design of stoichiometric layered potassium transition metal ......h. kim et al. adv. energy mater....

Design of Stoichiometric Layered Potassium

Transition Metal Oxide for K-Ion Batteries

Haegyeom Kim,

Post-doc Fellow in Ceder group

Materials Sciences Division

Lawrence Berkeley National Laboratory

Abstract #: A05-383 October 03 2018 08:00-08:20

Download these slides at http://ceder.berkeley.edu 1

H. Kim et al. Chem. Mater. ASAP (DOI: 10.1021/acs.chemmater.8b03228)

2

- Stoichiometric Layered Potassium Transition Metal Oxide for Re-chargeable

Potassium Batteries.

Chemistry of Materials. 30, 6532 (2018)

- A new strategy for high voltage cathodes for K-ion batteries: Stoichiometric KVPO4F.

Advanced Energy Materials. 1801591 (2018)

- Recent progress and perspective in electrode materials for K-ion batteries.

Advanced Energy Materials. Vol. 8, 1702384. (2018)

- Investigation of potassium storage in layered P3-type K0.5MnO2 cathode.

Advanced Materials. Vol. 29, 1702480. (2017)

- K-ion batteries based on a P2-type K0.6CoO2 cathode.

Advanced Energy Materials, Vol. 7, 1700098 (2017)

3 H. Kim et al. Adv. Energy Mater. 2018, 8, 1702384

0

20,000

40,000

60,000

Potassium

carbonate

790

USD / Ton

USGS Report (2018)

58,643

USD / Ton

13,900

USD / Ton

Cobalt

oxide

Lithium

carbonate

Pri

ce

(U

SD

/ T

on

)

Sodium

carbonate

152

USD / Ton 0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

Fe Co Ni

10,144

58,643

< 100

7,40011,464

Pri

ce

(U

SD

/ T

on

)

Ti V Cr Mn

8,600

Potassium is earth abundant and has lower price than lithium.

K-ion battery system does not require expensive Co element.

Ceder Group

Standard

potentials

(vs. SHE)

Li/Li+

Na/Na+

K/K+

Aqueous -3.04 -2.714 -2.936

PC solvent -2.79 -2.56 -2.88

EC/DEC solvent

(relative value)

0.0 0.3 -0.15

Komaba et al. Electrochem. Commun. 2015, 60, 172,

Lower standard redox potential of alkali ions

Potentially higher working voltage of battery system

Working voltage

Standard redox potential of A/A+

Redox potential of electrode

4

Ceder Group

Komaba et al. Electrochem. Commun. 2015, 60, 172,

Graphite can store and release K ions, but not Na.

It indicates we already have a good anode material!!!

5

Ceder Group

Recently, K-ion batteries attract much attention.

6

2004 2010 2012 2014 2016 20180

10

20

30

40

50

Nu

mb

er

of

pap

ers

Year

Web of science

Accessed, August 15 , 2018

Ceder Group

Transition metal component

High redox activity

2-dimensional ion migration pathways

Good rate capability

Rigid oxide framework

Good cycle stability

Xiang et al. J. Electrochem. Soc. 2015, 162, A1662

Layered transition metal oxides (AxMO2, A= Alkali ion and M=

Transition Metal) have been studied as cathode materials for Li-, Na-,

and K-ion batteries.

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Ceder Group

8

Many stoichiometric LiMO2 and NaMO2 compounds have been used as

cathodes for Li- and Na-ion batteries.

LiCoO2

Y. –I. Jang et al. J. Electrochem. Soc. 2002, 149, A1442 X. Ma et al. J. Electrochem. Soc. 2011, 158, A1307

NaMnO2

Ceder Group

9

K-layered compounds reported to date are K-deficient compositions.

KxMO2 (0.3 ≤ x ≤ 0.7, M = transition metal)

Composition Reference

K0.3MnO2 JES 163 A1295 (2016)

K0.7Mn0.5Fe0.5O2 Nano Lett. 17, 1, 544 (2016)

K0.6CoO2 Adv. Energy Mater. 1700098 (2017)

K0.5MnO2 Adv. Mater. 29, 1702480 (2017)

K0.67Ni0.17Co0.17Mn0.66O2 Electrochem. Commun. 82, 150 (2017)

K0.41CoO2 Chem. Commun., 53, 3693 (2017)

K0.45MnO2 Chem. Eng. J. 356, 53 (2019)

Ceder Group

10

K-transition metal oxides have been investigated as cathodes

for K-ion batteries.

P2-K0.6CoO2 P3-K0.5MnO2

H. Kim et al. Adv. Energy Mater. 1700098 (2017) H. Kim et al. Adv. Mater. 170248 (2017)

1st cycle

Ceder Group

11

P2-K0.6CoO2 P3-K0.5MnO2

H. Kim et al. Adv. Energy Mater. 1700098 (2017) H. Kim et al. Adv. Mater. 170248 (2017)

In the practical cells, K ions should be brought from cathodes.

K-deficient cathode requires pre-potassiation process.

This capacity needs to come from anode or pre-potassiation process.

1st cycle

Ceder Group

12

Most transition metals cannot form stoichiometric

layered structure (KMO2) because of large K ion size.

But, KScO2 and KCrO2 can be stabilized in layered

structure.

KScO2: due to large ionic size of Sc3+.

KCrO2: why?

Most stable structure:

Non-layered

H. Kim et al. Chem. Mater. 18, 6532

Not stable O3

Ceder Group

13

0.0

0.5

1.0

En

erg

y (

eV

/f.u

.)

FeMn

Cr NiCo

O= Octahedral, T= Tetrahedral, Py= Pyramidal sites

O T PyO T PyO T PyO T Py

O T Py

In KMO2 composition, Cr3+ strongly prefers

occupying octahedral site.

In contrast, Mn3+, Co3+, and Ni3+ prefers pyramidal

sites and Fe3+ prefers tetrahedral sites.

2D K arrangements

3D K arrangements

3D K arrangements

Ceder Group

H. Kim et al. Chem. Mater. 18, 6532

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Cr3+ has d3 electron configuration and is thus more

stabilized in octahedral sites than in other sites.

Ceder Group

H. Kim et al. Chem. Mater. 18, 6532

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Mn3+ has d4 electron configuration and thus can be

stabilized in pyramidal sites.

Ceder Group

H. Kim et al. Chem. Mater. 18, 6532

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Fe3+ has d5 electron configuration and thus can be

stabilized in tetrahedral sites.

Competition between K+-K+ interaction

vs. site preference of transition metal

Ceder Group

H. Kim et al. Chem. Mater. 18, 6532

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Stoichiometric O3-type KCrO2 is synthesized.

ICP: K/Cr = 1.02

The particle size: ~1 µm

Ceder Group

H. Kim et al. Chem. Mater. 18, 6532

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K metal anode

0.7 M KPF6 in EC/DEC electrolyte

At 5 mA/g, KCrO2 delivers a reversible capacity ~92 mAh/g.

Multiple plateaus indicate successive phase transition as a function of K

content.

Ceder Group

H. Kim et al. Chem. Mater. 18, 6532

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KCrO2 retains ~60 mAh/g after 100 cycles.

KCrO2 provides a moderate rate capability: 30 mAh/g at 500 mA/g

Ceder Group

H. Kim et al. Chem. Mater. 18, 6532

0 20 40 60 80 100 120 1400

1

2

3

4 2nd

Vo

lta

ge

(V

)

Capacity (mAh g-1)

1st

0 2 4 6 8 10

0

50

100

Re

ten

tio

n (

%)

Cycles

20

Practical feasibility of O3-type KCrO2 cathode was demonstrated in a full

cell with a graphite anode.

Ceder Group

H. Kim et al. Chem. Mater. 18, 6532

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4 3 2 1

0

20

40

60

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0

20

40

0.5

0.6

0.7

0.8

0.9

5 10 15 20 25 13 16 18 20

Two theta (Deg., Mo.)

Cha

rge

D

isch

arg

e

O3 (104)

O’3 (20-2) O’3 (111)

P3(015)

P’3 (201)

P’3 (11-2)

O3 (104)

P’3 (201)

P’3 (11-2)

P3(015)

O’3 (20-2)

O’3 (111)

P3(015)

P3(015)

P’3 (201)

P’3 (11-2)

P’3 (201)

P’3 (11-2)

Tim

e (

Ho

urs

.)

Voltage (V vs. K)

Al peak

x i

n K

xC

rO2

Ceder Group

H. Kim et al. Chem. Mater. 18, 6532

22

4 3 2 1

0

20

40

60

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0

20

40

0.5

0.6

0.7

0.8

0.9

5 10 15 20 25 13 16 18 20

Two theta (Deg., Mo.)

Cha

rge

D

isch

arg

e

O3 (104)

O’3 (20-2) O’3 (111)

P3(015)

P’3 (201)

P’3 (11-2)

O3 (104)

P’3 (201)

P’3 (11-2)

P3(015)

O’3 (20-2)

O’3 (111)

P3(015)

P3(015)

P’3 (201)

P’3 (11-2)

P’3 (201)

P’3 (11-2)

Tim

e (

Ho

urs

.)

Voltage (V vs. K)

Al peak

x i

n K

xC

rO2

Upon K extraction, (006) peak moves to lower angle, which indicates

expansion of c-axis.

It recovers after K insertion, indicating reversible reaction.

O3 (006)

Ceder Group

23

4 3 2 1

0

20

40

60

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0

20

40

0.5

0.6

0.7

0.8

0.9

5 10 15 20 25 13 16 18 20

Two theta (Deg., Mo.)

Cha

rge

D

isch

arg

e

O3

O’3

P’3

Tim

e (

Ho

urs

.)

Voltage (V vs. K)

Al peak

x i

n K

xC

rO2

Upon K extraction, successive phase transition of

O3-O’3-P’3-P3-P’3-P3-O3 is observed.

P3

P’3

P3

O3

P’3

P3

P3

P’3

O’3

Ceder Group

H. Kim et al. Chem. Mater. 18, 6532

24

4 3 2 1

0

20

40

60

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0

20

40

0.5

0.6

0.7

0.8

0.9

5 10 15 20 25 13 16 18 20

Two theta (Deg., Mo.)

Cha

rge

D

isch

arg

e

O3 (104)

O’3 (20-2) O’3 (111)

P3(015)

P’3 (201)

P’3 (11-2)

O3 (104)

P’3 (201)

P’3 (11-2)

P3(015)

O’3 (20-2)

O’3 (111)

P3(015)

P3(015)

P’3 (201)

P’3 (11-2)

P’3 (201)

P’3 (11-2)

Tim

e (

Ho

urs

.)

Voltage (V vs. K)

Al peak

x i

n K

xC

rO2

Upon K extraction, successive phase transition of

O3-O’3-P’3-P3-P’3-P3-O3 is observed. AxCrO2 ( A = Na and K)

x = 0.0 0.25 0.5 0.75 1.00

O’3 P’3

KxCrO2

NaxCrO2

O3

O3

O’3

P’3

P3

P’3

P3 O3

x ~ 0.43

x ~ 0.5

Strong K+-K+ interaction leads to

strong K+/vacancy ordering in KxCrO2 Ceder Group

H. Kim et al. Chem. Mater. 18, 6532

Less screening of electrostatics between K ions by oxygen results in

strong K+/vacancy ordering at given K concentrations, forming

remarkable amount of phase transitions.

25

Alkali ions

Transition

metals

Oxygen

LixCrO2 NaxCrO2 KxCrO2

Ceder Group

In KMO2 system, strong K+-K+ interaction destabilizes the

layered structure.

Stoichiometric KCrO2 can be stabilized in layered structure

because of strong octahedral site preference of Cr3+.

Stability of stoichiometric KMO2: Competition between K+-K+

interaction vs. site preference of transition metal.

KCrO2 delivers a reversible capacity of ~92 mAh/g.

KxCrO2 cathode goes through reversible multiple phase

transitions: O3-O’3-P’3-P3-P’3-P3-O3

26

Gerbrand Ceder,

Chancellor’s Professor

Department of Materials Science and Engineering

27

Thanks to

Dr. Dong-Hwa Seo

Prof. Alexander Urban

Dr. Jinhyuk Lee

Dr. Deok-Hwang Kwon

Prof. Shou-Hang Bo

Tan Shi

Joseph Papp

Prof. Bryan McCloskey

Thank you

Download these slides at http://ceder.berkeley.edu

28

H. Kim et al. Chem. Mater. 30, 6532 (2018)