All-solid-state secondary battery with solid electrolyte layer containing particulate precipitate of an olivine-type crystal structure

Patent metadata

Field	Value
Publication number	US-9865899-B2
Application number	US-201514971678-A
Country	US
Kind code	B2
Filing date	Dec 16, 2015
Priority date	Jun 28, 2013
Publication date	Jan 9, 2018
Grant date	Jan 9, 2018

Abstract

An all-solid-state secondary battery, including: a solid electrolyte layer; a positive electrode layer including a positive electrode active material layer and a first current collector layer; a negative electrode layer including a second current collector layer, the positive electrode layer and the negative electrode layer sandwiching the solid electrolyte layer; and external electrodes connected respectively to the first current collector layer and the second current collector layer, wherein the positive electrode active material layer is formed of an olivine-type active material, wherein the solid electrolyte layer is formed of a phosphate having a NASICON-type structure, and wherein the solid electrolyte layer contains particulate precipitate having an olivine-type crystal structure that includes a same element as an element forming the positive electrode active material layer.

First claim

What is claimed is:

1. An all-solid-state secondary battery, comprising:
a solid electrolyte layer;
a positive electrode layer including a positive electrode active material layer and a first current collector layer;
a negative electrode layer including a second current collector layer, the positive electrode layer and the negative electrode layer sandwiching the solid electrolyte layer; and
external electrodes connected respectively to the first current collector layer and the second current collector layer,
wherein the positive electrode active material layer is formed of an olivine-type active material that is LiMPO 4 , where M is a transition metal,
wherein the solid electrolyte layer is formed of a phosphate having a NASICON-type structure, and
wherein the solid electrolyte layer contains particulate precipitate having an olivine-type crystal structure that that is LiMPO 4 , where M is said transition metal, and an amount of said transition metal M in the solid electrolyte layer being within a range of 0.05 moles and 0.40 moles for each mole of said phosphate having the NASICON-type structure in the solid electrolyte layer.

2. The all-solid-state secondary battery according to claim 1 , wherein M is at least one of manganese (Mn), cobalt (Co), and nickel (Ni).

3. The all-solid-state secondary battery according to claim 1 , wherein the phosphate in the solid electrolyte layer has an AB 2 (PO 4 ) 3 skeleton, where A is lithium (Li), and B is at least one of titanium (Ti), germanium (Ge) and zirconium (Zr).

4. The all-solid-state secondary battery according to claim 3 , wherein the phosphate in the solid electrolyte layer having the AB 2 (PO 4 ) 3 skeleton is LiTi 2 (PO 4 ) 3 .

5. The all-solid-state secondary battery according to claim 1 , wherein the phosphate in the solid electrolyte layer is expressed as:
Li 1+x+z D x (E y Ti 1−y ) 2−x (SiO 4 ) z (PO 4 ) 3−z ,
where 0≦x≦0.8, 0≦y≦1, 0≦z≦0.5, D is at least one element of trivalent aluminum (Al) and gallium (Ga), and E is at least one element of quadrivalent germanium (Ge) and zirconium (Zr).

6. The all-solid-state secondary battery according to claim 1 , wherein a ratio of an area of the solid electrolyte layer occupied by the particulate precipitate is 0.3% to 16% in a cross section taken through a center of the solid electrolyte layer and following a plane orthogonal to an interface between the solid electrolyte layer and the positive electrode active material layer.

7. The all-solid-state secondary battery according to claim 1 , wherein a particle size of the particulate precipitate is less than or equal to 10 μm.

8. The all-solid-state secondary battery according to claim 1 , wherein the amount of said transition metal M in the solid electrolyte layer is within a range of 0.10 moles and 0.30 moles for each mole of said phosphate having the NASICON-type structure in the solid electrolyte layer.

Assignees

• Taiyo Yuden Kk

Inventors

• Ito Daigo
• Mochigi Masaki
• Tomita Masataka
• Suzuki Toshimasa

Classifications

• H01M2300/0068

  inorganic · CPC title

• H01M4/136

  Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy · CPC title

• H01M2004/029

  Bipolar electrodes · CPC title

• H01M4/5825

  Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines · CPC title

• H01M4/1397

  of electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy · CPC title