Solid electrolyte, lithium battery, battery pack, and vehicle

• US 10,707,523 B2
• Filed: 03/10/2017
• Issued: 07/07/2020
• Est. Priority Date: 09/20/2016
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Harada, Yasuhiro, Kusama, Tomoe, Takami, Norio, Yoshima, Kazuomi
• Primary Examiner(s): Ohara, Brian R
• Application Number:
  US15/455,346
• Publication Number:
  US 20180083314A1
• Time in Patent Office: 1,215 Days
• CPC Class Codes: C01B 25/45 containing plural metal, or metal and ammonium
• CPC Class Codes: C01P 2002/76 by a space-group or by other symmetry indications
• CPC Class Codes: C01P 2002/77 by unit-cell parameters, atom positions or structure diagrams
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/0562 Solid materials
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H01M 2300/0068 inorganic
• CPC Class Codes: H01M 2300/0091 in the form of mixtures
• CPC Class Codes: H01M 4/485 of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy H01M4/505, H01M4/525 take precedence
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 20/133 Renewable energy sources, e.g. sunlight
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries

Abstract

According to one embodiment, there is provided a solid electrolyte including an oxide represented by General Formula Li_1+2xM1_2−x(Ca_1−yM2_y)_x(PO₄)₃. In the General Formula above, M1 is at least one selected from the group consisting of Zr and Hf. M2 is at least one selected from the group consisting of Sr and Ba. x satisfies 0<x<2. y satisfies 0<y≤1.

Claims

1. A solid electrolyte comprising:

an oxide of formula Li_1+2x M1<sub>2−

x</sub>(Ca<sub>1−

y</sub> M2_y)_x(PO₄)₃,

wherein M1 is at least one selected from the group consisting of Zr and Hf, M2 is at least one selected from the group consisting of Sr and Ba, x satisfies 0.1≤

x≤

0.5, and y satisfies 0.05≤

y≤

1,

wherein the oxide comprises a crystal structure of a rhombohedral structure, and lattice constants of the crystal structure satisfy 8.85 Å

≤

a≤

8.89 Å and

22.13 Å

≤

c≤

22.21 Å

.

2. A lithium battery comprising:

a positive electrode layer capable of having lithium ions inserted and extracted;

a negative electrode layer capable of having lithium ions inserted and extracted; and

a Li conductive layer capable of conducting lithium ions,

wherein at least one of the positive electrode layer, the negative electrode layer, and the Li conductive layer comprises the solid electrolyte according to claim 1.

3. The lithium battery according to claim 2, wherein the positive electrode layer comprises a positive electrode active material particle and a polymer material layer, the polymer material layer covering at least a portion of a surface of the positive electrode active material particle and comprising the solid electrolyte.

4. The lithium battery according to claim 2, wherein at least one of the positive electrode layer, the negative electrode layer, and the Li conductive layer comprises a composite electrolyte, the composite electrolyte comprising the solid electrolyte and an organic electrolyte, a weight ratio of the organic electrolyte in the composite electrolyte being from 0.1% to 20%.

5. The lithium battery according to claim 2, wherein the Li conductive layer is interposed between the positive electrode layer and the negative electrode layer.

6. The lithium battery according to claim 2, further comprising plural stacks and a current collector, each of the plural stacks comprising the positive electrode layer, the Li conductive layer, and the negative electrode layer sequentially stacked in this order, wherein the lithium battery comprises a bipolar electrode structure in which the current collector is arranged between the positive electrode layer of one of the stacks and the negative electrode layer of another of the stacks.

7. The lithium battery according to claim 2, wherein the negative electrode layer comprises a negative electrode active material comprising a niobium-titanium composite oxide represented by Li_aTiM_bNb_2±

β

O<sub>7±

σ</sub>

, where 0<

a<

5, 0<

b<

0.3, 0<

β

<

0.3, 0<

σ

<

0.3, and M is at least one selected from the group consisting of Fe, V, Mo, and Ta.

8. The lithium battery according to claim 2, wherein the negative electrode layer comprises a negative electrode active material comprising a titanium composite oxide of formula Li_2+a M(I)₂₋

bTi<sub>6−

c</sub> M(II)_dO_14+σ

, where M(I) is Na or includes Na and at least one selected from the group consisting of Sr, Ba, Ca, Mg, Cs, and K, M(II) is at least one selected from the group consisting of Zr, Sn, V, Nb, Ta, Mo, W, Fe, Co, Mn, and Al, a satisfies 0≤

a≤

6, b satisfies 0≤

b<

2, c satisfies 0<

c<

6, d satisfies 0≤

d<

6, and σ

satisfies-0.5≤

σ

≤

0.5.

9. A battery pack comprising the lithium battery according to claim 2.

10. The battery pack according to claim 9, further comprising:

an external power distribution terminal; and

a protective circuit.

11. The battery pack according to claim 9, comprising a plurality of the lithium batteries, the lithium batteries being electrically connected in series, in parallel, or in a combination of in series and in parallel.

12. A vehicle comprising the battery pack according to claim 9.

13. The vehicle according to claim 12, wherein the battery pack is configured to recover a regenerative energy of power of the vehicle.

14. The solid electrolyte according to claim 1, which has a lithium ion conductivity at −

10°

C. of 1.8×

10<sup>−

7</sup> S/cm or more.