carbonaceousanode materials and conductiveadditives as key...

Carbonaceous Anode Materials and Conductive Additives

as Key To Higher Performance Lithium-ion Batteries

7th International Automotive Battery Conference Europe

31 January 2017

Michael E. Spahr

Technology Cluster Director, Energy & Electronic Materials

IMERYS Innovation, Bodio TI, Switzerland

IMERYS Graphite & Carbon in Lithium-Ion Battery Applications

31 January 2017 AABC20172

Imerys Graphite &

Carbon in numbers

500+ employees

including 30+ in R&D

6 industrial sites

1000+ customers

2 R&D laboratories

LAC-DES-ILES (QC) CANADA

NATURAL GRAPHITE MANUFACTURING

TERREBONNE (QC) CANADA GRAPHITE PROCESSING PLANT

SALES OFFICE

PARIS, FRANCE

HEADQUARTERS IMERYS

BIRONICO, SWITZERLANDHEADQUARTERS IMERYS G&C

SALES OFFICE

BODIO, SWITZERLANDSYNTHETIC GRAPHITE MANUFACTURING

R&D CENTER

WILLEBROEK, BELGIUM

CARBON BLACK MANUFACTURING

SEOUL, SOUTH KOREA

SALES OFFICE

SHANGHAI, CHINA

SALES OFFICE

Headquarters

Sales Offices

R&D Laboratories

Industrial Sites

OTJIWARONGO, NAMIBIA

NATURAL GRAPHITE MANUFACTURING

KAWASAKI, JAPANR&D LABORATORY

TOKYO, JAPANSALES OFFICE

KITAKYUSHU, JAPANSURFACE TREATMENT PLANT

Carbon in Electrochemical Lithium-Ion Cells


Li+

negative electrode (anode)

positive electrode (cathode)

e-

separator IMERYS carbon products are

inside the positive and the

negative electrode

electrolyte (in electrode pores)

carbon active material

conductive graphite

conductive carbon black

binder


active material

conductive graphite


binder

copper

current collector

aluminum

current collector

current collector

coating

+

-

Carbonaceous Anode Materials and Conductive Additives as Key To

Higher Performance Lithium-ion Batteries

Carbon conductive additives for the positive electrode

Carbon conductive additives for the negative electrode

Electrochemically active carbon materials

Carbon/silicon composites

Carbon Black and Graphite Additives in the Positive Electrode


0.1

1

10

100

1000

104

0 1 2 3 4 5 6 7 8

KS6L

SFG6L

Super C45

Super C65

Ele

ctr

ica

l R

es

isti

vit

y [

cm

]

Carbon Amount [wt.%]

0.1

1

10

100

1000

104

105

0 2 4 6 8 10 12

Super C65

KS6L

Super C45

SFG6L

Ele

ctr

ica

l R

es

isti

vit

y [

cm

]

Carbon Additive Amount [wt. %]

200nm 100000 : 1

TEM-Abbildung

Probenbezeichnung:

Super P Li

Datenträgerkennung: TEM_DB3_595XV847_0_0

Bildnummer: 32847

19517

Auftrags-Nr.: A060024276

Bearbeiter: Klehm

Präparation:

Isoprop./Wasser disp.aufgetr.

200 nm

C in LiCoO2

C in LiFePO4

Scanning

electron

microsopy

Transmisson

Electron

Microscopy

Super C65

Conductive

carbon black

KS 6L

graphite

1 mm

Conductive Carbon Black and Graphite Additives in NMC Electrodes


Low resistivity

High density

1:3

1:13:1

CB

G

1:3

1:1

3:1CB

G

C-NERGYTM KS 6L graphite and Super C65 conductive

carbon black at different carbon black :graphite ratios

and a total of 2 wt.% of conductive carbon mass in

NMC.

Press densities at 450 kg cm-1

of NMC/carbon mixtures

Electrical resistivity of NMC/carbon

mixtures

Mixtures of graphite and conductive carbon

black combine

• sufficient electrical conductivity with

• increased compressibility

at low carbon volume fractions.

0 25 50 75 1002.84

2.86

2.88

2.90

2.92

2.94

De

ns

ity

(g

cm

-3)

Graphite Amount (%)

0

2

4

6

8

Ele

ctr

ica

l R

es

isti

vit

y (

k

cm

)

Graphite as Compaction Aid in the Conductive Electrode Mass


*NMC electrodes with 4 wt.% carbon conductive mass/5 wt.% PVDF binder material

1C/1D, 1 M LiPF6 in EC/EMC 1:3 (w/w)

0 20 40 60 800

20

40

60

80

100

120

140

160

180

Super C65

Super C65/KS 6L (1:1 wt.)

Sp

ec

ific

Ch

arg

e (

mA

h g

-1)

Cycle Number

The graphite additive improves the electrode

compressibility and charge density*

0 20 40 60 800

50

100

150

200

250

300

350

400

Ch

arg

e D

en

sit

y (

mA

h L

-1)

Cycle Number

Super C65

Super C65/KS 6L (1:1 wt.)

Similar electrode resistivity leads to a similar

specific charge of the electrode*

Adhesion of NMC Electrodes


Mixed conductive graphite/carbon black masses show better adhesion of the

electrode on the current collector foil than pure conductive carbon black.

Graphite Additives in the Negative Electrode


Density of C-NERGYTM ACTILION 1 electrodes

containing C-NERGYTM SFG 15L

5 mm

SFG 15L

graphite

0 50 100 1501.3

1.4

1.5

1.6

1.7

1.8

2 % SFG 15L

5 % SFG 15L

8 % SFG 15L

Ele

ctr

od

e D

en

sit

y (

g c

m-3

)

Press Force (kN cm-2)

Binder material: 1.5 wt.% SBR/1.5 wt.% CMC

Influence of C-NERGYTM SFG 15L on the cycling

stability of C-NERGYTM ACTILION 1 electrodes

0 10 20 30 40 50300

320

340

360

380

400

Sp

ec

ific

Ch

arg

e (

mA

h g

-1)

Cycle Number

0 % SFG 15 L

10 % SFG 15 L

Lithium half-cells, 1C/3D (CCCV)

Binder material: 1.5 wt.% SBR/1.5 wt.% CMC

Electrode density: 1.7 g cm-3

Electrolyte: 1 M LiPF6 in EC/EMC 1:3 (w/w)

Graphite Additives in the Negative Electrode


*Symmetric coin cell, **Lithium metal coin half-cell

Binder: 1.5 wt.% SBR/1.5 wt.% CMC

Electrode density: 1.7 g cm-3

Electrolyte: EC/EMC 1:3 (w/w), 1 M LiPF6

Influence of C-NERGYTM SFG 15L graphite on the

resistance and specific charge of C-NERGYTM

ACTILION 1 electrodes

0 20 40 60 80 10020

30

40

50

Ele

ctr

od

e R

esis

tan

ce (

)

Graphite Additive Amount (%)

300

320

340

360

380

400

Sp

ecif

ic C

harg

e (

mA

h g

-1)

DCR @ 50 % SOC, 1C (20 s)*

Specific charge @ 0.2 C**

Influence of C-NERGYTM SFG 15L graphite on the

specific charge retention of C-NERGYTM

ACTILION 1 electrodes at 2 C cell discharge rate*

0 10 20 30 40 50 60 70 80 90 10050

60

70

80

90

100

Ch

arg

e R

ete

nti

on

2C

/0.2

C (

%)

Graphite Additive Amount (%)

Carbon in the Lithium-ion Battery Negative Electrode


J. R. Dahn et al. Science 1995, 270, 590.

0.0 0.2 0.4 0.6 0.8 1.0 1.20.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

Po

ten

tia

l vs. L

i/L

i+

x in LixC

6

Soft Carbon

Hard Carbon

Graphite

or x/372 mAh g-1

Passivation

1st Electrochemical Lithium Insertion

Po

ten

tial

vs. L

i/L

i+(V

)Graphite

Long-range order stacking of

carbon layers

Neat stacking, but short-range order

No neat stacking, isotropic

microporosity

Soft

carbon

Hard

carbon

Natural and Synthetic Graphite Active Materials


Li+Li+

20 mm

Flake graphite (hindered Li+ diffusion)

Isometric graphite (easy Li+ diffusion)

20 mm

Li+Li+

Current collector/electrode cross-sections

Spherical natural graphite

Isotropic synthetic graphite

Source: Wachtler et al. Spring Meeting

AKK Carbon (2016)

Swelling of Graphite Negative Electrode


Isotropic graphite

Swelling of Graphite Negative Electrode


Anisotropic graphite

Graphite Anode Materials for FEV Lithium-Ion Batteries


Development objectives at cell level Development objectives at material (electrode) level

Durability

Safety

Energy Power

Chargeability

Trade-off

▪ High crystallinity synthetic or natural graphite

(min. 340 Ah kg-1, min. 500 Ah L-1)

▪ Low surface area

(min. 90 % coulombic efficieny in the 1st cycle)

▪ Low crystalline surface morphology

(stable SEI, low cell gassing)

▪ Isotropic texture, low swelling

(min. 3000 cycles/80 % capacity retention)

▪ Isotropic texture and particle shape

(3C discharge/80 % capacity retention)

▪ Consistent batch-to-batch quality, surface properties

(easy processing in aqueous electrode manufacturing)

▪ Sustainable large scale manufacturing processes

(Low CO2 footprint, environmentally benign, high yield)

▪ Cost efficient

ACTILION B: Surface Properties created by Surface Treatment


▪ Raman Spectroscopy

▪ Porosity

Surface mod.

Raw graphite

Surface modifiedRaw graphite

Graphitization

degree

ACTILION B: Specific Charge and Coulombic Efficiency


10 mm

5 mm

C-NERGYTM graphite

material

Reversible specific

charge

(mAh g-1)

Irreversible

specific charge

(mAh g-1)

Coulombic efficiency

1st cycle

(%)

Spherical NG 364 30 92

ACTILION B-001 357 28 93

ACTILION B-002 351 37 91

ACTILION B-003 341 38 90

Spherical NG ACTILION B-002

Lithium half-cell (coin cell)

Electrolyte: 1 M LiPF6 in EC/EMC 1:3 (w:w)

Binder: 1.5 wt.% SBR/1.5 % wt. CMC

Current: 50 mA/g (CCCV)

SEM

ACTILION B: Cycling Stability and Electrode Impedance


**Symmetric coin cell, 50 % SOC



*Lithium-ion coin cell with NMC positive electrode

Electrolyte: 1 M LiPF6 in EC/EMC 1:3 (w:w), 1 wt.% VC


Charge : 2C to 4.2V (CCCV at 0.1C)

Discharge : 1C to 2.8V

▪ Cycling stability at 2C/1D* ▪ Impedance spectroscopy**

0 50 100 150 200 2500

10

20

30

40

50

60

70

80

90

100

Cap

ac

ity R

ete

nti

on

(%

)

Cycle Number

Spherical NG

ACTILION B-001

ACTILION B-002

ACTILION B-003

0 5 10 150

5

10

15

-Z'' (

)Z' ()

Spherical NG

ACTILION B-001

ACTILION B-002

ACTILION B-003

ACTILION B: Electrode Resistance and High Currant Rate Discharge


DCR ()

Spherical NG 19.5

ACTILION B-001 25.5

ACTILION B-002 22.7

ACTILION B-003 24.1

2C/0.2C (%) 3C/0.2C (%)

Spherical NG 96.0 72.0

ACTILION B-001 97.5 74.2

ACTILION B-002 92.2 66.7

ACTILION B-003 98.5 78.9

*Symmetric coin cell, 50 % SOC, 1C pulse (20 s)



▪ Direct current resistance of electrodes* ▪ High current rate continuous discharge**

**Lithium coin half-cell



0 20 40 60 80 1000.0

0.5

1.0

1.5

Po

ten

tia

l v

s.

Li/L

i+

SOC (%)

0.2C

2C

3C

ACTILION B-003

CO2 Footprint of the C-NERGYTM ACTILION B Negative Electrode Materials


To

n o

f C

O2e

per

to

n o

f g

rap

hit

e p

rod

uce

d

4,7 t 12,4 t 13.0 t

Electric Vehicles

From 250 000 units produced in 2015 to 2 000 000 units produced In 2025 using a CAGR of 23,11%

Simulation based on a 25kWh battery pack model

Up to 1988 ktonsof CO2e SAVED

Process

Raw materials &

transport

4

8

12

0

Synthetic graphite Natural graphiteACTILION B-002

64% reduction of CO2e per ton of

graphite produced

Study by: tallis consulting (2016)

1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014 2016

0

500

1000

1500

2000

2500

3000

3500

4000

Cell

Ca

pac

ity

[m

Ah

]

Calendar Year

Technology Evolution of the Negative Electrode Material


Coke/

Hard

carbon

Graphitic

carbon

New cathode

(NCA, NMC)

C/Si composites

18650

Cell

Evolution of the lithium-ion battery negative

electrode technology for PHEV and FEV*nd FEV

2015-2*Source: Boston Consulting Group, 2016

Calendar Year

Nano-Silicon/Graphite Composite Electrodes


0 10 20 30 40 50 60 70 80 90 100300

400

500

600

700

800

900

1000

1100

Sp

ec

ific

Ch

arg

e [m

Ah

g-1

]

Cycle Number

8 % Silicon

14 % Silicon

0 % Silicon

▪ Capacity increase of graphite electrode by addition of

particulate nano-silicon

Lithium-half cell (coin cell)

Electrolyte: 1 M LiPF6 in EC/DEC 3:7 (v,v), 2 wt.% FEC

Binder: 6 wt.% CMC/PAA (1:1)

50 mA g-1 CCCV Scanning electron microscopy

Influence of Carbon Additives on Silicon/Carbon Composite Electrode

Performance


Negative electrode composition Electrochemical results

Silicon

[wt.% ]

ACTILION 1

[wt.% ]

SFG 15L

[wt.% ]

BND 15

[wt.% ]

Super C45

[wt.% ]

CMC/PAA Discharge

capacity 5th

cycle

[mAh/g]

Relative

capacity

loss cycle

5-15 [% ]

1st Cycle

coulombic

efficiency

[% ]

Nano-

Silicon

Graphite Graphite Graphite Carbon

black

Binder

material

14 80.0 6.0 481 27 86

14 68.8 5.6 5.6 6.0 665 10 84

14 72.0 5.6 2.4 6.0 615 12 84

14 72.0 5.6 2.4 6.0 619 14 86

Carbon in Electrochemical Lithium-Ion Cells


Li+

negative electrode (anode)

positive electrode (cathode)

e-

separator IMERYS carbon products are

inside the positive and the

negative electrode


carbon active material

conductive graphite


binder


active material

conductive graphite


binder

copper

current collector

aluminum

current collector

current collector

coating

+

-

Thank you for your attention.

The support of the IMERYS R&D team is

gratefully acknowledged.

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