Solid electrolyte and lithium battery including the same

Patent metadata

Field	Value
Publication number	US-2017187066-A1
Application number	US-201615354614-A
Country	US
Kind code	A1
Filing date	Nov 17, 2016
Priority date	Dec 25, 2015
Publication date	Jun 29, 2017
Grant date	—

Abstract

A solid electrolyte for an all-solid secondary battery, the solid electrolyte including: Li, S, P, an M1 element, and an M2 element, wherein the M1 element is at least one element selected from Na, K, Rb, Sc, Fr, and the M2 element is at least one element selected from F, Cl, Br, I, molar amounts of lithium and the M1 element satisfy 0<M1/(Li+M1)≦0.07, and the solid electrolyte has peaks at positions of 15.42°±0.50° 2θ, 17.87° degrees±0.50° degrees 2θ, 25.48° degrees±0.50° degrees 2θ, 30.01° degrees±0.50° 2θ, and 31.38°±0.50° 2θ when analyzed by X-ray diffraction using CuKα radiation.

First claim

What is claimed is:

1 . A solid electrolyte for an all-solid secondary battery, the solid electrolyte comprising:
Li, S, P, an M1 element, and an M2 element, wherein the M1 element is at least one element selected from Na, K, Rb, Cs, Fr, the M2 element is at least one element selected from F, Cl, Br, I, molar amounts of Li and the M1 element satisfy 0<M1/(Li+M1)≦0.07, and the solid electrolyte has peaks at positions of 15.42°±0.50° 2θ, 17.87°±0.50° 2θ, 25.48°±0.50° 2θ, 30.01°±0.50° 2θ, and 31.38°±0.50° 2 θ when analyzed by X-ray diffraction using CuKα radiation.

2 . The solid electrolyte of claim 1 , wherein the M1 element is at least one element selected from Na and K.

3 . The solid electrolyte of claim 1 , wherein the M1 element is Na.

4 . The solid electrolyte of claim 1 , wherein the M2 element is Cl.

5 . The solid electrolyte of claim 1 , wherein the solid electrolyte has an Argyrodite structure.

6 . The solid electrolyte of claim 1 , wherein the solid electrolyte has a first peak first at a position of 30.01°±0.50° 2 θ and a second peak at a position of 33.65°±0.50° 2 θ when analyzed by X-ray diffraction using CuKα radiation, and
wherein a ratio of an intensity of the second to an intensity of the first peak is less than about 0.1.

7 . The solid electrolyte of claim 1 represented by Formula 1:
(Li 1-x M1 x ) 7-y PS 6-y M2 y   Formula 1

wherein, in Formula 1,
x and y satisfy 0<x≦0.07 and 0≦y≦2.

8 . The solid electrolyte of claim 7 , wherein the M1 element is Na.

9 . The solid electrolyte of claim 7 , wherein the M2 element is Cl.

10 . The solid electrolyte of claim 7 comprising (Li 5.6925 Na 0.0575 )PS 4.75 Cl 1.25 .

11 . A secondary battery comprising:
a cathode comprising a cathode active material; an anode comprising an anode active material; and a solid electrolyte layer comprising the solid electrolyte of claim 1 .

12 . The secondary battery of claim 11 , wherein the cathode active material comprises at least one selected from a lithium cobalt oxide, a lithium nickel oxide, a lithium nickel cobalt oxide, a lithium nickel cobalt aluminum oxide, a lithium nickel cobalt manganese oxide, a lithium manganese oxide, a lithium iron phosphate, a nickel sulfide, a copper sulfide, sulfur, an iron oxide, a vanadium oxide.

13 . The secondary battery of claim 12 , wherein the cathode active material further comprises the solid electrolyte of claim 1 and carbon nanofibers.

14 . The secondary battery of claim 11 , wherein the anode active material comprises at least one selected from a carbon active material, a metal active material, an oxide active material.

15 . The secondary battery of claim 11 , wherein an average particle diameter of the solid electrolyte layer is in a range of about 1 micrometer to about 10 micrometers.

16 . The secondary battery of claim 11 , wherein a thickness of the solid electrolyte layer is in a range of about 10 micrometers to about 200 micrometers.

17 . The secondary battery of claim 11 , wherein the secondary battery is an all-solid secondary battery.

18 . A method of preparing the solid electrolyte of claim 1 , the method comprising:
mechanically milling a mixture comprising Li 2 S, P 2 S 5 , and M1 2 S and LiM2, or M1M2 to obtain a glass; and heat-treating the glass at a glass transition temperature or greater to convert the glass into and ion conductive glass ceramic and obtain the solid electrolyte.

19 . The method of claim 18 , wherein the M1 element is Na.

20 . The method of claim 18 , wherein the M2 element is Cl.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Tsujimura Tomoyuki
• Suzuki Naoki
• Aihara Yuichi

Classifications

• H01M10/052

  Li-accumulators · CPC title

• H01M4/62

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

• H01M2300/0068

  inorganic · CPC title

• H01M10/0562 Primary

  Solid materials · CPC title

• H01M4/625

  Carbon or graphite · CPC title