Lithium-ion conductor, lithium battery containing the same, and method for manufacturing a lithium-ion conductor

Abstract

リチウムイオン伝導体、これを含むリチウム電池及びリチウムイオン伝導体製造方法を提供する。【解決手段】リチウムイオン伝導体であって、下記化学式1で表される第1化合物;及び下記化学式2で表される第2化合物を含み、前記リチウムイオン伝導体のXRDスペクトルで回折角(2θ)23.8°~24.5°での第1ピークを有するリチウムイオン伝導体、及びこれを含む全固体電池が提供される:<化学式1>LixB4-yM13+yO12X1z<化学式2>LixB7O12X2z化学式1及び化学式2は、詳細な説明に開示されたところと同一である。

Claims

1. A lithium-ion conductor, The first compound represented by chemical formula 1, It contains a second compound represented by chemical formula 2, The lithium-ion conductor having a first peak at a diffraction angle (2θ) of 23.8° to 24.5° in its XRD spectrum: <Chemical formula 1> Li ｘ B ４－ｙ M1 ３＋ｙ O １２ X1 ｚ In the aforementioned chemical formula 1, 3.8 ≤ x ≤ 4.2, 0 ≤ y < 4 and 0.5 ≤ z ≤ 1.2, M1 is one or more elements belonging to groups 13 through 15 of the periodic table. X1 is one or more halogen elements, <Chemical formula 2> Li ｘ B ７ O １２ X2 ｚ In the aforementioned chemical formula 2, 3.8 ≤ x ≤ 4.2 and 0.5 ≤ z ≤ 1.2, X2 is one or more halogen elements.

2. The lithium ion conductor has a second peak, The lithium-ion conductor according to claim 1, wherein the diffraction angle of the second peak is smaller than the diffraction angle of the first peak.

3. The lithium ion conductor according to claim 2, wherein the ratio Ic / Ia of the peak intensity of the first peak to the peak intensity Ia of the second peak is 0.05 or more.

4. The lithium ion conductor according to claim 3, wherein the ratio Ic / Ia of the peak intensity of the first peak to the peak intensity Ia of the second peak is 0.1 or greater.

5. The lithium-ion conductor has a third peak at a diffraction angle (2θ) of 25.3 ± 0.5° in its XRD spectrum. The lithium ion conductor according to claim 1, wherein the ratio Ic / Ib, which is the ratio of the peak intensity Ic of the first peak to the peak intensity Ib of the third peak, is greater than 0.

1.

6. The lithium ion conductor according to claim 1, wherein the first compound has an a-axis lattice parameter of 12.945 Å or greater.

7. The third compound further comprises a third compound having a cubic structure, The third compound has different a-axis lattice parameters from the first compound, The lithium-ion conductor according to claim 1, wherein the a-axis lattice parameter of the third compound is 12.580 Å to 12.940 Å.

8. The aforementioned third compound is distinguished from the aforementioned first compound, The lithium ion conductor according to claim 7, wherein the third compound comprises lithium, boron, one or more elements (M1) belonging to groups 13 to 15 of the periodic table, oxygen, and halogen.

9. The content of one or more elements belonging to Groups 13 to 15 of the periodic table of the third compound (C Ｍ１ Boron content (C) relative to ) Ｂ The content ratio of ) is the content of one or more elements belonging to Groups 13 to 15 of the periodic table of the first compound (C Ｍ１ Boron content (C) relative to ) Ｂ A lithium ion conductor according to claim 7, wherein the content ratio is greater than that of ).

10. The lithium-ion conductor according to claim 1, wherein the first compound is represented by the following chemical formula 4: <Chemical formula 4> Li ｘ B ４－ｙ 72 ３＋ｙ 9 １２ 84 ｚ In the aforementioned chemical formula 4, 3.9 ≤ x ≤ 4.1, 0 ≤ y < 3, and 0.7 ≤ z ≤ 1.

1. M2 is Al, Ga, Si, Ge, P, or a combination of these. X4 is F, Cl, Br, I, or a combination of these.

11. The lithium-ion conductor according to claim 1, wherein the second compound is represented by the following chemical formula 5: <Chemical formula 5> Li ｘ B ７ O １２ 55 ｚ In the aforementioned chemical formula 5, 3.9 ≤ x ≤ 4.1 and 0.7 ≤ z ≤ 1.1, X5 is F, Cl, Br, I, or a combination of these.

12. The lithium ion conductor according to claim 1, further comprising an amorphous phase, a glass phase, or a combination thereof.

13. The ionic conductivity of the aforementioned lithium-ion conductor at 20°C and 1 atm is 3.7 × 10⁻⁶. －６ A lithium ion conductor according to claim 1, wherein the S / cm is 1 or higher.

14. The lithium-ion conductor according to claim 1, wherein the water absorption rate, which corresponds to the mass increase rate due to absorbed water after being left for 7 days at a relative humidity of 70%, is 30% or less.

15. Positive electrode; negative electrode; and The positive electrode includes a solid electrolyte layer disposed between the positive and negative electrodes, A lithium battery in which one or more of the positive electrode, negative electrode, and solid electrolyte layer include a lithium ion conductor according to any one of claims 1 to 14.

16. A method for manufacturing a lithium ion conductor according to any one of claims 1 to 14, The steps include preparing a precursor glass containing lithium, boron, M1 element, and halogen element, The steps include preparing an intermediate by annealing the aforementioned precursor glass, A method for producing a lithium-ion conductor, comprising the step of pressurizing and heat-treating the aforementioned intermediate to produce a lithium-ion conductor containing a crystalline phase.

17. The lithium-ion conductor manufacturing method according to claim 16, wherein the step of annealing the precursor glass is carried out at a temperature of 200 to 650°C.

18. The lithium-ion conductor manufacturing method according to claim 16, wherein the step of pressurized heat treatment is carried out at a temperature of 200 to 700°C under a pressure of 50 MPa to 500 MPa.

19. The step of preparing the precursor glass is as follows: Li ２ O, B ２ O ３ Al ２ O ３ , and the step of melting the mixture containing LiCl, A method for producing a lithium-ion conductor according to claim 16, comprising the step of cooling a molten material to form a precursor glass containing an amorphous phase or a glassy phase.

20. The method for producing a lithium ion conductor according to claim 19, wherein the mixture comprises 2 to 4 molar equivalents of lithium precursor, 3 to 5 molar equivalents of boron precursor, and 2 to 4 molar equivalents of M1 element precursor per molar equivalent of halogen precursor.

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