AlCl3-based chloride solid electrolyte and preparation method thereof
By using AlCl3 and Li2O to prepare xLi2O-AlCl3 solid electrolyte, the safety hazards and high cost of traditional lithium-ion batteries are solved, realizing a low-cost, high-performance all-solid-state battery electrolyte and simplifying the preparation process.
Patent Information
- Application Number
- CN202511708163.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-20
- Publication Date
- 2026-02-27
AI Technical Summary
The organic liquid electrolyte used in traditional lithium-ion batteries poses safety risks, and the raw materials for traditional metal chloride solid electrolytes are expensive and the synthesis process is complex, which limits the development of all-solid-state batteries.
By using inexpensive and readily available AlCl3 to replace expensive raw materials, xLi2O-AlCl3 solid electrolyte is prepared by combining Li2O and AlCl3 and employing a simple ball milling method. The material composition is optimized to obtain high ionic conductivity and good interfacial stability.
A low-cost, high-performance solid electrolyte with a room-temperature ionic conductivity of no less than 0.24 mS/cm has been achieved, reducing production costs and simplifying the fabrication process, thus meeting the application requirements of all-solid-state batteries.
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Figure CN121584007A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the field of solid electrolytes, and particularly relates to a chloride solid electrolyte based on AlCl3 and a preparation method thereof. BACKGROUND
[0002] With the rapid development of electric vehicles, large-scale energy storage and consumer electronics, more stringent requirements are put forward for the energy density, safety performance and working temperature range of lithium ion batteries. Traditional lithium ion batteries use organic liquid electrolytes, which have inherent safety hazards such as easy leakage, flammability and explosiveness, seriously restricting the further development of battery technology. All-solid-state lithium batteries use non-flammable solid electrolytes to replace liquid electrolytes, which are considered as the next generation of electrochemical energy storage technology to fundamentally solve the safety problem of batteries and achieve a leap in energy density.
[0003] Among various solid electrolytes, inorganic solid electrolytes have become the research focus due to their non-flammability, high mechanical strength and wide electrochemical window. Among them, chloride solid electrolytes are an important class of materials that have emerged in recent years. They usually exhibit high ionic conductivity comparable to sulfide electrolytes, and have excellent interface stability to high-voltage positive electrode materials, avoiding the gas production and side reaction problems of sulfides, and showing great application potential.
[0004] However, the raw materials InCl3, YCl3 and ErCl3 used in traditional metal chloride solid electrolytes are too expensive, which limits the development of metal chloride solid electrolytes. Although ZrCl4-based metal chloride solid electrolytes have reduced the cost to some extent, the exploration of lower-cost materials is still the focus of current research. In addition, the synthesis process of some chloride electrolytes is complex, often requiring long-time high-temperature sintering or complex wet chemical processes, further increasing the production cost and process complexity.
[0005] Therefore, it has become a key technical problem to be solved for promoting the industrialization of all-solid-state batteries to develop a new type of chloride solid electrolyte with excellent ionic conductivity, good interface stability, low-cost raw materials and simple preparation process. SUMMARY
[0006] In view of the above technical problems, the application provides a chloride solid electrolyte based on AlCl3 and a preparation method thereof. The chloride solid electrolyte based on AlCl3 is obtained by compounding Li2O and AlCl3, and is a low-cost, high-ionic-conductivity chloride solid electrolyte.
[0007] The application provides a low-cost novel solid electrolyte, which fundamentally reduces the raw material cost of the solid electrolyte by replacing expensive traditional metal chloride solid electrolyte raw materials with cheap and readily available AlCl3.
[0008] The AlCl3-based chloride solid electrolyte developed by the application has excellent lithium ion conductivity (not less than 0.24 mS / cm), which ensures excellent electrochemical performance and ensures its practical performance in a full solid-state battery.
[0009] The preparation method is a simple and efficient preparation method which does not require complex equipment or a long high-temperature process, and the target electrolyte can be prepared by a simple ball milling method, thereby further reducing the production cost and improving the preparation efficiency.
[0010] The application optimizes the material composition, and finds the optimal composition with the best conductivity and phase stability by accurately controlling the molar ratio (xLi2O-AlCl3, 0.5≤x≤2.5) of Li2O and AlCl3.
[0011] The application achieves the above technical purpose through the following technical means.
[0012] An AlCl3-based chloride solid electrolyte has a general chemical formula of xLi2O-AlCl3, wherein x represents a molar ratio coefficient of Li2O and AlCl3, the general chemical formula xLi2O-AlCl3 represents a composite material formed by the composite reaction of x moles of Li2O and 1 mole of AlCl3, and 0.5≤x≤2.5.
[0013] In the above scheme, in xLi2O-AlCl3, the value of x is 0.5, 1, 1.5, 2 and 2.5, preferably, the value of x is 2.
[0014] In the above scheme, the room temperature ionic conductivity of the AlCl3-based chloride solid electrolyte is not less than 0.24 mS / cm.
[0015] A preparation method of the AlCl3-based chloride solid electrolyte comprises the following steps: Step S1, under an inert gas protection atmosphere, weighing Li2O and AlCl3 raw materials according to the stoichiometric ratio of the general chemical formula; Step S2, placing the weighed Li2O and AlCl3 raw materials in a sealed ball mill pot together with ball milling balls for ball milling reaction to obtain a ball milling product; Step S3, tabletting the ball milling product of step S2 under an inert gas protection atmosphere to obtain the AlCl3-based chloride solid electrolyte.
[0016] In the above scheme, in the step S1 and the step S3, the protective atmosphere is argon.
[0017] In the above scheme, in the step S2, the total mass ratio of the ball mill ball and the raw material (ball-to-material ratio) is (9-13):1.
[0018] In the above scheme, in the step S2, the ball milling speed is 500-600 rpm, and the total ball milling time is 200-600 min; the ball milling is intermittent ball milling, specifically, after each continuous ball milling for 5-30 min, the ball milling is paused and cooled for 5-10 min.
[0019] In the above scheme, in the step S2, the ball milling speed is 600 rpm, and the ball milling time is 300 min; after each continuous ball milling for 10 min, the ball milling is paused and cooled for 5 min.
[0020] In the above scheme, in the step S3, the pressure for tabletting is 500-700 MPa.
[0021] In the above scheme, in the step S3, the pressure for tabletting is 600 MPa.
[0022] Compared with the prior art, the present application has the following advantages: 1. The present application obtains an AlCl3-based chloride solid-state electrolyte by compounding Li2O and AlCl3, and the inorganic chloride-based solid-state electrolyte has a chemical formula of xLi2O-AlCl3, wherein 0.5≤x≤2.5, and has the advantages of low cost and excellent ionic conductivity; the Li2O and AlCl3 in the present application can be synthesized by simple ball milling, and the preparation method of the AlCl3-based solid-state electrolyte in the present application has the advantages of simple raw materials, easy to obtain, simple process, and low cost.
[0023] 2. The present application uses inexpensive AlCl3 to replace the expensive raw materials of traditional metal chloride solid-state electrolytes. According to the calculation, the raw material cost of the solid-state electrolyte (such as 2 Li2O-AlCl3 with the optimal composition) in the present application can be as low as about 1219 yuan / kg, which is much lower than the cost of traditional zirconium-based chloride electrolyte (the cost of ZrCl4-based solid-state electrolyte is usually 2564 yuan / kg, which is much higher than that of AlCl3), and the raw material cost of the present application is significantly reduced, which fundamentally reduces the raw material cost of the solid-state electrolyte.
[0024] 3. The application obtains a solid-state electrolyte by optimizing the ratio of Li2O to AlCl3, which exhibits excellent lithium ion conductivity. In particular, at the optimal composition (x=2), the room temperature ion conductivity can reach 0.24 mS / cm, the ion conductivity is high, the performance is excellent, and the application requirements of solid-state batteries are fully met, realizing the balance of low cost and high performance.
[0025] 4. The application adopts a one-step mechanical ball milling method, which is simple in process, does not require high-temperature sintering or complex subsequent treatment required for traditional solid-state electrolyte synthesis, has a short preparation process, is efficient and low in energy consumption, has low requirements for equipment, and further reduces the overall production cost.
[0026] 5. The entire synthesis process is carried out near room temperature, avoiding side reactions and element volatilization that may occur at high temperatures, which is conducive to obtaining stable amorphous products. The full reaction and compounding between raw materials can be realized by simple ball milling, and the process reproducibility is good. BRIEF DESCRIPTION OF DRAWINGS
[0027] Figure 1 is the XRD pattern of xLi2O-AlCl3of an embodiment of the application; Figure 2 is the room temperature impedance spectrum of xLi2O-AlCl3of an embodiment of the application; Figure 3 is the room temperature ion conductivity graph of xLi2O-AlCl3of an embodiment of the application; Figure 4 is the temperature-dependent impedance spectrum of 2Li2O-AlCl3of an embodiment of the application; Figure 5 is the activation energy calculation of 2Li2O-AlCl3of an embodiment of the application. DETAILED DESCRIPTION
[0028] The embodiments of the application will be described in detail below, and the embodiments described by reference to the accompanying drawings are exemplary and are intended to explain the application, and cannot be understood as limiting the application. The experimental methods used in the following examples are conventional methods unless otherwise specified; the reagents, materials, etc. used in the following examples can be obtained from commercial channels unless otherwise specified. The application will be further described below in conjunction with the examples, and Example 4 is the best embodiment of the application. Example 1
[0029] A preparation method of an AlCl3-based chloride solid-state electrolyte, comprising the following steps: Step S1, under inert gas protection atmosphere, Li2O and AlCl3 raw materials are weighed according to the stoichiometric ratio of the chemical formula; specifically, 0.299 g of Li2O and 2.667 g of AlCl3 are weighed, and it can be calculated that the synthesized sample of this embodiment is 0.5Li2O-AlCl3.
[0030] Step S2, the Li2O and AlCl3 raw materials weighed in step S1 are placed in a sealed ball mill pot together with the ball mill balls to carry out a ball milling reaction to obtain a ball milling product; specifically, 10 zirconia large balls and 30 small balls are used to form the ball milling balls, wherein the diameter of the large balls is 10 mm, the diameter of the small balls is 3 mm, and the ball-to-raw material ratio (total mass ratio of balls to raw materials) is 13:1. The above ball milling raw materials and ball milling balls are added to a zirconia ball mill pot and sealed, and ball milling is carried out at a speed of 600 rpm for 300 min. During the ball milling process, the ball mill stops cooling for 5 min every 10 min of continuous ball milling; the ball milling product is obtained.
[0031] Step S3, the ball milling product of step S2 is tabletted under inert gas protection atmosphere to obtain an AlCl3-based chloride solid-state electrolyte; specifically, the ball milling product in step S2 is taken out under argon protection atmosphere, and part of the powder is tested for XRD. Under argon protection atmosphere, tabletting is directly formed in a tablet press at a pressure of 600 MPa to obtain an AlCl3-based chloride solid-state electrolyte, and the room temperature impedance is tested.
[0032] As shown in Figure 1 , the XRD data of 0.5Li2O-AlCl3 indicates that the 0.5Li2O-AlCl3 sample is amorphous. Figure 2 The room temperature impedance spectrum of 0.5Li2O-AlCl3 was tested using an electrochemical workstation model (SP-50e, Bio-Logic) at 25°C, with a frequency range from 1000 KHz to 1 Hz and a voltage of 5 mV. The calculated room temperature ionic conductivity of 0.5Li2O-AlCl3 is 0.0031 mS / cm, as shown in Figure 3 . Example 2
[0033] A method for preparing an AlCl3-based chloride solid-state electrolyte, comprising the following steps: Step S1, under inert gas protection atmosphere, Li2O and AlCl3 raw materials are weighed according to the stoichiometric ratio of the chemical formula; specifically, 0.299 g of Li2O and 2.667 g of AlCl3 are weighed, and it can be calculated that the synthesized sample of this embodiment is 0.5Li2O-AlCl3.
[0034] Step S2, the weighed Li2O and AlCl3 raw materials in step S1 are placed in a sealed ball mill jar together with the ball mill balls to perform a ball milling reaction to obtain a ball milling product; specifically, 10 zirconia large balls and 30 small balls are taken to form the ball mill balls, wherein the diameter of the large balls is 10 mm, the diameter of the small balls is 3 mm, and the ball-to-material ratio (total mass ratio of balls to raw materials) is 12:1. The above ball milling raw materials and ball mill balls are added to the ball mill jar and sealed, and ball milling is performed at a speed of 600 rpm for 300 min. During the ball milling process, the ball mill is stopped and cooled for 5 min every 10 min of continuous ball milling. The ball milling product is obtained.
[0035] Step S3, the ball milling product in step S2 is tabletted under an inert gas protective atmosphere to obtain an AlCl3-based chloride solid-state electrolyte; specifically, the ball milling product in step S2 is taken out under an argon protective atmosphere, and part of the powder is tested for XRD. The AlCl3-based chloride solid-state electrolyte is directly tabletted in a tablet press under a pressure of 600 MPa in an argon protective atmosphere, and the room temperature impedance is tested.
[0036] As shown in Figure 1 , the XRD data of 1Li2O-AlCl3 indicates that the 1Li2O-AlCl3 sample is mainly amorphous, accompanied by a small amount of Li2O phase. Figure 2 The room temperature impedance spectrum of 1Li2O-AlCl3 was measured using an electrochemical workstation model (SP-50e, Bio-Logic) at 25°C, with a frequency range from 1000 KHz to 1 Hz and a voltage of 5 mV. The calculated room temperature ionic conductivity of 1Li2O-AlCl3 is 0.055 mS / cm, as shown in Figure 3 . Example 3
[0037] A method for preparing an AlCl3-based chloride solid-state electrolyte, comprising the following steps: Step S1, weighing Li2O and AlCl3 raw materials according to the stoichiometric ratio of the chemical formula under an inert gas protective atmosphere; specifically, 0.896 g of Li2O and 2.667 g of AlCl3 are weighed, and it can be calculated that the sample synthesized in this example is 1.5Li2O-AlCl3.
[0038] Step S2, the weighed Li2O and AlCl3 raw materials in step S1 are placed in a sealed ball mill jar together with the ball mill balls to perform a ball milling reaction to obtain a ball milling product; specifically, 10 zirconia large balls and 30 small balls are taken to form the ball mill balls, wherein the diameter of the large balls is 10 mm, the diameter of the small balls is 3 mm, and the ball-to-material ratio (total mass ratio of balls to raw materials) is 11:1. The above ball milling raw materials and ball mill balls are added to the ball mill jar and sealed, and ball milling is performed at a speed of 600 rpm for 300 min. During the ball milling process, the ball mill is stopped and cooled for 5 min every 10 min of continuous ball milling. The ball milling product is obtained.
[0039] Step S3, the ball milling product in step S2 is tabletted under an inert gas protective atmosphere to obtain an AlCl3-based chloride solid-state electrolyte; specifically, the ball milling product in step S2 is taken out under an argon protective atmosphere, and part of the powder is tested for XRD. The AlCl3-based chloride solid-state electrolyte is directly tabletted in a tablet press under a pressure of 600 MPa in an argon protective atmosphere, and the room temperature impedance is tested.
[0040] As shown in Figure 1 , the XRD data of 1.5Li2O-AlCl3 indicates that the 1.5Li2O-AlCl3 sample is mainly amorphous, accompanied by a certain amount of Li2O phase. Figure 2 The room temperature impedance spectrum of 1.5Li2O-AlCl3 was measured using an electrochemical workstation model (SP-50e, Bio-Logic) at 25°C, with a frequency range of 1000 KHz to 1 Hz and a voltage of 5 mV. The calculated room temperature ionic conductivity of 1.5Li2O-AlCl3 is 0.088 mS / cm, as shown in Figure 3 . Example 4
[0041] A method for preparing an AlCl3-based chloride solid-state electrolyte, comprising the following steps: Step S1, weighing Li2O and AlCl3 raw materials according to the stoichiometric ratio of the chemical formula under an inert gas protective atmosphere; specifically, 1.196 g of Li2O and 2.667 g of AlCl3 are weighed, and it can be calculated that the sample synthesized in this example is 2Li2O-AlCl3.
[0042] Step S2, the weighed Li2O and AlCl3 raw materials in step S1 are placed in a sealed ball mill jar together with the ball mill balls to perform a ball milling reaction to obtain a ball milling product; specifically, 10 zirconia large balls and 30 small balls are used as ball mill balls, wherein the large balls have a diameter of 10 mm, the small balls have a diameter of 3 mm, and the ball-to-raw material ratio (total mass ratio of balls to raw materials) is 10:1. The ball milling raw materials and ball mill balls are added to the ball mill jar and sealed, and ball milling is performed at a speed of 600 rpm for 300 min. During the ball milling process, the ball mill is stopped and cooled for 5 min every 10 min of continuous ball milling. The ball milling product is obtained.
[0043] Step S3, the ball milling product in step S2 is tableted under an inert gas protective atmosphere to obtain an AlCl3-based chloride solid-state electrolyte; specifically, the ball milling product in step S2 is taken out under an argon protective atmosphere, and part of the powder is tested for XRD. The AlCl3-based chloride solid-state electrolyte is directly tableted in a tablet press under an argon protective atmosphere at a pressure of 600 MPa, and the room temperature impedance is tested.
[0044] As shown in Figure 1 , the XRD data of 2Li2O-AlCl3 indicates that the 2Li2O-AlCl3 sample is in an amorphous phase, accompanied by a large amount of Li2O phase and a small amount of LiCl phase. Figure 2 The room temperature impedance spectrum of 2Li2O-AlCl3 was obtained using an electrochemical workstation model (SP-50e, Bio-Logic) at 25°C, with a frequency range of 1000 KHz to 1 Hz and a voltage of 5 mV. The calculated room temperature ionic conductivity of 2Li2O-AlCl3 was 0.24 mS / cm, as shown in Figure 3 .
[0045] Figure 4 The temperature-dependent impedance spectrum of 2Li2O-AlCl3 was obtained, which was used to calculate the ionic conductivity of 2Li2O-AlCl3 solid-state electrolyte at different temperatures, and the activation energy of 2Li2O-AlCl3 was calculated to be 0.36 eV, as shown in Figure 5 .
[0046] Taking Example 4 (2Li2O-AlCl3) as an example, the current market price of Li2O is 3600 yuan / kg, and the current market price of AlCl3 is 147.2 yuan / kg. The calculated raw material cost of 2Li2O-AlCl3 is 1219 yuan / kg, which is significantly lower than the cost of the prior art (the cost of ZrCl4-based solid-state electrolyte is 2564 yuan / kg). The raw materials selected in this experiment are all 99% pharmaceutical agents sold by Innochem. Example 5
[0047] A method for preparing an AlCl3-based chloride solid-state electrolyte, comprising the following steps: Step S1, under an inert gas protection atmosphere, Li2O and AlCl3 raw materials are weighed according to the stoichiometric ratio of the chemical formula; specifically, 1.495 g of Li2O and 2.667 g of AlCl3 are weighed, and it can be calculated that the sample synthesized in this embodiment is 2.5Li2O-AlCl3.
[0048] Step S2, the Li2O and AlCl3 raw materials weighed in step S1 are placed in a sealed ball mill pot together with the ball mill balls to perform a ball milling reaction, and a ball milling product is obtained; specifically, 10 large zirconia balls and 30 small zirconia balls are used as ball mill balls, wherein the diameter of the large balls is 10 mm, the diameter of the small balls is 3 mm, and the ball-to-raw material ratio (total mass ratio of balls to raw materials) is 9:1. The above ball milling raw materials and ball mill balls are added to the ball mill pot and sealed, and ball milling is performed at a speed of 600 rpm for 300 min. During the ball milling process, the ball mill stops cooling for 5 min every 10 min of continuous ball milling; the ball milling product is obtained.
[0049] Step S3, the ball milling product of step S2 is tabletted under an inert gas protection atmosphere to obtain an AlCl3-based chloride solid-state electrolyte; specifically, the ball milling product in step S2 is taken out under an argon protection atmosphere, and part of the powder is tested for XRD. Under an argon protection atmosphere, tabletting is directly performed in a tablet press at a pressure of 600 MPa to obtain an AlCl3-based chloride solid-state electrolyte, and the room temperature impedance is tested.
[0050] As shown in Figure 1 , the XRD data of 2.5Li2O-AlCl3 indicates that the 2.5Li2O-AlCl3 sample is an amorphous phase, accompanied by a large amount of Li2O and LiCl phases. Figure 2 The room temperature impedance spectrum of 2.5Li2O-AlCl3 was measured using an electrochemical workstation model (SP-50e, Bio-Logic) at 25°C, with a frequency range of 1000 KHz to 1 Hz and a voltage of 5 mV. The calculated room temperature ionic conductivity of 2.5Li2O-AlCl3 is 0.094 mS / cm, as shown in Figure 3 .
[0051] It should be understood that although the present specification is described in terms of various embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that those skilled in the art can understand.
[0052] The above detailed description is merely exemplary in nature and is not intended to limit the present application or the application and uses of it. Various changes to the details can be made in the application without departing from the spirit of the application, which is defined by the appended claims.
Claims
1. A chloride solid electrolyte based on AlCl3, characterized in that, Its general chemical formula is xLi2O-AlCl3, where x represents the molar ratio coefficient of Li2O and AlCl3. The general chemical formula xLi2O-AlCl3 represents a composite material formed by the composite reaction of x moles of Li2O and 1 mole of AlCl3, and 0.5≤x≤2.
5.
2. The chloride solid electrolyte based on AlCl3 according to claim 1, characterized in that, In xLi2O-AlCl3, the value of x is 2.
3. The chloride solid electrolyte based on AlCl3 according to claim 1 or 2, characterized in that, The room temperature ionic conductivity of the AlCl3-based chloride solid electrolyte is not less than 0.24 mS / cm.
4. A method for preparing an AlCl3-based chloride solid electrolyte according to any one of claims 1-3, characterized in that, Includes the following steps: Step S1: Under an inert gas protective atmosphere, weigh the Li2O and AlCl3 raw materials according to the stoichiometric ratio of the general chemical formula; Step S2: Place the weighed Li2O and AlCl3 raw materials from step S1 together with the ball milling balls into a sealed ball milling jar for ball milling reaction to obtain the ball milling product. Step S3: The ball milling product described in step S2 is pressed into tablets under an inert gas protective atmosphere to obtain an AlCl3-based chloride solid electrolyte.
5. The method for preparing AlCl3-based chloride solid electrolyte according to claim 4, characterized in that, In steps S1 and S3, the protective atmosphere is argon.
6. The method for preparing AlCl3-based chloride solid electrolyte according to claim 4, characterized in that, In step S2, the total mass ratio of the milling balls to the raw materials is (9~13):
1.
7. The method for preparing AlCl3-based chloride solid electrolyte according to claim 4, characterized in that, In step S2, the ball milling speed is 500~600 rpm, and the total ball milling time is 200~600 min; the ball milling is intermittent ball milling, specifically: after each continuous ball milling for 5~30 min, it is paused and cooled for 5~10 min.
8. The method for preparing AlCl3-based chloride solid electrolyte according to claim 7, characterized in that, In step S2, the ball milling rate is 600 rpm and the ball milling time is 300 min; after each 10 min of continuous ball milling, the process is paused and cooled for 5 min.
9. The method for preparing AlCl3-based chloride solid electrolyte according to claim 4, characterized in that, In step S3, the pressure for tableting is 500~700 MPa.
10. The method for preparing the AlCl3-based chloride solid electrolyte according to claim 9, characterized in that, In step S3, the pressure for tableting is 600 MPa.