)imide in a mass ratio of 1:1.5.
[0048] Fluorosulfonyl imide salt II: sodium bis(fluorosulfonyl imide) and sodium bis(trifluoromethylsulfonyl imide) in a mass ratio of 1:1.5.
[0049] In all the following examples, the sum of the masses of all components in the electrolyte is 2000 mg.
[0050] Example 1 This embodiment illustrates the preparation of the electrolyte according to the formulation in Table 1 and the following steps: In a glove box filled with high-purity argon, aluminum chloride, fluorosulfonyl imide salt I, and electrolyte additives are mixed in the presence of thionyl chloride (under magnetic stirring) to obtain an electrolyte for alkali metal-chlorine secondary batteries.
[0051] Example 2 This embodiment uses a method similar to that of Example 1, except for the electrolyte formulation; The parts not listed are the same as in Example 1. See Table 1 for details to obtain the electrolyte for alkali metal-chlorine secondary batteries.
[0052] Example 3 This embodiment uses a method similar to that of Example 1, except for the electrolyte formulation; The parts not listed are the same as in Example 1. See Table 1 for details to obtain the electrolyte for alkali metal-chlorine secondary batteries.
[0053] Example 4 This embodiment uses a method similar to that of Example 1, except for the electrolyte formulation; The parts not listed are the same as in Example 1. See Table 1 for details to obtain the electrolyte for alkali metal-chlorine secondary batteries.
[0054] Table 1
[0055] Note: All "wt%" in the table are based on the total mass of the electrolyte.
[0056] Example 5 This embodiment uses a method similar to that of Embodiment 1, except that, in the process of preparing the electrolyte, an equal weight of electrolyte additive IV is used to replace electrolyte additive I in Embodiment 1. The parts not listed are the same as in Example 1, and an electrolyte for alkali metal-chlorine secondary batteries is obtained.
[0057] Example 6 This embodiment is carried out using a method similar to that of Example 1. The difference is that, in the process of preparing the electrolyte, the fluorosulfonamide salt I in Example 1 is replaced with an equal weight of fluorosulfonamide salt II. The parts not listed are the same as in Example 1, and an electrolyte for alkali metal-chlorine secondary batteries is obtained.
[0058] Comparative Example 1 This comparative example was carried out using a method similar to that of Example 1, except that no electrolyte additives were added during the preparation of the electrolyte. The parts not listed are the same as in Example 1, and an electrolyte for alkali metal-chlorine secondary batteries is obtained.
[0059] Comparative Example 2 This comparative example was carried out using a method similar to that of Example 1. The difference was that, in the process of preparing the electrolyte, an equal weight of electrolyte additive DI was used to replace electrolyte additive I in Example 1. The parts not listed are the same as in Example 1, and an electrolyte for alkali metal-chlorine secondary batteries is obtained.
[0060] Test Example 1 The negative electrode electrolyte prepared in the above example was used to prepare a sodium-chlorine secondary battery. The specific method is as follows: (1) Preparation of positive electrode sheet In a glove box filled with high-purity argon, the positive electrode (specifically cubic b3d structure mesoporous carbon CMK-8, derived from Xianfeng Nano), conductive carbon (Super P), and binder polyvinylidene fluoride (PVDF) are mixed in a mass ratio of 8:1:1. N-methylpyrrolidone solvent is added, the electrode slurry is mixed evenly, and then uniformly coated onto a stainless steel current collector. The slurry is then dried in an 80°C oven to obtain the positive electrode sheet. (2) Assemble the battery Sodium metal sheets are placed inside the negative electrode shell, followed by a glass fiber filter membrane (purchased from Whatman, model 1823-047) and sufficient electrolyte is added to wet it. The prepared positive electrode sheet is then placed on top of the separator, and after adding the gasket and spring sheet, the positive electrode shell is covered. Finally, the assembled battery is placed in a sealing machine to press and seal it, ensuring that the internal structure of the battery is tight and completely sealed, thus assembling a button cell (model 2032).
[0061] The assembled battery is then subjected to battery performance testing. Cyclic performance testing was performed using the Blue Lightning testing system. Cyclic performance test parameters at 25℃: cutoff capacity is 500mA g -1 The current density is 1000 mA g -1 ; Cyclic performance test parameters at -20℃: cutoff capacity is 500mA g -1 The current density is 100 mA g -1 ; Reversibility test with different cutoff capacities: current density 500mA g -1 ; The test results are shown in Table 2.
[0062] Table 2
[0063] Test Example 2 A lithium-chlorine secondary battery is prepared using the following method: (1) Preparation of electrolyte The procedure was carried out using a method similar to that in Example 1, except that the fluorosulfonyl imide salt was lithium (fluorosulfonyl)(trifluoromethylsulfonyl)imide and lithium bis(pentafluoroethylsulfonyl)imide in a mass ratio of 1:1.5.
[0064] The parts not listed are the same as in Example 1. See Table 1 for details to obtain the electrolyte for lithium-chlorine secondary batteries.
[0065] (2) Preparation of positive electrode sheet In a glove box filled with high-purity argon, the positive electrode (specifically cubic b3d structure mesoporous carbon CMK-8, derived from Xianfeng Nano), conductive carbon (Super P), and binder polyvinylidene fluoride (PVDF) are mixed in a mass ratio of 8:1:1. N-methylpyrrolidone solvent is added, the electrode slurry is mixed evenly, and then uniformly coated onto a stainless steel current collector. The slurry is then dried in an 80°C oven to obtain the positive electrode sheet. (3) Assemble the battery The lithium metal sheet is placed inside the negative electrode shell, then a glass fiber filter membrane (purchased from Whatman, model 1823-047) is placed in it and sufficient electrolyte is added to wet it. The prepared positive electrode sheet is then placed on top of the separator, and after adding the gasket and spring sheet, the positive electrode shell is covered. Finally, the assembled battery is placed in a sealing machine to press and seal it, ensuring that the internal structure of the battery is tight and completely sealed, thus assembling a button cell (model 2032).
[0066] The assembled battery is then subjected to battery performance testing. Cyclic performance testing was performed using the Blue Lightning testing system. Cyclic performance test parameters at 25℃: cutoff capacity is 500mA g -1 The current density is 1000 mA g -1 ; Cyclic performance test parameters at -20℃: cutoff capacity is 500mA g -1 The current density is 100 mA g -1 ; Reversibility test with different cutoff capacities: current density 500mA g -1 ; The test results are shown in Table 3.
[0067] Table 3
[0068] This invention provides, by way of example, comparative charge-discharge curves of sodium-chlorine secondary batteries assembled using the electrolytes prepared in Example 1, Comparative Example 1, and Comparative Example 2, as shown in the figures below. Figure 1 , Figure 3 , Figure 4 As shown: pass Figure 1 It can be seen that the sodium-chlorine secondary battery assembled using the electrolyte prepared in Example 1 has a reversible specific capacity of up to 3000 mAh g. -1 Furthermore, the overpotential is only 0.33V, indicating that the specific electrolyte additive described in this invention can significantly accelerate the electrochemical reaction kinetics of the sodium-chlorine secondary battery. In contrast, Figure 3 The results showed that the sodium-chlorine secondary battery assembled using the electrolyte of Comparative Example 1 had a charge cutoff capacity set at 1500 mAh g. -1 At that time, the discharge capacity was only about 1400mAh g. -1 The reversibility decreased significantly and the overpotential was higher (0.649V). And from... Figure 4 It can be seen that the electrochemical performance of the sodium-chlorine secondary battery assembled in the other control system is between that of the two mentioned above.
[0069] This invention is in Figure 2 The example provides a comparison of charge-discharge curves of a lithium-chlorine secondary battery assembled with the electrolyte prepared in Test Example 2 above.
[0070] This invention is in Figure 5 The table provides an exemplary comparison of the 25°C cycle performance of sodium-chlorine secondary batteries assembled using the electrolytes in Example 1 and Comparative Example 1: pass Figure 5 It can be seen that the sodium-chlorine secondary battery prepared in Example 1 has a performance of 1000 mAg. -1At a current density of [specific value], the sodium-chlorine secondary battery can achieve stable cycling for 650 cycles without capacity decay; while the sodium-chlorine secondary battery prepared in Comparative Example 1 experiences rapid capacity decay until battery failure after 150 cycles. Therefore, the presence of the electrolyte additive provided by this invention significantly extends the cycle life of the sodium-chlorine secondary battery.
[0071] This invention is in Figure 6 The following is an exemplary comparison of the -20°C cycling performance of sodium-chlorine secondary batteries assembled using the electrolytes prepared in Example 1 and Comparative Example 1: pass Figure 6 It can be seen that the sodium-chlorine secondary battery prepared in Example 1 has a performance of 100 mA g -1 Under the current density and operating environment of -20℃, it can achieve stable cycling for more than 700 cycles without capacity decay; while the sodium-chlorine secondary battery prepared in Comparative Example 1 suddenly failed after 200 cycles. It can be seen that the presence of electrolyte additives provided by the present invention is beneficial to the sodium-chlorine secondary battery's tolerance to low temperature environment.
[0072] The above results demonstrate that the electrolyte additive provided by this invention has excellent application potential in alkali metal-chlorine secondary battery electrolytes. Applying the electrolyte provided by this invention to the alkali metal-chlorine secondary battery system significantly improves the electrochemical reaction kinetics of the battery, resulting in higher reversible capacity, cycle stability, and environmental adaptability.
[0073] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.
Claims
1. An electrolyte additive, characterized in that, The additive contains components A, B, and C in a mass ratio of 1:0.2-2.0:0.5-3.0; Component A is selected from at least one of ethyl viologen dibromide, benzyl viologen diiodide, and 1,4-phenylenediamine hydroiodate; Component B is selected from at least one of 3-(4-iodophenyl)-3-(trifluoromethyl)-3H-bisacrylidine, 1-bromo-2-fluorobenzene, and 4-(benzyloxy)-1-bromo-2-fluorobenzene; The component C is selected from at least one of 3-(trifluoromethyl)phenyltrimethylammonium bromide, (3-fluoro-4-iodophenyl)methylamine, and 3-iodobenzylamine.
2. The electrolyte additive according to claim 1, characterized in that, The electrolyte additive contains component A, component B, and component C in a mass ratio of 1:0.5-1.5:0.5-2.
0.
3. An electrolyte for alkali metal-chlorine secondary batteries, characterized in that, The electrolyte contains thionyl chloride, aluminum chloride, fluorosulfonyl imide salt, and electrolyte additives; Based on the total mass of the electrolyte, the content of thionyl chloride is 75-90 wt%, the content of aluminum chloride is 5-25 wt%, the content of fluorosulfonyl imide salt is 1-6 wt%, and the content of electrolyte additives is 0.5-5.0 wt%. The electrolyte additive is the electrolyte additive as described in claim 1 or 2.
4. The electrolyte according to claim 3, characterized in that, Based on the total mass of the electrolyte, the content of the electrolyte additive is 1-2 wt%.
5. The electrolyte according to claim 3 or 4, characterized in that, The fluorosulfonyl imide salt is a (fluorosulfonyl)(trifluoromethylsulfonyl) imide salt and a bis(pentafluoroethylsulfonyl) imide salt in a mass ratio of 1:0.5-2.
0.
6. The electrolyte according to claim 3 or 4, characterized in that, Based on the total mass of the electrolyte, the aluminum chloride content is 5-13 wt%.
7. An alkali metal-chlorine secondary battery, characterized in that, The secondary battery includes a negative electrode, a positive electrode, an electrolyte, and a separator; The electrolyte is the electrolyte for alkali metal-chlorine secondary batteries as described in any one of claims 3-6.
8. The alkali metal-chlorine secondary battery according to claim 7, characterized in that, The positive electrode is selected from at least one of activated carbon, carbon black, carbon nanotubes, and mesoporous carbon.
9. The alkali metal-chlorine secondary battery according to claim 7 or 8, characterized in that, The negative electrode is selected from lithium metal or sodium metal.
10. The alkali metal-chlorine secondary battery according to claim 7 or 8, characterized in that, The diaphragm is selected from at least one of glass fiber filter membrane and ceramic separator membrane.