All-solid secondary battery and method of preparing the same

Patent metadata

Field	Value
Publication number	US-2021083252-A1
Application number	US-202017108139-A
Country	US
Kind code	A1
Filing date	Dec 1, 2020
Priority date	May 30, 2017
Publication date	Mar 18, 2021
Grant date	—

Abstract

An all-solid secondary battery including: a cathode including a cathode active material layer; an anode including an anode active material layer; and a solid electrolyte layer including a sulfide solid electrolyte between the cathode active material layer and the anode active material layer, wherein an arithmetic mean roughness (Ra) of an interface between the cathode active material layer and the solid electrolyte layer is about 1 micrometer or less, and a relative density of the solid electrolyte layer is about 80% or more.

First claim

What is claimed is:

1 . An all-solid secondary battery comprising:
a cathode comprising a cathode active material layer; an anode comprising
an anode current collector,
an anode active material layer on the anode current collector, wherein the anode active material layer comprises a carbon, and
a plated layer between the anode current collector and the anode active material layer, wherein the plated layer comprises lithium; and
a solid electrolyte layer between the cathode active material layer and the anode active material layer, wherein an arithmetic mean roughness of an interface between the cathode active material layer and the solid electrolyte layer is about 1 micrometer or less, and a relative density of the solid electrolyte layer is about 80% or more.

2 . The all-solid secondary battery of claim 1 , wherein the carbon is amorphous.

3 . The all-solid secondary battery of claim 1 , wherein the carbon comprises ketjen black, carbon black, oil furnace black, extra-conductive carbon black, acetylene black, lamp black, non-graphitizing carbon, coke, activated carbon or a combination thereof.

4 . The all-solid secondary battery of claim 1 , wherein the plated layer consists of lithium.

5 . The all-solid secondary battery of claim 1 , wherein the anode active material layer further comprises an active metal.

6 . The all-solid secondary battery of claim 5 , wherein the active metal comprises In, Al, Sn, Si, or a combination thereof.

7 . The all-solid secondary battery of claim 1 , wherein the relative density of the cathode active material layer is equal to or greater than about 60% and less than about 100%.

8 . The all-solid secondary battery of claim 1 , wherein a maximum height roughness of the interface between the cathode active material layer and the solid electrolyte layer is about 0.01 micrometers to about 4.5 micrometers.

9 . The all-solid secondary battery of claim 1 , wherein the cathode active material layer comprises a cathode active material and a solid electrolyte.

10 . The all-solid secondary battery of claim 1 , wherein the cathode active material layer comprises a lithium transition metal oxide with a layered rock-salt structure.

11 . The all-solid secondary battery of claim 1 , wherein the cathode active material layer comprises a compound represented by LiNi x Co y Al z O 2 , LiNi x′ Co y′ Mn z′ O 2 , or a combination thereof,
wherein x, y, and z satisfy 0<x<1, 0<y<1, 0<z<1, and x+y+z=1, and x′, y′, and z′ satisfy 0<x′<1, 0<y′<1, 0<z′<1, and x′+y′+z′=1.

12 . The all-solid secondary battery of claim 11 , wherein x satisfies 0.7<x<1, and x′ satisfies 0.7<x′<1.

13 . The all-solid secondary battery of claim 1 , wherein the cathode active material layer further comprises a binder.

14 . The all-solid secondary battery of claim 13 , wherein the binder comprises a vinylidene fluoride/hexafluoropropylene copolymer, polyvinylidene fluoride, polyacrylonitrile, polymethyl methacrylate, polytetrafluoroethylene, a styrene butadiene rubber polymer, or a combination thereof.

15 . The all-solid secondary battery of claim 1 , wherein a thickness of the solid electrolyte layer is about 5 micrometers to about 100 micrometers.

16 . The all-solid secondary battery of claim 1 , wherein the solid electrolyte layer comprises a sulfide solid electrolyte.

17 . The all-solid secondary battery of claim 16 , wherein the sulfide solid electrolyte comprises
Li 7−a PS 6−a X a wherein X is F, Cl, Br, I, or a combination thereof, 0≤a≤2, aLi 2 S-(1−a)P 2 S 5 wherein 0<a<1, aLi 2 S-bP 2 S 5 -cLiX wherein X is F, Cl, Br, I, or a combination thereof, 0<a<1, 0<b<1, 0<c<1, and a+b+c=1, aLi 2 S-bP 2 S 5 -cLi 2 O wherein 0<a<1, 0<b<1, 0<c<1, and a+b+c=1, aLi 2 S-bP 2 S 5 -cLi 2 O-dLiI wherein 0<a<1, 0<b<1, 0<c<1, 0<d<1 and a+b+c+d=1, aLi 2 S-(1−a)SiS 2 wherein 0<a<1, aLi 2 S-bSiS 2 -cLiI wherein 0<a<1, 0<b<1, 0<c<1, and a+b+c=1, aLi 2 S-bSiS 2 -cLiBr wherein 0<a<1, 0<b<1, 0<c<1, and a+b+c=1, aLi 2 S-bSiS 2 -cLiCl wherein 0<a<1, 0<b<1, 0<c<1, and a+b+c=1, aLi 2 S-bSiS 2 -cB 2 S 3 -dLiI wherein 0<a<1, 0<b<1, 0<c<1, 0<d<1 and a+b+c+d=1, aLi 2 S-bSiS 2 -cP 2 S 5 -dLiI wherein 0<a<1, 0<b<1, 0<c<1, 0<d<1 and a+b+c+d=1, aLi 2 S-(1−a)B 2 S 3 wherein 0<a<1, aLi 2 S-bP 2 S 5 -cZ m S n wherein m and n are each independently positive integers between 1 and 10, Z is Ge, Zn, or Ga, 0<a<1, 0<b<1, 0<c<1, and a+b+c=1, aLi 2 S-(1−a)GeS 2 wherein 0<a<1, aLi 2 S-bSiS 2 -cLi 3 PO 4 wherein 0<a<1, 0<b<1, 0<c<1, and a+b+c=1, or aLi 2 S-bSiS 2 -cLi P MO q wherein p and q are each independently positive integers between 1 and 10, 0<a<1, 0<b<1, 0<c<1, and a+b+c=1, and M is P, Si, Ge, B, Al, Ga, or In.

18 . The all-solid secondary battery of claim 1 , wherein the solid electrolyte layer comprises sulfur, phosphorus, and lithium.

19 . The all-solid secondary battery of claim 1 , further comprising a cathode current collector.

20 . The all-solid secondary battery of claim 1 , wherein a capacity retention of the all-solid secondary battery after 50 charge/discharge cycles is greater than about 75% and equal to or less than about 86%.

21 . The all-solid secondary battery of claim 1 , wherein a closed circuit voltage of the all-solid secondary battery is greater than about 2.4 volts to about 4.0 volts.

22 . A method of preparing the all-solid secondary battery of claim 1 , the method comprising:
providing a cathode comprising a cathode active material layer; disposing a solid electrolyte layer on the cathode; disposing an anode on the solid electrolyte layer, the anode comprising an anode current collector and an anode active material layer on the anode current collector, wherein the anode active material layer comprises a carbon; and providing a voltage between the cathode and the anode to form a plating layer between the anode active material layer and the anode current collector and prepare the all-solid secondary battery.

23 . The method of claim 22 , wherein the carbon is an amorphous carbon.

24 . The method of claim 23 , wherein the amorphous carbon is ketjen black, carbon black, oil furnace black, extra-conductive carbon black, acetylene black, lamp black, non-graphitizing carbon, coke, activated carbon, or a combination thereof.

25 . The method of claim 22 , wherein the plating layer consists of lithium.

26 . The method of claim 22 , wherein the anode active material layer further comprises an active metal.

27 . The method of claim 26 , wherein the active metal comprises In, Al, Sn, Si, or a combination thereof.

28 . The all-solid secondary battery of claim 1 , wherein the arithmetic mean roughness of the interface between the cathode active material layer and the solid electrolyte layer is about 0.01 micrometers to about 1 micrometer.

29 . The all-solid secondary battery of claim 1 , wherein the anode active material layer further comprises lithium.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Fujiki Satoshi
• Yamada Takanobu
• Shiratsuchi Tomoyuki
• Aihara Yuichi

Classifications

• H01M2300/008

  Halides · CPC title

• H01M2300/0071

  Oxides · CPC title

• H01M2300/0068

  inorganic · CPC title

• H01M50/431

  Inorganic material · CPC title

• H01M4/62

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