# US 2021/0242469 A1 · Cathode, lithium-air battery comprising the same, and method of preparing the cathode

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- Number: US 2021/0242469 A1
- Document ID: US20210242469A1
- Status: Published application
- Kind: A1
- Application number: 17/128,305
- Filed: 2020-12-21
- Published: 2021-08-05
- Earliest claimed: 2020-02-04
- Assignees: Samsung Electronics Co., Ltd.
- Applicants: Samsung Electronics Co., Ltd.
- Inventors: Hyunpyo LEE; Taeyoung KIM; Mokwon KIM; Wonsung CHOI
- Web page: https://patentgrep.com/patent/US20210242469A1

## CPC

- H01M 4/8605: {Porous electrodes}
- H01M 4/8621: {containing only metallic or ceramic material, e.g. made by sintering or sputtering}
- H01M 4/861: {with a gradient in the porosity}
- H01M 4/8828: {Coating with slurry or ink}
- H01M 4/8882: {Heat treatment, e.g. drying, baking}
- H01M 4/8896: {Pressing, rolling, calendering (membrane electrode assemblies H01M8/1004)}
- H01M 4/9016: {Oxides, hydroxides or oxygenated metallic salts}
- H01M 12/08: composed of a half-cell of a fuel-cell type and a half-cell of the secondary-cell type
- H01M 4/382: {Lithium (H01M4/405 takes precedence)}
- H01M 2004/8689: {Positive electrodes}
- Y02E 60/10: Energy storage using batteries
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A cathode configured to use oxygen as a cathode active material, the cathode including: a porous film, wherein the porous film includes a metal oxide, and wherein a surface of the porous film has root mean square (RMS) roughness (Rq) of about 0.01 micrometer to about 1 micrometer, and a porosity of the porous film is about 50 volume percent to about 99 volume percent, based on a total volume of the porous film.

## Claims

### Claim 1

A cathode configured to use oxygen as a cathode active material, the cathode comprising:
a porous film,
wherein the porous film comprises a metal oxide, and
wherein a surface of the porous film has a root mean square roughness of about 0.01 micrometer to about 1 micrometer, and a porosity of the porous film is about 50 volume percent to about 99 volume percent, based on a total volume of the porous film.

### Claim 2 (depends on 1)

The cathode of claim 1, wherein a mean roughness of the surface of the porous film is about 0.01 micrometer to about 1 micrometer.

### Claim 3 (depends on 1)

The cathode of claim 1, wherein a maximum roughness depth of the surface of the porous film is about 0.1 micrometer to about 10 micrometers.

### Claim 4 (depends on 1)

The cathode of claim 1, wherein the metal oxide is a lithium-containing metal oxide.

### Claim 5 (depends on 1)

The cathode of claim 1, wherein the porous film comprises a large-diameter pore, and a size of the large-diameter pore is about 1 micrometer or more.

### Claim 6 (depends on 5)

The cathode of claim 5, wherein an amount of the large-diameter pore is about 30 volume percent or more, based on a total volume of the porous film.

### Claim 7 (depends on 1)

The cathode of claim 1, wherein an amount of a lithium-containing metal oxide included in the porous film is about 50 weight percent or more, based on a total weight of the porous film.

### Claim 8 (depends on 4)

The cathode of claim 4, wherein an average particle diameter of the lithium-containing metal oxide is about 10 nanometers to about 500 nanometers.

### Claim 9 (depends on 4)

The cathode of claim 4, wherein the lithium-containing metal oxide is a crystalline lithium ion conductor, and wherein the lithium-containing metal oxide has an ionic conductivity of about 1.0×10−7 siemens per centimeter or more at 25° C.

### Claim 10 (depends on 4)

The cathode of claim 4, wherein the lithium-containing metal oxide is a crystalline electronic conductor, and wherein the lithium-containing metal oxide has an electronic conductivity of about 1.0×10−6 siemens per centimeter or more.

### Claim 11 (depends on 4)

The cathode of claim 4, wherein the lithium-containing metal oxide is a mixed conductor, and wherein the lithium-containing metal oxide has an electronic conductivity of about 1×10−6 siemens per centimeter or more at 25° C. and an ionic conductivity of about 1×10−7 siemens per centimeter or more at 25° C.

### Claim 12 (depends on 4)

The cathode of claim 4, wherein the lithium-containing metal oxide comprises at least one of a perovskite compound or a spinel compound.

### Claim 13 (depends on 4)

The cathode of claim 4, wherein the lithium-containing metal oxide comprises a perovskite compound represented by Formula 1:
LixAyGzO3-δ Formula 1
wherein, in Formula 1,
each A and G are independently at least one of a Group 2 to a Group 16 element, and
0<x≤1, 0<y≤1, 0<x+y 1, 0<z≤1.5, and 0≤δ≤1.5.

### Claim 14 (depends on 13)

The cathode of claim 13, wherein A is at least one of H, Na, K, Rb, Cs, Ca, Sr, Ba, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, or Er,
G is at least one of Ti, Pd, Pb, Fe, Ir, Co, Rh, Mn, Ni, Cr, Ru, Re, Sn, V, Ge, W, Zr, Mo, Hf, U, Nb, Th, Ta, Bi, Ca, Sr, Ba, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Mg, Al, Si, Sc, Zn, Ga, Rb, Ag, Cd, In, Sb, Pt, Au, or Pb, and
0.2<x≤0.7, 0<y≤0.7, 0<x+y<1, 0<z≤1.2, and 0≤δ2≤1.2.

### Claim 15 (depends on 13)

The cathode of claim 13, wherein A is at least one of La, Ce, Pr, Gd, Ca, Sr, or Ba,
G is at least one of Ti, Mn, Ni, Ru, Cr, Co, Ir, Fe, Pd, Pb, Rh, Sn, V, Re, Ge, W, Zr, Mo, Nb, Ta, Hf, or Bi, and
0.2<x≤0.5, 0.4<y≤0.7, 0<x+y<1, 0.8<z≤1.2, and 0≤δ≤1.

### Claim 16 (depends on 13)

The cathode of claim 13, wherein the perovskite compound has an electronic conductivity of about 1×10−6 siemens per centimeter or more at 25° C., and an ionic conductivity of about 2×10−7 siemens per centimeter or more at 25° C.

### Claim 17 (depends on 4)

The cathode of claim 4, wherein the lithium-containing metal oxide comprises a spinel compound represented by at least one of Formula 2 or Formula 3:
Li1±xM2±yO4−δ1 Formula 2
Li4±aM5±bO12-δ2 Formula 3
wherein, in Formulae 2 and 3,
each M is independently at least one of a Group 2 to Group 16 element, and
0<x≤1, 0<y≤1, 0≤δ1≤1, 0<α<2, 0.3<b<5, and 0≤δ2≤3.

### Claim 18 (depends on 17)

The cathode of claim 17, wherein
each M is independently at least one of Ni, Pd, Pb, Fe, Ir, Co, Rh, Mn, Cr, Ru, Re, Sn, V, Ge, W, Zr, Ti, Mo, Hf, U, Nb, Th, Ta, Bi, Ca, Sr, Ba, Y, La, Ce, Pr, Nd, Pm, Sm, Gd, Tb, Dy, Ho, Er, Mg, Al, Si, Sc, Zn, Ga, Rb, Ag, Cd, In, Sb, Pt, Au, or Pb, and
0<x≤1, 0<y≤1, 0≤δ1≤1, 0<α<2, 0.3<b<5, and 0≤δ2≤3.

### Claim 19 (depends on 17)

The cathode of claim 17, wherein the spinel compound is represented by Formula 4:
Li4±aTi5-bM′cO12-δ Formula 4
wherein, in Formula 4,
M′ is at least one of Cr, Mg, Ca, Sr, Sc, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Zr, Hf, V, Nb, Ta, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg, Al, Ga, In, TI, Ge, Sn, Pb, Sb, Bi, Po, As, Se, or Te, and
0.3<α<2, 0.3<b<2, 0.3<c<2, and 0≤δ≤3.

### Claim 20 (depends on 17)

The cathode of claim 17, wherein the spinel compound has an electronic conductivity of about 1×10−6 siemens per centimeter or more at 25° C. and an ionic conductivity of about 1×10−7 siemens per centimeter or more at 25° C.

### Claim 21 (depends on 4)

The cathode of claim 4, wherein the lithium-containing metal compound comprises at least one of a layered compound, a garnet compound, a NASICON compound, a LISICON compound, a phosphate compound, a tavorite compound, a triplite compound, an anti-perovskite compound, a silicate compound, or a borate compound.

### Claim 22 (depends on 4)

The cathode of claim 4, wherein the lithium-containing metal oxide comprises at least one of a layered compound represented by Formula 5, a NASICON compound represented by Formula 6, a LISICON compound represented by Formula 7, a garnet compound represented by Formula 8, a phosphate compound represented by Formula 9, a phosphate compound represented by Formula 10, a tavorite compound represented by Formula 11, a triplite compound represented by Formula 11, an anti-perovskite compound represented by Formula 12, a silicate compound represented by Formula 13, or a borate compound represented by Formula 14:
Li1±xM1±yO2±δ Formula 5
wherein, in Formula 5,
M in Formula 5 is at least one of a Group 2 to Group 16 elements, and
0<x≤0.5, 0<y≤1, and 0≤δ≤1,
Li1+xAxM2-x(XO4)3 Formula 6
wherein, in Formula 6,
each A and M in Formula 6 are each independently at least one of a Group 2 to a Group 16 element,
X is As, P, Mo, or S, and 0<x≤1,
Li8-cAaB′bO4 Formula 7
wherein, in Formula 7,
each A and B′ in Formula 7 are each independently at least one of a Group 2 to a Group 16 element,
c=ma+nb, wherein m is an oxidation number of A, n is an oxidation number of B, and 0<a≤1, and 0≤δ≤1,
LixA3B′2O12 Formula 8
wherein, in Formula 8,
each A and B′ in Formula 8 are each independently at least one of a Group 2 to a Group 16 element, and 3×7,
Li1±xMPO4 Formula 9
Li2MP2O7 Formula 10
wherein, Formulae 9 and 10,
each M in Formulae 9 and 10 is at least one of a Group 2 to a Group 16 element, and 0≤x≤1,
Li1±xM(TiO4)X′ Formula 11
wherein, in Formula 11,
M in Formula 11 is at least one of a Group 2 to a Group 16 element,
T is P or S,
X′ is F, O, or OH, and 0≤x≤1.0,
LixMyOA Formula 12
wherein, in Formula 12,
M in Formula 12 is at least one of a Group 2 to a Group 16 element,
A in Formula 12 is F, C, Br, I, S, Se, or Te, and 2≤x≤3 and 0≤y≤1,
Li2±xMSiO4 Formula 13
wherein, in Formula 13, M is at least one of a Group 2 to a Group 16 element, and 0≤x≤1,
Li1±xMBO3 Formula 14
wherein, in Formula 14,
M in Formula 14 is at least one of a Group 2 to a Group 16 element, and 0≤x≤1.

### Claim 23 (depends on 22)

The cathode of claim 22, wherein the lithium-containing metal oxide has an ionic conductivity of about 1×10−6 siemens per centimeter or more at 25° C.

### Claim 24 (depends on 4)

The cathode of claim 4, wherein the lithium-containing metal oxide is electrochemically stable at a voltage of about 2 volts to about 4 volts, with respect to lithium metal.

### Claim 25 (depends on 1)

The cathode of claim 1, wherein the porous film further comprises an electronic conductor represented by at least one of Formula 15 or Formula 16:
AxB′yO3±δ Formula 15
wherein, in Formula 15,
each A and B′ in Formula 15 are each independently at least one of a Group 2 to a Group 16 element, and
0.8≤x≤1.2, 0.8≤y≤1.2, and 0≤δ≤1.5.
CexMyO3±δ Formula 16
wherein, in Formula 16,
M in Formula 16 is at least one of a Group 2 to a Group 16 element, and
0.6≤x≤1.0, 0≤y≤0.4, and 0≤δ≤0.5.

### Claim 26 (depends on 25)

The cathode of claim 25, wherein
A is at least one of Sr, Ba, or La,
B′ is at least one of Zr, Ce, Sc, Y, In, or Yb, and
M is at least one of Sc, Y, Zr, In, La, Pr, Sm, Gd, or Yb.

### Claim 27 (depends on 1)

A lithium-air battery comprising:
the cathode according to claim 1;
an anode comprising lithium; and
an electrolyte disposed between the cathode and the anode.

### Claim 28 (depends on 27)

The lithium-air battery of claim 27, wherein the electrolyte is a solid electrolyte.

### Claim 29

A method of preparing a cathode, the method comprising:
providing a composition comprising a metal oxide and a binder;
disposing the composition onto a base;
drying the composition on the base to prepare a coating layer;
pressing the coating layer to prepare a sheet; and
heat-treating the sheet in an oxidizing atmosphere at a temperature of about 450° C. to about 800° C. to prepare the cathode.

### Claim 30 (depends on 29)

The method of preparing a cathode of claim 29, wherein the method further comprises:
preparing a stack of coating layers, wherein the stack of coating layers comprises a plurality of the coating layer, prior to pressing the coating layer to prepare a sheet.

### Claim 31 (depends on 29)

The method of preparing a cathode of claim 29, wherein the composition further comprises an organic particle having a size of about 1 micrometer or more.

### Claim 32 (depends on 31)

The method of preparing a cathode of claim 31, wherein an amount of the organic particle is about 5 parts by weight to about 60 parts by weight, based on 100 parts by weight of the metal oxide.

### Claim 33 (depends on 29)

The method of preparing a cathode of claim 29, wherein the metal oxide comprises a lithium-containing metal oxide.

### Claim 34

A cathode configured to use oxygen as a cathode active material, the cathode comprising:
a porous film,
wherein the porous film comprises a metal oxide, wherein the metal oxide is a lithium containing metal oxide represented by Formula 1,
LixAyGzO3-δ Formula 1
wherein, in Formula 1,
each A and G are independently at least one of a Group 2 to a Group 16 element,
0<x≤1, 0<y≤1, 0<x+y≤1, 0<z≤1.5, and 0≤δ≤1.5, and
wherein a surface of the porous film has a root mean square roughness of about 0.01 micrometer to about 1 μm micrometer.