Amorphous electrolyte and preparation method and application thereof

Abstract

The invention discloses an amorphous electrolyte. The amorphous structural general formula of the electrolyte is Li M N < m > X < n >, wherein M is one or more of Mg, Ca, Fe, Sr, Al, Zr, Hf, Sc, In, Ta, Nb, Y and La; wherein N is one or more of Ca, Zn, Cu, Sn, Zr, Hf, In, Ta, Nb, W, Al, La, Ce and Sm; wherein X is one or more of F, Cl, Br, I, N, O and S; wherein 0.5 < = a < = 12, 0.7 < = b < = 8, 0.1 < = m < = 5, and n > 0. The preparation method comprises the following steps: firstly, uniformly mixing a Li source, an M source and an N source which are weighed, and then synthesizing to obtain the amorphous electrolyte through high-energy ball milling. The amorphous electrolyte is applied to an all-solid-state lithium battery. The amorphous electrolyte has high ionic conductivity, the preparation method is simple, the amorphous electrolyte can be matched with a plurality of commercial positive electrode materials, and an all-solid-state battery assembled by using the halide solid electrolyte material has excellent electrochemical performance and has a commercial prospect.

Description

Technical Field

[0001] The present invention relates to the technical field of battery materials, and in particular to an amorphous electrolyte and a preparation method and application thereof. Background Art

[0002] With the rapid development of social economy and the rapid progress of science and technology, the limitations of traditional lithium-ion batteries have become increasingly prominent. On the one hand, commercial electrolytes have a series of safety hazards due to flammability and other issues. On the other hand, the rapid development of energy storage technology has put forward higher requirements for rechargeable lithium-ion batteries, including higher energy density, better safety and better charging performance. All-solid-state batteries have attracted much attention due to their higher energy density and better safety performance. As a key material in all-solid-state batteries, the electrolyte solid (SE) itself has a decisive role in the performance of all-solid-state batteries due to its own ion conduction channel and the stability of the anode and cathode interfaces.

[0003] In order to promote the practical application of electrolytes, it is necessary to develop SEs with high ionic conductivity and wide working voltage. Polymer solid electrolytes have the advantages of good flexibility, light weight, and easy processing, but due to their low ionic conductivity and high-voltage instability, they are difficult to meet practical needs; although the conductivity of sulfide solid electrolytes can reach 10 mS / cm, their electrochemical window is narrow, their compatibility with positive electrode materials is low, and they are very easy to decompose and produce H2S gas in a humid environment; the synthesis of oxide solid electrolytes requires ultra-high sintering temperatures, and their machinability is poor; based on the above problems, the practical application of oxide and sulfide solid electrolytes in the field of all-solid-state batteries is limited. Therefore, it is necessary to design an amorphous electrolyte and its preparation method and application. Summary of the invention

[0004] In order to overcome the defects in the prior art, an amorphous electrolyte and a preparation method and application thereof are provided.

[0005] The present invention is achieved through the following scheme:

[0006] An amorphous electrolyte, the amorphous electrolyte has a general structural formula of: Li a M b N m X n ;

[0007] Wherein M is one or more of Mg, Ca, Fe, Sr, Al, Zr, Hf, Sc, In, Ta, Nb, Y, and La;

[0008] Wherein N is one or more of Ca, Zn, Cu, Sn, Zr, Hf, In, Ta, Nb, W, Al, La, Ce, and Sm;

[0009] Wherein X is one or more of F, Cl, Br, I, N, O, and S;

[0010] Among them, 0.5≤a≤12, 0.7≤b≤8, 0.1≤m≤5, n>0.

[0011] A method for preparing an amorphous electrolyte comprises the following steps: firstly, weighed Li source, M source and N source are mixed evenly, and then the amorphous electrolyte is synthesized by high-energy ball milling.

[0012] The high-energy ball milling speed is 150rpm-650rpm, including but not limited to 150rpm, 200rpm, 250rpm, 300rpm, 350rpm, 400rpm, 450rpm, 500rpm, 550rpm, 600rpm, and 650rpm; the high-energy ball milling time is 10-65h, including but not limited to 10h, 15h, 20h, 30h, 45h, 60h, and 65h; the ball-to-material ratio of the high-energy ball milling is 1:10-80, including but not limited to 1:10, 1:20:, 1:40:, 1:60, and 1:80.

[0013] The Li source, M source and N source were weighed according to the molar ratio of the electrolyte chemical formula.

[0014] The Li source is one or more of lithium fluoride, lithium chloride, lithium bromide, lithium iodide, lithium oxide, lithium nitride, lithium sulfide, lithium nitrate, and lithium sulfate.

[0015] The M source is one or more of magnesium chloride, calcium chloride, ferric chloride, strontium chloride, aluminum chloride, zirconium chloride, hafnium chloride, scandium chloride, indium chloride, tantalum chloride, niobium chloride, yttrium chloride, and lanthanum chloride.

[0016] The N source is one or more of calcium oxide, zinc oxide, copper oxide, tin dioxide, zirconium dioxide, hafnium dioxide, indium trioxide, tantalum pentoxide, niobium pentoxide, tungsten trioxide, aluminum trioxide, lanthanum trioxide, cerium trioxide, and samarium trioxide; X is one or more of F, Cl, Br, I, N, O, and S.

[0017] The environmental atmosphere during the sample weighing and preparation process is an inert atmosphere, which includes an argon atmosphere.

[0018] An application of an amorphous electrolyte, wherein the amorphous electrolyte is applied to an all-solid-state lithium battery, and comprises one or more of a positive electrode, an electrolyte, an interface layer, a coating material, and a passivation layer.

[0019] The beneficial effects of the present invention are:

[0020] 1. The amorphous electrolyte of the present invention has high ionic conductivity, and its room temperature ionic conductivity is ≥1 mS / cm;

[0021] 2. The preparation method of the amorphous electrolyte of the present invention is simple and can match several commercial positive electrode materials (such as LiCoO2, NCM811, etc.). The all-solid-state battery assembled using the halide solid electrolyte material has excellent electrochemical properties and has commercial prospects. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with specific embodiments:

[0023] An amorphous electrolyte, the amorphous electrolyte has a general structural formula of: Li a M b N m X n ;

[0024] Wherein M is one or more of Mg, Ca, Fe, Sr, Al, Zr, Hf, Sc, In, Ta, Nb, Y, and La;

[0025] Wherein N is one or more of Ca, Zn, Cu, Sn, Zr, Hf, In, Ta, Nb, W, Al, La, Ce, and Sm;

[0026] Wherein X is one or more of F, Cl, Br, I, N, O, and S;

[0027] Among them, 0.5≤a≤12, 0.7≤b≤8, 0.1≤m≤5, n>0.

[0028] A method for preparing an amorphous electrolyte comprises the following steps: firstly, weighed Li source, M source and N source are mixed evenly, and then the amorphous electrolyte is synthesized by high-energy ball milling.

[0029] The high-energy ball milling speed is 150rpm-650rpm, including but not limited to 150rpm, 200rpm, 250rpm, 300rpm, 350rpm, 400rpm, 450rpm, 500rpm, 550rpm, 600rpm, and 650rpm; the high-energy ball milling time is 10-65h, including but not limited to 10h, 15h, 20h, 30h, 45h, 60h, and 65h; the ball-to-material ratio of the high-energy ball milling is 1:10-80, including but not limited to 1:10, 1:20:, 1:40:, 1:60, and 1:80.

[0030] The Li source, M source and N source were weighed according to the molar ratio of the electrolyte chemical formula.

[0031] The Li source is one or more of lithium fluoride, lithium chloride, lithium bromide, lithium iodide, lithium oxide, lithium nitride, lithium sulfide, lithium nitrate, and lithium sulfate.

[0032] The M source is one or more of magnesium chloride, calcium chloride, ferric chloride, strontium chloride, aluminum chloride, zirconium chloride, hafnium chloride, scandium chloride, indium chloride, tantalum chloride, niobium chloride, yttrium chloride, and lanthanum chloride.

[0033] The N source is one or more of calcium oxide, zinc oxide, copper oxide, tin dioxide, zirconium dioxide, hafnium dioxide, indium trioxide, tantalum pentoxide, niobium pentoxide, tungsten trioxide, aluminum trioxide, lanthanum trioxide, cerium trioxide, and samarium trioxide; X is one or more of F, Cl, Br, I, N, O, and S.

[0034] The environmental atmosphere during the sample weighing and preparation process is an inert atmosphere, which includes an argon atmosphere.

[0035] An application of an amorphous electrolyte, wherein the amorphous electrolyte is applied to an all-solid-state lithium battery, and comprises one or more of a positive electrode, an electrolyte, an interface layer, a coating material, and a passivation layer.

[0036] The present application is further described below according to specific embodiments:

[0037] Example 1

[0038] This embodiment provides a halide electrolyte, that is, an amorphous electrolyte of the present application (hereinafter the same), and the specific preparation method is as follows:

[0039] Weigh corresponding amounts of lithium oxide, tantalum chloride and lanthanum trioxide in a molar ratio of 1:1:0.1, and mix the raw materials evenly;

[0040] Then the sample was synthesized by high-energy ball milling, with a ball mill speed of 500 rpm, a ball milling time of 20 h, and a ball-to-material ratio of 1:40. The obtained sample was labeled 1-Li-Ta-La-O-Cl;

[0041] An all-solid-state lithium battery is assembled using LiCoO2 as the positive electrode, the prepared halide solid electrolyte as the electrolyte, LPSC as the protective layer, and Li-In alloy as the negative electrode.

[0042] Example 2

[0043] This embodiment provides a halide electrolyte, and the specific preparation method is as follows:

[0044] Weigh corresponding amounts of lithium oxide, tantalum chloride and lanthanum trioxide in a molar ratio of 1:1:0.2, and mix the raw materials evenly;

[0045] Then the sample was synthesized by high-energy ball milling, with a ball mill speed of 500 rpm, a ball milling time of 20 h, and a ball-to-material ratio of 1:40. The obtained sample was labeled 2-Li-Ta-La-O-Cl;

[0046] An all-solid-state lithium battery is assembled using LiCoO2 as the positive electrode, the prepared halide solid electrolyte as the electrolyte, LPSC as the protective layer, and Li-In alloy as the negative electrode.

[0047] Example 3

[0048] This embodiment provides a halide electrolyte, and the specific preparation method is as follows:

[0049] Weigh corresponding amounts of lithium oxide, tantalum chloride and aluminum oxide in a molar ratio of 1:1:0.1, and mix the raw materials evenly;

[0050] The sample was then synthesized by high-energy ball milling with a ball mill speed of 500 rpm, a ball milling time of 25 h, a ball-to-material ratio of 1:40, and the obtained sample was labeled 1-Li-Ta-Al-O-Cl.

[0051] An all-solid-state lithium battery is assembled using LiCoO2 as the positive electrode, the prepared halide solid electrolyte as the electrolyte, LPSC as the protective layer, and Li-In alloy as the negative electrode.

[0052] Example 4

[0053] This embodiment provides a halide electrolyte, and the specific preparation method is as follows:

[0054] Weigh corresponding amounts of lithium oxide, tantalum chloride and aluminum oxide in a molar ratio of 1:1:0.2, and mix the raw materials evenly;

[0055] The sample was then synthesized by high-energy ball milling with a ball mill speed of 500 rpm, a ball milling time of 25 h, a ball-to-material ratio of 1:40, and the obtained sample was labeled 2-Li-Ta-Al-O-Cl.

[0056] An all-solid-state lithium battery is assembled using LiCoO2 as the positive electrode, the prepared halide solid electrolyte as the electrolyte, LPSC as the protective layer, and Li-In alloy as the negative electrode.

[0057] The performance of the all-solid-state lithium battery obtained in Examples 1-4 was tested according to the following method, and the results are shown in Table 1:

[0058] 1. Ionic conductivity: Place 80mg-150mg electrolyte in a battery mold with a diameter of 10mm, apply a pressure of 300-500Mpa, and measure its impedance using an electrochemical workstation. The ionic conductivity calculation formula is: σ=L / (R·A), where L is the electrolyte thickness and A is the effective area (about 0.785cm 2 ), R is the impedance value.

[0059] 2. Electrochemical data: Calculate the capacity retention rate after 200 cycles.

[0060] Table 1 Performance test results

[0061] Sample No. Conductivity (mS / cm) Capacity retention rate (%) Example 1 2.5 86 Example 2 2.2 89 Example 3 2.4 85 Example 4 2.0 90

[0062] It can be seen from Table 1 that the halide electrolyte provided by the present invention can directly match a variety of commercial positive electrode materials (such as LiCoO2, NCM811, etc.), and the all-solid-state battery assembled using the halide solid electrolyte material has excellent electrochemical properties and has commercial prospects.

[0063] Although the technical solutions of the present invention have been described and listed in detail, it should be understood that it is obvious to those skilled in the art to make modifications to the above embodiments or adopt equivalent alternatives. These modifications or improvements made without departing from the spirit of the present invention are within the scope of protection required by the present invention.

Claims

1. An amorphous electrolyte, characterized in that: The general structural formula of the electrolyte amorphous is: Li a M b N m X n ; Wherein M is one or more of Mg, Ca, Fe, Sr, Al, Zr, Hf, Sc, In, Ta, Nb, Y, and La; Wherein N is one or more of Ca, Zn, Cu, Sn, Zr, Hf, In, Ta, Nb, W, Al, La, Ce, and Sm; Wherein X is one or more of F, Cl, Br, I, N, O, and S; Among them, 0.5≤a≤12, 0.7≤b≤8, 0.1≤m≤5, n>0.

2. A method for preparing the amorphous electrolyte as claimed in claim 1, characterized in that: The method comprises the following steps: firstly, weighed Li source, M source and N source are mixed evenly, and then an amorphous electrolyte is synthesized by high-energy ball milling.

3. The method for preparing an amorphous electrolyte according to claim 2, characterized in that: The high-energy ball milling speed is 150rpm-650rpm, including but not limited to 150rpm, 200rpm, 250rpm, 300rpm, 350rpm, 400rpm, 450rpm, 500rpm, 550rpm, 600rpm, and 650rpm; the high-energy ball milling time is 10-65h, including but not limited to 10h, 15h, 20h, 30h, 45h, 60h, and 65h; the ball-to-material ratio of the high-energy ball milling is 1:10-80, including but not limited to 1:10, 1:20:, 1:40:, 1:60, and 1:

80.

4. The method for preparing an amorphous electrolyte according to claim 2, characterized in that: The Li source, M source and N source were weighed according to the molar ratio of the electrolyte chemical formula.

5. The method for preparing an amorphous electrolyte according to claim 4, characterized in that: The Li source is one or more of lithium fluoride, lithium chloride, lithium bromide, lithium iodide, lithium oxide, lithium nitride, lithium sulfide, lithium nitrate, and lithium sulfate.

6. The method for preparing an amorphous electrolyte according to claim 4, characterized in that: The M source is one or more of magnesium chloride, calcium chloride, ferric chloride, strontium chloride, aluminum chloride, zirconium chloride, hafnium chloride, scandium chloride, indium chloride, tantalum chloride, niobium chloride, yttrium chloride, and lanthanum chloride.

7. The method for preparing an amorphous electrolyte according to claim 4, characterized in that: The N source is one or more of calcium oxide, zinc oxide, copper oxide, tin dioxide, zirconium dioxide, hafnium dioxide, indium trioxide, tantalum pentoxide, niobium pentoxide, tungsten trioxide, aluminum trioxide, lanthanum trioxide, cerium trioxide, and samarium trioxide; X is one or more of F, Cl, Br, I, N, O, and S.

8. The method for preparing an amorphous electrolyte according to claim 2, characterized in that: The environmental atmosphere during the sample weighing and preparation process is an inert atmosphere, which includes an argon atmosphere.

9. An application of the amorphous electrolyte as claimed in claim 1, characterized in that: The amorphous electrolyte is applied to an all-solid-state lithium battery, and includes one or more of a positive electrode, an electrolyte, an interface layer, a coating material, and a passivation layer.