Advanced Materials for Sodium-Ion Battery Kook Sun...Advanced Materials for Sodium-Ion Battery Energy Storage & Conversion Material Laboratory Advanced Na[Ni 0.25 Fe 0.5 Mn 0.25]O

Energy Storage & Conversion Material Laboratory

Department of Energy Engineering, Hanyang University, Seoul, South Korea

Yang-Kook Sun

Advanced Materials for Sodium-Ion Battery


Advanced Na[Ni0.25Fe0.5Mn0.25]O2 / C-Fe3O4 Sodium-Ion Battery Using EMS Electrolyte for Energy Storage

Nano Letters, 2014, 14, 1620


Introduction (Why sodium?)

Ref. V. Palomares et al., Energy Environ. Sci., 2012, 5, 5884 Ref. http://www.theenergyreport.com Courtesy of Passerini, presentation in Hanyang University, Oct. 10. 2013

SODIUM 0.07-0.37 euro kg-1

LITHIUM 4.11-4.49 euro kg-1

Vast reserves of lithium carbonate salts in Bolivia and South America


Introduction Characteristics of sodium-ion batteries

Courtesy of J.-M. Tarascon

Higher availability of precursors

Na in the Earth: 103 ppm Na in the Sea : 105 ppm

Lower performance than Lithium-ion

Electrode potential (V) Electrode capacity mAh/g

- 3.04 2.71 3860 1166

Li Na

Potentially cheaper than Lithium chemistry


Introduction

Approaches Synthesis of micro-sized NFM cathode to increase tap density via co-precipitation method Enhancement of cycle performance and volumetric energy density using C-Fe3O4 anode Improvement of high potential stability using the 1M NaClO4 in ethyl methanesulfonate

(EMS) + 2vol% fluoroethylene carbonate (FEC) electrolyte

Low tap density Low volumetric energy density (tap density: hard carbon: 1.8 g cm-3, Fe3O4: 5.17 g cm-3)

Limited operating voltage window

Problems

Typical Approaches Hard carbon anode Nano-sized cathode Modified carbonate electrolyte


Properties of EMS based electrolyte

Linear sweep voltammetry (LSV)

Arrhenius plot of conductivity

The anodic stability of the electrolyte can be further increased to 5.6 V versus Na/Na+ by replacing the PC with EMS.

Ionic conductivity of the EMS based electrolyte is slightly higher than PC electrolyte.

EMS

Cathodic sweep Anodic sweep

3.0 3.2 3.4 3.6 3.8 4.03

4

5

6

7

8T / oC

1M NaClO4 in PC + 2 vol% FEC 1M NaClO4 in EMS + 2 vol% FEC

Cond

uctiv

ity /

mS

cm-1

1000 T-1 / K-1

-3060 50 3040 20 10 0 -10 -20


M(SO4)xH2O (M=Ni,Fe,Mn) NH4OH

Formation of M(OH)2xH2O

M(OH)2

Na[Ni0.25Fe0.5Mn0.25]O2

CSTR

Filtering & Drying

Sodiation

Particle Size and Tap Density

pH Temperature Conc. of the solution Stirring speed

NaOH

Synthesis of Na[Ni0.25Fe0.5Mn0.25]O2 via Co-precipitation method

Na2CO3

Ni,Fe,Mnsoln


NFM oxide shows approximately 8 m particle size with spherical morphology (Tap density: 2.1 g cc-1) NFM powders show O3-type layer structue with a space group of R-3m

SEM & XRD results of Na[Ni0.25Fe0.5Mn0.25]O2 cathode material Precursor hydroxide particle

Calcined oxide particle 2 m

2 m

Lattice parameters a () c () Na[Ni0.25Fe0.5Mn0.25]O2 2.9907(1) 15.9889(5)

NaFeO2 3.03 16.11

Na[Ni0.5Mn0.5]O2 2.9901(1) 15.9329

10 20 30 40 50 60 70 80 90 100

0

5000

10000

202

Inte

nsity

/ A

.U.Cu K 2 / degree

208

02701

1120

111

602

111

311

010

810

7

105

104

006/1

0210

1

003


XANES results of pristine Na[Ni0.25Fe0.5Mn0.25]O2 cathode material

8320 8340 8360 8380

8328 8331 8334 8337

Norm

alize

d ab

sorp

tion

/ A.U

.

Photon energy / eV

NiO Na[Ni0.25Fe0.5Mn0.25]O2

7100 7120 7140 7160 7180

7112 7116 7120

Norm

alize

d ab

sorp

tion

/ A.U

.

Photon energy / eV

Fe2O3 Na[Ni0.25Fe0.5Mn0.25]O2

6520 6540 6560 6580 6600

6540 6544

Norm

alize

d ab

sorp

tion

/ A.U

.

Photon energy / eV

Mn2O3 Na[Ni0.25Fe0.5Mn0.25]O2

As prepared Na[Ni0.25Fe0.5Mn0.25]O2

Ni2+Fe3+ Mn4+

Average oxidation state of Ni, Fe, and Mn are 2+, 3+, and 4+, respectively.

Electric conductivity- 6.6 x 10-7 S cm-1 for Na[Ni0.25Fe0.5Mn0.25]O2 - 1.6 x 10-7 S cm-1 for Na[Ni0.5Mn0.5]O2


Structural changes of Na[Ni0.25Fe0.5Mn0.25]O2

The electrode delivers a high capacity of 140 mAh g-1 with an efficiency of 93%

On charge O3-type layer structure is transformed to the P3-type monoclinic structure andtransformed back into the O3-type structure on discharge.

0 50 100 150

2.0

2.5

3.0

3.5

4.00.0 0.1 0.2 0.3 0.4 0.5 0.6

g

e

f

dc

a

Volta

ge

/ V

Specific capacity / mAh g-1

b

in Na1-Ni0.25Fe0.5Mn0.25O2

15 35 40 45 50 55 60 65 70

P3

O3

NaFeO2 (PDF # 82-1495) Na0.5FeO2 (PDF # 82-1496)

a, = 0, charge b, = 0.2, charge c, = 0.4, charge d, = 0.6, charge e, = 0.4, discharge f, = 0.2, discharge g, = 0.1, discharge

Inte

nsity

/

A.U

.Cu K 2 / degree

Al

O3

2.1-3.9V, 13 mA g-1 (0.1 C-rate)


XANES results of charge and discharge end electrode Charge & discharge end state of Na1-x[Ni0.25Fe0.5Mn0.25]O2 (x=0 or 0.62)

8330 8340 8350 8360 8370

8331 8334

Photon energy / eV

NiO Na[Ni0.25Fe0.5Mn0.25]O2 Charge end Discharge end LiNiO2

Nor

mal

ized

abs

orpt

ion

/ A.U

.

7110 7120 7130 7140

7113 7116

Nor

mal

ized

abs

orpt

ion

/ a.u

.

Photon energy / eV

Fe2O3 Na[Ni0.25Fe0.5Mn0.25]O2 Charge end Discharge end

6540 6550 6560 6570

6540 6543 6546

Nor

mal

ized

abs

orpt

ion

/ a.u

.

Photon energy / eV

Mn2O3 Na[Ni0.25Fe0.5Mn0.25]O2 Charge end Discharge end Li[Ni0.5Mn0.5]O2

Mn4+

Average oxidation state of Ni, Fe varies as the desodiation proceeds with Ni2+ to Ni4+ and Fe3+ toFe4+ at the end of charge, while Mn ions keeps its original oxidation state of Mn4+

On discharge, the average oxidation states of the transition metals are recovered to theiroriginal values


Electrochemical Properties of Na[Ni0.25Fe0.5Mn0.25]O2 1st charge/discharge profilesCut-off: 2.1 3.9V (0.1C = 13 mA g-1)

Na-NFM cathod shows good capacity retention: 90.4% at 25oC (1C), 86% at 55oC (1C), 80%at 0oC (0.5C), and 80% at 0oC (1C) after 50th cycles.

High rate capability was attributed to the weak electrostatic interaction of the NFM cathodethat favors an easy Na+ diffusion across its structure.

Electrolyte: 1M NaClO4 in EMS + 2vol% FEC

0 10 20 30 40 5060

90

120

150 0.5 C, 25 oC 1 C, 25 oC 1 C, 55 oC

10C

7C5C

3C

2C1C0.5C

0.2C

0.5 C, 0 oC 1 C, 0 oC C-rate, 25 oC

Disc

harg

e ca

paci

ty /

mAh

g-1

Number of Cycle

0.1C

0

20

40

60

80

100

Effic

ienc

y / %

0 20 40 60 80 100 120 140 1601.5

2.0

2.5

3.0

3.5

4.0

10C

Volta

ge /

VSpecific capacity / mAh g-1

0.1C


Ar atmosphere

Feed Stoichiometric ratio of FeCl36H2O, sucrose dissolved into ethylene glycol

Hydrothermal treatment (200oC-48h)

Washing, filtering

Calcination & grinding Temperature : 700oC-1h

Sodium acetate, PEG400 also dissolved into

solution

stirring

C-Fe3O4 composite

Dried in an oven at 80oC-24h DI water and ethanol washing

2g Fe3O4 + 0.2g pitch in NMP solution

Synthesis of C-Fe3O4 composite via hydrothermal


XRD patterns & SEM, TEM images of prepared C-Fe3O4 particles

C-Fe3O4 consists of agglomerates of primary particles having a size of about 50-70nm with uniformly distributed and coated by carbon layer.

XRD patterns shows a crystalline Fe3O4 inverse spinel structure with Fd3m space group.

200 nm

Electronic conductivity: 2.3 x 10-3 S cm-1

a = 8.3923

x y

z


Electrochemical Properties of presodiated C-NaxFe3O4

C-NaxFe3O4 electrode show a very stable capacity delivery over 50 cycles at each rates.

In tests to rates as high as 10 C-rate (2,000 mA g-1), the anode still exhibited a high capacity of157 mAh g-1, which is much better compared to that of hard carbon.

charge/discharge profiles Cut-off: 0 2.0V (20 mA g-1)

0 10 20 30 40 50

120

160

200

240

10C 0.1 C 0.5 C 1 C C-rateCa

paci

ty

/ m

Ah g

-1

Number of Cycle

7C5C3C

2C1C

0.5C0.2C0.1C

0

20

40

60

80

100

Effic

ienc

y / %

0 50 100 150 200-0.50.00.51.01.52.02.53.0

10C

Volta

ge /

VSpecific capacity / mAh g-1

0.1C

Electrolyte: 1M NaClO4 in EMS + 2vol% FEC


a b

100 nm

Fe metal

c

100 nm

As prepared C-Fe3O4

TEM images of C-Fe3O4 with charge and discharge end state

Charging to 0V After 50th cycle discharge end

The presence of Fe metal nanoparticles at the end of the charge state indicated the conversion process.

The cycled electrode didnt show such a morphological change, assuring electrode stability.


Scheme image of Na[Ni0.25Fe0.5Mn0.25]O2 / C-Fe3O4 full cell

V

Na[Ni0.25Fe0.5Mn0.25]O2 + Fe3O4 Charge

Discharge

e- e- + -

NaFe3O4 + Na1-[Ni0.25Fe0.5Mn0.25]O2

Na[Ni0.25Fe0.5Mn0.25]O2 C-NaxFe3O4

Intercalation Conversion

E M S

Na+ Na+

Na+ Na+

Na+

Na+

Na[Ni0.25Fe0.5Mn0.25]O2+NaxFe3O4 Na1-[Ni0.25Fe0.5Mn0.25]O2+Na+xFe3O4(Na2O+Fe+Fe3O4)


Electrochemical Properties of Na[Ni0.25Fe0.5Mn0.25]O2/C-NaxFe3O4 full cell

cycle properties profilesCut-off: 0.5 3.6V (0.1C = 13 mA g-1)N/P ratio: 1.2

The full cell shows a good capacity retention for extensive cycling with high Coulombicefficiency approaching almost 100% ; 76.1% at the 150th cycle

The full cell also show an excellent rate capability (130 mAh g-1 at 0.1C, 72 mAh g-1 at 10C-rate)

0 30 60 90 120 1500.00.51.01.52.02.53.03.54.04.5

1st cycle (activation) 2nd cycle

Volta

ge /

V

Specific capacity / mAh g-1 3 6 9 12 15 1860

90

120

150

Fe3O4/NFM full cell

10C7C

3C5C

2C1C

0.5C0.1C

Dis

char

ge c

apac

ity /

mA

h g-

1Number of Cycle

0.2C

0 30 60 90 120 1500

30

60

90

120

150

180

Fe3O4/NFM full cell, 0.5 C cycle discharge capacity Fe3O4/NFM full cell, 0.5 C cycle charge capacity

Disc

harg

e ca

paci

ty /

mAh

g-1

Number of Cycle0

20

40

60

80

100

Efficiency

Effic

ienc

y / %


Conclusions

EMS based electrolyte show a higher voltage window and ionic conductivity compared with PC based electrolyte

O3-type layered Na[Ni0.25Fe0.5Mn0.25]O2 cathode with spherical morphology were successfully synthesized via co-precipitation method.

The Na[Ni0.25Fe0.5Mn0.25]O2 cathode shows the high capacity (140 mAh g-1), good cycle retention, and rate capability.

C-Fe3O4 nano composite anode was synthesized via hydrothermal process.

The C-NaxFe3O4 anode exhibits stable capacity of 200 mAh g-1 with an excellent rate capability

Na[Ni0.25Fe0.5Mn0.25]O2/NaClO4 in EMS/C-NaxFe3O4 full cell delivered a rechargeable capacity of 130 mAh g-1 with good cycle retention and outstanding rate capability.


Nat. Commun., 2015, 7865

FCG Na[Ni0.60Co0.05Mn0.35]O2 as a cathode material for high energy density sodium-ion batteries


Schematic diagram of the FCG Na[Ni0.6Co0.05Mn0.35]O2

Advantages Reduction of surface area of secondary micron particles by rod-shaped primary particles Increase of Li+ or Na+ diffusion rate along with the direction of nano-rod Increase of tap density of micron spherical morphology (energy density) Increase of discharge capacity through the inner high Ni composition Increase of thermal stability and cycle retention through the outer high Mn composition


5m0 2 4 6

0

20

40

60

80

Ni Co Mn

A

tom

ic ra

tio /

%

Distance / m

Hydroxide Precursor

Cross-sectional TEM and EPMA Results

Hydroxide Precursor Sodiated Oxide

0 2 4 60

20

40

60

80

Ni Co Mn

Atom

ic ra

tio /

%

Distance / m

Sodiated Oxide


XPS spectra of Ni for FCG Na[Ni0.6Co0.05Mn0.35]O2 particle

Ni2+:Ni3+ = 61:39

Inte

nsity / A

.U.

Ni2+:Ni3+ = 37:63

859 858 857 856 855 854 853 852 851

Center

As-measured Ni2+

Ni3+ Baseline

Binding energy / eV

Surface


0 40 80 120 160

2

3

4

Specific capacity / mAh (g-oxide)-1

Volta

ge

/ V

2

3

4

145 mAh g-1C.C.

FCG157 mAh g-1

0 10 20 30 40 50 60 70 80 90 1000

30

60

90

120

150

180

62.4%

C.C. FCG


Volta

ge

/ V

4.2%

30

60

90

120

150

180

45.0%

83.3%

55oC

30oC

Electrochemical Performances of the FCG & C.C.

0.1 C-rate0.5 C-rate

C.C.: Conventional Cathode with same composition Na[Ni0.6Co0.05Mn0.35]O2


100 150 200 250 300 350 400

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

293.5oC

FCG, Na0.36[Ni0.60Co0.05Mn0.35]O2: 172 J g-1

C.C., Na0.44[Ni0.60Co0.05Mn0.35]O2: 322 J g-1

Heat

flow

/

W g

-1

Temperature / oC

266.5oC

DSC, TGA, and In-situ XRD of FCG & C.C.

0 100 200 300 400 500 6006065707580859095

100105110

FCG, Na0.36[Ni0.60Co0.05Mn0.35]O2 C.C., Na0.44[Ni0.60Co0.05Mn0.35]O2

2.2 %4.8 %6.0 %

8.8 %

11.9 %

Wei

ght

/ %

Temperature / oC

9.1 %

15 16 30 40 50 60 70

600 oC500 oC400 oC300 oC200 oC

RT

SC SS

2 (=1.54) / Degree

S

SS

C

P: Monoclinic P3S: Spinel Fd3m M3O4C: Cubic Fm3m MO

100 oC

PPPPPPPPP

PP

C.C.

15 16 30 40 50 60 70

S SSS

C

PPPPPPPP

P: Monoclinic P3S: Spinel Fd3m M3O4C: Cubic Fm3m MO

Inte

nsity

/

A.U

.

2 (=1.54) / Degree

PPP

600 oC500 oC400 oC300 oC200 oC

RT100 oC

FCG

400, 300 oC

280, 240 oC


Long-term cycling behavior & rate capability of C/Na[Ni0.60Co0.05Mn0.35]O2FCG & C.C.

0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 3000

40

80

120

160

200

C.C. : 49.2% FCG : 80%

D

isch

arge

capac

ity

/ mA

h (g-o

xide)

-1

Number of Cycle

0.5 C-rate between 1.5-3.9 V

6065707580859095100105

Eff

icie

ncy

/ %

0 40 80 120 160 2001

2

3

4

0.1C 0.2C 0.5C 1C 2C 3C 5C 7C 10C


Volta

ge

/ V

2

3

4

82 mAh g-1

Bulk

FCG

127 mAh g-1

0 40 80 120 160 2001

2

3

4

82 mAh g-1

0.1C 0.2C 0.5C 1C 2C 3C 5C 7C 10C


Volta

ge /

V

127 mAh g-12

3

4

C.C.

FCG

BET : 0.77 m2 g-1 for FCG1.17 m2 g-1 for C.C.


Conclusions The FCG spheres with long rod-shaped primary particles was

successfully synthesized via a coprecipitation process. The FCG cathode material delivered very high reversible capacity,

157 mAh g-1; 80% capacity retention after 300 cycles and outstanding safety.

The high capacity mainly derived from the Ni2+/3+/4+ redox reaction. Additionally, the lower surface area provided by the nanorod-shaped morphology is beneficial for reducing the contact area with the electrolyte.

These excellent properties were not ever achieved in previous sodium related papers, especially high-Ni systems.

These batteries should be able to compete with lithium batteries in terms of cost, battery performance, and safety.


Thank you or your attention !

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Advanced Materials for Sodium-Ion Battery Kook Sun...Advanced Materials for Sodium-Ion Battery Energy Storage & Conversion Material Laboratory Advanced Na[Ni 0.25 Fe 0.5 Mn 0.25]O