All solid-state secondary battery, inorganic solid electrolyte particles, solid electrolyte composition, electrode sheet for battery, and method for manufacturing all solid-state secondary battery

Patent metadata

Field	Value
Publication number	US-2017125842-A1
Application number	US-201715403471-A
Country	US
Kind code	A1
Filing date	Jan 11, 2017
Priority date	Jul 31, 2014
Publication date	May 4, 2017
Grant date	—

Abstract

Provided are an all solid-state secondary battery capable of exhibiting an improved ion-conducting property regardless of troublesome manufacturing steps or special materials, inorganic solid electrolyte particles, a solid electrolyte composition, an electrode sheet for a battery, and a method for manufacturing an all solid-state secondary battery.
An all solid-state secondary battery comprising: a positive electrode active material layer; a negative electrode active material layer; and an inorganic solid electrolyte layer between the positive and negative electrode active material layers, in which inorganic solid electrolyte particles satisfying all of the following data A are included in at least any layer of the positive electrode active material layer, the negative electrode active material layer, or the inorganic solid electrolyte layer:
<data A>
a boundary length of a projected particle of the inorganic solid electrolyte particle is represented by L; a cross-sectional area of the projected particle of the inorganic solid electrolyte particle is represented by A; an unevenness coefficient FU represented by Expression (1) below is in a range of 0.85 or more and 1 or less;

FU =4π A/L 2   (1).

First claim

What is claimed is:

1 . An all solid-state secondary battery comprising:
a positive electrode active material layer, a negative electrode active material layer; and an inorganic solid electrolyte layer between the positive and negative electrode active material layers, wherein inorganic solid electrolyte particles satisfying all of the following data A are included in at least any layer of the positive electrode active material layer, the negative electrode active material layer, or the inorganic solid electrolyte layer: <data A>
a boundary length of a projected particle of the inorganic solid electrolyte particle is represented by L;
a cross-sectional area of the projected particle of the inorganic solid electrolyte particle is represented by A;
an unevenness coefficient FU represented by Expression (1) below is in a range of 0.85 or more and 1 or less;
FU= 4π A/L 2   (1).

2 . The all solid-state secondary battery according to claim 1 ,
wherein an average particle diameter of the inorganic solid electrolyte particles is 1 μm or more and 10 m or less.

3 . The all solid-state secondary battery according to claim 1 ,
wherein D90 of the inorganic solid electrolyte particles is 2 μm or more and 20 μm or less.

4 . The all solid-state secondary battery according to claim 1 ,
wherein a flatness ratio that is evaluated using Feret's diameter of the inorganic solid electrolyte particles is 1.2 or higher and 1.76 or lower.

5 . The all solid-state secondary battery according to claim 1 ,
wherein thicknesses of the positive electrode active material layer, the negative electrode active material layer, and the inorganic solid electrolyte layer are respectively 1 μm or more and 1,000 μm or less.

6 . The all solid-state secondary battery according to claim 1 ,
wherein at least one layer of the positive electrode active material layer, the negative electrode active material layer, or the inorganic solid electrolyte layer includes a binder.

7 . The all solid-state secondary battery according to claim 1 ,
wherein the inorganic solid electrolyte particles are oxide-based inorganic solid electrolyte particles.

8 . The all solid-state secondary battery according to claim 7 ,
wherein the oxide-based inorganic solid electrolyte particles are selected from compounds of the following formulae: Li xa La ya TiO 3
xa=0.3 to 0.7, ya=0.3 to 0.7
Li 7 La 3 Zr 2 O 12 Li 3.5 Zn 0.25 GeO 4 LiTi 2 P 3 O 12 Li 1+xb+yb (Al, Ga) xb (Ti, Ge) 2−xb Si yb P 3−yb O 12
0≦xb≦1, 0≦yb≦1
Li 3 PO 4 LiPON LiPOD
D is at least one selected from Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Ag, Ta, W, Pt, or Au
LiAON
A is at least one selected from Si, B, Ge, Al, C, or Ga.

9 . The all solid-state secondary battery according to claim 1 ,
wherein the inorganic solid electrolyte particles are sulfide-based inorganic solid electrolyte particles.

10 . The all solid-state secondary battery according to claim 1 ,
wherein, when the inorganic solid electrolyte particles are prepared by means of stirring and crushing in a crushing medium including crushing particles in a mixing tank in a crusher, an average particle diameter of the crushing particles is set to 100 times or more and 1,500 times or less the average particle diameter of target inorganic solid electrolyte particles, and a filling percentage of the crushing particles in the mixing tank is set to be higher than 60% and 74% or lower according to a definition of Expression (2) below:
filling percentage α=Σ Z/V 0 ×100  (2)

V 0 : an inner volume of the mixing tank ΣZ: a sum of volumes of the crushing particles filling the mixing tank.

11 . The all solid-state secondary battery according to claim 10 ,
wherein the crushing particles include at least one material selected from agate, alumina, zirconia, stainless steel, chromium steel, tungsten carbide, or silicon nitride.

12 . A method for manufacturing inorganic solid electrolyte particles, comprising:
a step of preparing a raw material of the inorganic solid electrolyte particles; a step of feeding the raw material of the inorganic solid electrolyte particles, crushing particles, and a crushing medium into a mixing tank of a crusher; and a step of stirring the raw material of the inorganic solid electrolyte particles, the crushing particles, and the crushing medium in the mixing tank, wherein a filling percentage of the crushing particles in the mixing tank is set to be higher than 60% and 74% or lower according to a definition of Expression (2) below:
filling percentage α=Σ Z/V 0 ×100  (2)

V 0 : an inner volume of the mixing tank ΣZ: a sum of volumes of the crushing particles filling the mixing tank.

13 . The method for manufacturing inorganic solid electrolyte particles according to claim 12 ,
wherein an average particle diameter of the crushing particles is set to 100 times or more and 1,500 times or less the average particle diameter of target inorganic solid electrolyte particles.

14 . The all solid-state secondary battery according to claim 9 ,
wherein, when the sulfide-based inorganic solid electrolyte particles are prepared by means of stirring and crushing in a crushing medium including crushing particles in a mixing tank in a crusher, an average particle diameter of the crushing particles is set to 1,000 times or more and 10,000 times or less the average particle diameter of target inorganic solid electrolyte particles, and a density of the crushing particles is set to 0.9 g/cm 3 or more and 2.4 g/cm 3 or less.

15 . The all solid-state secondary battery according to claim 14 ,
wherein the crushing particles include at least one selected from thermosetting plastic particles, thermoplastic plastic particles, or rubber particles.

16 . A method for manufacturing inorganic solid electrolyte particles, comprising:
a step of preparing a sulfide-based electrolyte as a raw material of the inorganic solid electrolyte particles; a step of feeding the raw material of the inorganic solid electrolyte particles, crushing particles, and a crushing medium into a mixing tank of a crusher; and a step of stirring the raw material of the inorganic solid electrolyte particles, the crushing particles, and the crushing medium in the mixing tank, wherein a density of the crushing particles is set to 0.9 g/cm 3 or more and 2.4 g/cm 3 or less.

17 . The method for manufacturing inorganic solid electrolyte particles according to claim 16 ,
wherein an average particle diameter of the crushing particles is set to 1,000 times or more and 10,000 times or less the average particle diameter of target inorganic solid electrolyte particles.

18 . A method for manufacturing a solid electrolyte composition, comprising:
preparing a composition of inorganic solid electrolyte particles which is used for all solid-state secondary batteries using the method for manufacturing inorganic solid electrolyte particles according to claim 12 .

19 . A method for manufacturing an electrode sheet for a battery, comprising:
a step of imparting a solid electrolyte composition obtained using the manufacturing method according to claim 18 onto a metal foil.

20 . A method for manufacturing an all solid-state secondary battery, comprising:
manufacturing the all solid-state secondary battery using the method for manufacturing an electrode sheet for a battery according to claim 19 .

Assignees

• Fujifilm Corp

Inventors

• Meguro Katsuhiko
• Mochizuki Hiroaki
• Makino Masaomi
• Mimura Tomonori

Classifications

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M10/0562 Primary

  Solid materials · CPC title

• H01M10/0585

  of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators · CPC title

• H01M2300/0071

  Oxides · CPC title

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title