A non-aqueous aluminum ion electrolyte and a method for preparing the same

Abstract

The present application relates to a kind of non-aqueous aluminum ion electrolyte and its preparation method, belong to electrochemical energy storage technical field, including solute and solvent;The solute includes aluminum salt;The solvent includes alkyl ether solvent, chloro ether solvent, iodine alkyl solvent;Under inert gas, aluminum salt, alkyl ether solvent, chloro ether solvent, iodine alkyl solvent are mixed, stirring, obtain non-aqueous aluminum ion electrolyte.In the present application, the active chloro ether solvent is less, which avoids the corrosiveness to battery components, and at the same time, it relieves the corrosion to electrolyte-electrode interface phase, which is beneficial to form stable interface phase, and is compatible with high-voltage positive electrode material, so as to realize high-energy-density rechargeable aluminum metal battery system.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electrochemical energy storage technology, in particular to a non-aqueous aluminum ion electrolyte and a preparation method thereof. BACKGROUND

[0002] The electrolyte, as the bridge between the positive electrode and the negative electrode in the battery system, plays a decisive role in the transmission of active ions in the electrolyte body phase, the composition and structure of the electrode-electrolyte interface phase. At present, the aluminum ion electrolyte mainly uses aluminum chloride-chlorine-based imidazole ionic liquid, in which a large amount of free chlorine ions have a strong corrosive effect on the passivation layer of the electrode surface, so that the deposition of aluminum ions is not affected by the passivation layer. However, a large amount of free chlorine ions have serious corrosive effect, which can eliminate the beneficial interface phase while eliminating the passivation layer, which is not conducive to the formation of a stable interface phase, and can cause damage to the battery components such as aluminum metal negative electrode, metal current collector and stainless steel battery shell, thereby affecting the service life of the battery; at the same time, the oxidation stability of the electrolyte is poor, which is difficult to match with high-voltage positive electrode materials, and cannot realize high-energy-density rechargeable battery system.

[0003] Therefore, it is the key to break through the bottleneck of existing aluminum battery technology to develop a non-aqueous aluminum ion electrolyte with low corrosivity, stable interface and compatibility with high-voltage positive electrode. SUMMARY

[0004] The purpose of the present application is to provide a non-aqueous aluminum ion electrolyte and a preparation method thereof, which reduces the corrosivity to the beneficial interface phase and the battery components, and provides a new path for the commercialization of high-energy-density rechargeable aluminum metal batteries.

[0005] In one aspect, the present application provides a non-aqueous aluminum ion electrolyte, which adopts the following technical scheme:

[0006] A non-aqueous aluminum ion electrolyte, comprising a solute and a solvent;

[0007] The solute comprises an aluminum salt;

[0008] The solvent comprises an alkyl ether solvent, a chloroether solvent and an iodoalkane solvent.

[0009] Preferably, the aluminum salt is aluminum triflate.

[0010] Preferably, the alkyl ether solvent comprises any one of ethylene glycol dimethyl ether and diethylene glycol dimethyl ether.

[0011] Preferably, the chloroether solvent is any one of 1,2-bis(2-chloroethoxy)ethane, 2,2-dichloroether and diethylene glycol bis-chloroethyl ester.

[0012] Preferably, the iodinated alkane solvent is one of 1-iodobutane and 2-iodobutane.

[0013] Preferably, the molar concentration of the aluminum triflate is 0.1-1.0 mol / L.

[0014] Preferably, the volume concentration of the alkyl ether solvent is 10-60%;

[0015] The volume concentration of the chlorinated ether solvent is 40-80%;

[0016] The volume concentration of the iodinated alkane solvent is 0.05-0.50%.

[0017] In another aspect, the present application also provides a preparation method of the above-mentioned non-aqueous aluminum ion electrolyte, which adopts the following technical scheme:

[0018] A preparation method of a non-aqueous aluminum ion electrolyte, comprising,

[0019] Under inert gas, the aluminum salt, the alkyl ether solvent, the chlorinated ether solvent and the iodinated alkane solvent are mixed and stirred for 1 h to obtain the non-aqueous aluminum ion electrolyte.

[0020] In summary, the present application has the following beneficial technical effects:

[0021] 1) The aluminum salt in the present application provides aluminum ions, which, as the main active ingredient of the electrolyte, undergoes aluminum deposition / dissolution at the negative electrode side, undergoes intercalation / extraction or other reversible aluminum ion storage reactions at the positive electrode side; the alkyl ether solvent serves as a solvent to dissolve the aluminum salt; the chlorinated ether solvent provides chemical chlorine, which, compared with free chlorine, has relatively moderate chemical activity, thereby avoiding strong corrosiveness to the battery components, alleviating the corrosion to the electrolyte-electrode interface phase, being conducive to the formation of a stable interface phase, thereby prolonging the cycle life of the battery, and the chlorinated ether solvent is stable, the electrochemical window of the electrolyte prepared therefrom is wide, and high-voltage positive electrode materials can be compatible, so as to realize a high-energy-density rechargeable aluminum metal battery system; meanwhile, the iodinated alkane solvent can induce the formation of a stable iodine-containing electrode-electrolyte interface phase.

[0022] 2) The non-aqueous aluminum ion electrolyte prepared in the present application can be stably cycled for more than 500 hours at a low potential of less than 1 V. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 is the constant current charge-discharge curve of the electrolyte prepared in Example 1 of the present application.

[0024] Figure 2 is the constant current charge-discharge curve of the electrolyte prepared in Example 2 of the present application.

[0025] Figure 3 is a constant current charge-discharge curve of the electrolyte prepared in Example 3 of the present application.

[0026] Figure 4 is a constant current charge-discharge curve of the electrolyte prepared in Comparative Example 1 of the present application.

[0027] Figure 5 is a constant current charge-discharge curve of the electrolyte prepared in Comparative Example 2 of the present application. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the following will combine the accompanying drawings to make a detailed description. Figures 1-3 The technical solutions of the present application are described clearly and completely, obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0029] EMBODIMENT

[0030] EMBODIMENT 1

[0031] The present embodiment 1 provides a non-aqueous aluminum ion electrolyte, comprising a solute and a solvent; the solute comprises an aluminum salt, and the aluminum salt is aluminum triflate; the solvent comprises an alkyl ether solvent, a chloro ether solvent and an iodoalkane solvent, wherein the alkyl ether solvent is ethylene glycol dimethyl ether, the chloro ether solvent is 1,2-bis(2-chloroethoxy)ethane, and the iodoalkane solvent is 1-iodobutane.

[0032] The molar concentration of the aluminum triflate is 0.2 M.

[0033] The volume concentration of the alkyl ether solvent is 49.95%.

[0034] The volume concentration of the chloro ether solvent is 49.95%.

[0035] The volume concentration of the iodoalkane solvent is 0.10%.

[0036] When calculating the molar concentration of the aluminum triflate, 10 μL of 1-iodobutane is ignored.

[0037] In the present embodiment 1, in an argon atmosphere glove box, 0.948 g of aluminum triflate, 5 mL of diethylene glycol dimethyl ether, 5 mL of 1,2-bis(2-chloroethoxy)ethane and 10 μL of 1-iodobutane are added into a glass vial, and then magnetically stirred at room temperature for 1 hour to obtain a non-aqueous aluminum ion electrolyte.

[0038] EMBODIMENT 2

[0039] The embodiment 2 provides a non-aqueous aluminum ion electrolyte, comprising a solute and a solvent; the solute comprises an aluminum salt, and the aluminum salt is aluminum triflate; the solvent comprises an alkyl ether solvent, a chloro ether solvent and an iodoalkane solvent; the alkyl ether solvent is ethylene glycol dimethyl ether, the chloro ether solvent is diethylene glycol bis-chloroethyl ether, and the iodoalkane solvent is 2-iodobutane.

[0040] The molar concentration of the aluminum triflate is 0.6M.

[0041] The volume concentration of the alkyl ether solvent is 49.90%.

[0042] The volume concentration of the chloro ether solvent is 49.90%.

[0043] The volume concentration of the iodoalkane solvent is 0.20%.

[0044] When the molar concentration of the aluminum triflate is calculated, 20μL of the 2-iodobutane is ignored.

[0045] In the embodiment 2, 2.845 g of aluminum triflate, 5 mL of ethylene glycol dimethyl ether, 5 mL of diethylene glycol bis-chloroethyl ether and 20μL of 2-iodobutane are added into a glass vial in an argon atmosphere glove box, and magnetically stirred at room temperature for 1 hour to obtain the non-aqueous aluminum ion electrolyte.

[0046] Embodiment 3

[0047] The embodiment 3 provides a non-aqueous aluminum ion electrolyte, comprising a solute and a solvent; the solute comprises an aluminum salt, and the aluminum salt is aluminum triflate; the solvent comprises an alkyl ether solvent, a chloro ether solvent and an iodoalkane solvent; the alkyl ether solvent is ethylene glycol dimethyl ether, the chloro ether solvent is 1,2-bis(2-chloroethoxy)ethane, and the iodoalkane solvent is 1-iodobutane.

[0048] The molar concentration of the aluminum triflate is 0.1M.

[0049] The volume concentration of the alkyl ether solvent is 19.94%.

[0050] The volume concentration of the chloro ether solvent is 79.76%.

[0051] The volume concentration of the iodoalkane solvent is 0.30%.

[0052] When the molar concentration of the aluminum triflate is calculated, 30μL of the 1-iodobutane is ignored.

[0053] In this Example 3, in an argon atmosphere glove box, 0.474 g aluminum triflate, 2 mL ethylene glycol dimethyl ether, 8 mL 1,2-bis(2-chloroethoxy)ethane, 30 μL 1-iodobutane were added into a glass vial, and magnetically stirred at room temperature for 1 hour to obtain a non-aqueous aluminum ion electrolyte.

[0054] Example 4

[0055] This Example 4 provides a non-aqueous aluminum ion electrolyte, comprising a solute and a solvent; the solute comprises an aluminum salt, and the aluminum salt is aluminum triflate; the solvent comprises an alkyl ether solvent, a chloro ether solvent, and an iodoalkane solvent; the alkyl ether solvent is ethylene glycol dimethyl ether, the chloro ether solvent is 2,2-dichloroethanol, and the iodoalkane solvent is 1-iodobutane.

[0056] The molar concentration of the aluminum triflate is 0.5 M.

[0057] The volume concentration of the alkyl ether solvent is 39.96%.

[0058] The volume concentration of the chloro ether solvent is 59.94%.

[0059] The volume concentration of the iodoalkane solvent is 0.10%.

[0060] In the calculation of the molar concentration of the aluminum triflate, 10 μL of 1-iodobutane is ignored.

[0061] In this Example 4, in an argon atmosphere glove box, 2.371 g aluminum triflate, 4 mL ethylene glycol dimethyl ether, 6 mL 2,2-dichloroethanol, 10 μL 1-iodobutane were added into a glass vial, and magnetically stirred at room temperature for 1 hour to obtain a non-aqueous aluminum ion electrolyte.

[0062] Example 5

[0063] This Example 5 provides a non-aqueous aluminum ion electrolyte, comprising a solute and a solvent; the solute comprises an aluminum salt, and the aluminum salt is aluminum triflate; the solvent comprises an alkyl ether solvent, a chloro ether solvent, and an iodoalkane solvent; the alkyl ether solvent is ethylene glycol dimethyl ether, the chloro ether solvent is 1,2-bis(2-chloroethoxy)ethane, and the iodoalkane solvent is 2-iodobutane.

[0064] The molar concentration of the aluminum triflate is 0.8 M.

[0065] The volume concentration of the alkyl ether solvent is 59.94%.

[0066] The volume concentration of the chloro ether solvent is 39.96%.

[0067] The volume concentration of the iodinated alkyl ether solvent is 0.10%;

[0068] The molar concentration of the aluminum triflate is 0.1 M, and 10 μL of 2-iodobutane is ignored in the calculation.

[0069] In this embodiment 5, in an argon atmosphere glove box, 3.792 g of aluminum triflate, 6 mL of diethylene glycol dimethyl ether, 4 mL of 1,2-bis(2-chloroethoxy)ethane, and 10 μL of 2-iodobutane were added into a glass vial, and magnetically stirred at room temperature for 1 hour to obtain a non-aqueous aluminum ion electrolyte.

[0070] Embodiment 6

[0071] This embodiment 6 provides a non-aqueous aluminum ion electrolyte, which comprises a solute and a solvent; the solute comprises an aluminum salt, and the aluminum salt is aluminum triflate; the solvent comprises an alkyl ether solvent, a chlorinated ether solvent, and an iodinated alkyl solvent; the alkyl ether solvent is diethylene glycol dimethyl ether, the chlorinated ether solvent is 1,2-bis(2-chloroethoxy)ethane, and the iodinated alkyl solvent is 1-iodobutane.

[0072] The molar concentration of the aluminum triflate is 0.1 M.

[0073] The volume concentration of the alkyl ether solvent is 29.85%.

[0074] The volume concentration of the chlorinated ether solvent is 69.65%.

[0075] The volume concentration of the iodinated alkyl ether solvent is 0.50%.

[0076] The molar concentration of the aluminum triflate is 0.1 M, and 10 μL of 2-iodobutane is ignored in the calculation.

[0077] In this embodiment 6, in an argon atmosphere glove box, 0.474 g of aluminum triflate, 3 mL of diethylene glycol dimethyl ether, 7 mL of 1,2-bis(2-chloroethoxy)ethane, and 50 μL of 2-iodobutane were added into a glass vial, and magnetically stirred at room temperature for 1 hour to obtain a non-aqueous aluminum ion electrolyte.

[0078] Comparative Example

[0079] Comparative Example 1

[0080] This comparative example 1 provides an electrolyte, which comprises a solute and a solvent; the solute comprises an aluminum salt, and the aluminum salt is aluminum triflate; the solvent comprises an alkyl ether solvent, and the alkyl ether solvent is diethylene glycol dimethyl ether.

[0081] The molar concentration of the aluminum triflate is 0.4 M.

[0082] The volume concentration of the alkyl ether solvent is 100%.

[0083] In Comparative Example 1, 0.948 g of aluminum triflate, 10 mL of diethylene glycol dimethyl ether were added into a glass vial and magnetically stirred at room temperature for 1 hour to obtain an electrolyte under an argon atmosphere in a glove box.

[0084] Comparative Example 2

[0085] Comparative Example 2 provides an electrolyte comprising a solute and a solvent; the solute comprises an aluminum salt, and the aluminum salt is aluminum triflate, an iodoalkane solvent; the solvent comprises an alkyl ether solvent, and the alkyl ether solvent is diethylene glycol dimethyl ether, and the iodoalkane solvent is 1-iodobutane.

[0086] The molar concentration of aluminum triflate is 0.4 M.

[0087] The volume concentration of the alkyl ether solvent is 99.80%.

[0088] The volume concentration of the iodoalkane solvent is 0.20%.

[0089] The molar concentration of aluminum triflate is 0.4 M.

[0090] In Comparative Example 2, 0.948 g of aluminum triflate, 10 mL of diethylene glycol dimethyl ether and 20 μL of 1-iodobutane were added into a glass vial and magnetically stirred at room temperature for 1 hour to obtain an electrolyte under an argon atmosphere in a glove box.

[0091] Test Example

[0092] Eight groups of experimental groups were set up respectively. Aluminum foil was used as the working electrode and the counter electrode, glass fiber was used as the separator, and the electrolytes of the eight groups of experimental groups were the electrolytes prepared by Examples 1-6 and Comparative Examples 1-2, respectively. CR2025 type button cells were assembled, and constant current charge-discharge tests were carried out at a current density of 0.1 mA cm –2 at a capacity of 0.05 mAh cm –2 .

[0093] Test Results Refer to Figures 1-5 , Figure 1 is the constant current charge-discharge curve of the electrolyte prepared in Example 1, and the test results show that the electrolyte prepared in Example 1 can be stably cycled for more than 500 hours at a low overpotential of less than 1 V; Figure 2 is the constant current charge-discharge curve of the electrolyte prepared in Example 2, and the test results show that the electrolyte prepared in Example 2 can be stably cycled for more than 500 hours at a low overpotential of less than 1 V; Figure 3is the constant current charge-discharge curve diagram of the electrolyte prepared by the embodiment 3 of the present application, and the test result shows that the electrolyte prepared by the embodiment 3 of the present application can be stably cycled for more than 300 hours under a low overpotential of less than 1V; Figure 4 is the constant current charge-discharge curve diagram of the electrolyte prepared by the comparative example 1 of the present application, and the test result shows that the aluminum deposition / dissolution overpotential of the electrolyte prepared by the comparative example 1 of the present application exceeds 5V within 2 hours, triggering the underpotential protection, and the electrolyte does not have the performance of aluminum deposition / dissolution; Figure 5 is the constant current charge-discharge curve diagram of the electrolyte prepared by the comparative example 2 of the present application, and the test result shows that the aluminum deposition / dissolution overpotential of the electrolyte prepared by the comparative example 2 of the present application is large, and the high-energy-density aluminum metal battery system cannot be realized.

[0094] In addition, the electrolyte prepared by the embodiment 4 of the present application can be stably cycled for more than 400 hours under a low overpotential, and the overpotential is less than 1V; the electrolyte prepared by the embodiment 5 of the present application can be stably cycled for more than 300 hours under a low overpotential, and the overpotential is less than 1V; and the electrolyte prepared by the embodiment 6 of the present application can be stably cycled for more than 300 hours under a low overpotential, and the overpotential is less than 1V.

[0095] The above are preferred embodiments of the present application, and are not intended to limit the protection scope of the present application, so: any equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A non-aqueous aluminum-ion electrolyte, characterized by, The solute comprises an aluminum salt; The solute comprises an aluminum salt; The solvent comprises an alkyl ether solvent, a chloro ether solvent, and an iodoalkane solvent; The alkyl ether solvent comprises any one of ethylene glycol dimethyl ether and diethylene glycol dimethyl ether; The chloro ether solvent is any one of 1,2-bis(2-chloroethoxy)ethane, 2,2-dichloroethyl ether, and diethylene glycol bis-chloroethyl ester; The iodoalkane solvent is any one of 1-iodobutane and 2-iodobutane.

2. The nonaqueous aluminum-ion electrolyte according to claim 1, wherein The aluminum salt is aluminum triflate.

3. The nonaqueous aluminum-ion electrolyte according to claim 2, wherein The molar concentration of the aluminum triflate is 0.1-1.0 mol / L.

4. The nonaqueous aluminum-ion electrolyte according to claim 1, wherein The volume concentration of the alkyl ether solvent is 10-60%; The volume concentration of the chloro ether solvent is 40-80%; The volume concentration of the iodoalkane solvent is 0.05-0.50%.

5. A method for producing the non-aqueous aluminum electrolyte solution according to any one of claims 1 to 4, characterized by, The solute comprises an aluminum salt; The solute comprises an aluminum salt; The solvent comprises an alkyl ether solvent, a chloro ether solvent, and an iodoalkane solvent; The alkyl ether solvent comprises any one of ethylene glycol dimethyl ether and diethylene glycol dimethyl ether; The chloro ether solvent is any one of 1,2-bis(2-chloroethoxy)ethane, 2,2-dichloroethyl ether, and diethylene glycol bis-chloroethyl ester; The iodoalkane solvent is any one of 1-iodobutane and 2-iodobutane. The aluminum salt is aluminum triflate. The molar concentration of the aluminum triflate is 0.1-1.0 mol / L. The volume concentration of the alkyl ether solvent is 10-60%; The volume concentration of the chloro ether solvent is 40-80%; The volume concentration of the iodoalkane solvent is 0.05-0.50%. The solute comprises an aluminum salt; The solute comprises an aluminum salt; The solvent comprises an alkyl ether solvent, a chloro ether solvent, and an iodoalkane solvent; The alkyl ether solvent comprises any one of ethylene glycol dimethyl ether and diethylene glycol dimethyl ether; The chloro ether solvent is any one of 1,2-bis(2-chloroethoxy)ethane, 2,2-dichloroethyl ether, and diethylene glycol bis-chloroethyl ester; The iodoalkane solvent is any one of 1-iodobutane and 2-iodobutane. The aluminum salt is aluminum triflate. The molar concentration of the aluminum triflate is 0.1-1.0 mol / L. The volume concentration of the alkyl ether solvent is 10-60%; The volume concentration of the chloro ether solvent is 40-80%; The volume concentration of the iodoalkane solvent is 0.05-0.50%. The solute comprises an aluminum salt; The solute comprises an aluminum salt; The solvent comprises an alkyl ether solvent, a chloro ether

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