Technical Marketing Engineer SOLVAY - ELIBAMA...Oct 06, 2014 · Milena Stanga Technical Marketing...

GREEN PVDF FOR GREEN BATTERIES

ELIBAMA STAKEHOLDERS CONFERENCE

Newcastle, Oct 14. 2014

Milena Stanga Technical Marketing Engineer

SOLVAY

STATE OF THE ART



• PVDF powder in NMP solvent

• PVDF is a partially fluorinated semi-crystalline polymer

with excellent thermo-mechanical and chemical properties.



Advantages of PVDF

• Stable adhesion during time

• High cohesion

• Long cycle life

• Good chemical affinity with commercial

separator

• Better lamination process

• Good compatibility with artificial graphite

• Low resistivity for power application

Disadvantages of PVDF

• Use of NMP (Toxic & costly)

A NEW WATER BASED

BINDER COMBINING

ADVANTAGES OF

PVDF AND WATER



• Solvay Specialty Polymers has taken advantages of its expertise in

fluorine chemistry and polymerization technologies for design a new

generation of fluoro-polymers for LIB Application

• Solvay introduces a novel fluorinated binder in aqueous dispersion

with proprietary chemical modification (not blending materials) for

improved adhesion and flexibility.



• Solef® PVDF water-based dispersions are stable and have

the special feature of nano-sized primary particles of

PVDF in the shape of spheres

• Latex viscosity: <5 cps [Brookfield, spindle#1, 60 rpm]

• Solid content of latex: 25-35% w

• pH: 3-5 (stable to pH adjustment up to 13)

• Stable to shear stress



• Solef® PVDF water-based ensures continuous film of

binder between active material particles, through

Thermal Process of Film Formation



• 1.Aqueous slurry

Dispersion of AM/binder

• 2. Particles packing

&deformation

aggregation of PVDF primary particles &

water evaporation

• 3.Coalescence

Melting into Mechanically

coherent dry film

• Solef® PVDF water-based ensures continuous film of

binder between active material particles, through

Thermal Process of Film Formation



Graphite PVDF

particles

PVDF film

after film formation

• The chemical modification in Solef® PVDF Latex ensures

higher and more stable adhesion in combination with

flexibility of the final electrode



Solef® PVDF Water Based Binder SBR Water Based Binder

• Applying the proper processing conditions, electrodes

made with Solef® PVDF Latex show same adhesion

level as standard PVDF polymer processed in NMP



0

0,01

0,02

0,03

0,04

0,05

0,06

0,07

0,08

0,09

0,1

Solef® PVDF Latex PVDF in NMP

Pe

elin

g st

ren

ght

(N/c

m)

• Taking advantage of Solef® PVDF Latex high adhesion

and lower volume at equal weight compared to SBR,

reduced amount of binder can be used increasing the

amount of active material (to exploit the theoretical

capacity and energy density of the battery).





• Flexibility is a key property which determines final

performance of batteries. A good binder guarantees the

electrode to be bent in winding or z-fold configuration with

no cracks formation



Lamination Polyolefin

Separator with Electrode

PVDF

latex Lamination

SBR latex NO

Lamination

• Good interphase between electrodes and separator is a key

factor to reduce internal resistance.

• Chemical affinity of PVDF with commercial polyolefin

separators allows to laminate (ensuring better interface)

them together.



• Swelling behavior of the electrode is a key parameter

• The electrode from PVDF latex is perfectly stable to both

stressful treatments, showing very similar performance to

SBR electrode, although pure PVDF polymer film is

gellified at RT and is dissolved at 90°C

0

10

20

30

PVDF XPH859 (Binder 3% v/v) SBR std (Binder 3% v/v)

% U

pta

ke

Swelling @ Room Temperature <1h> <2h> <24h> < % uptake su materiale rimasto >

0

10

20

30

PVDF XPH859 (Binder 3% v/v) SBR std (Binder 3% v/v)

% U

pta

ke

Swelling @ 90°C



• Test: Cycling at 1C at RT

• Testing system: Full cell (pouch cell 383562)

• Anode formulation: 94 % SCMG, 3 % Super P, 1.2 % Solef® Latex, 1.8

% CMC



• Test: Cycling at 1C

• Testing system: Full cell (pouch cell 53437)

• Anode formulation: 89 % LTO, 5 % Super P, 5 % Solef® Latex, 1 %

CMC

Aqueous based

NMP based Aqueous based

NMP based

1C CCCV – 1D

Voltage cut-offs : [1.5V – 2.8V]

RT

1C CCCV – 1D

Voltage cut-offs : [1.5V – 2.8V]

55°C

GREEN PVDF FOR

GREEN BATTERIES



• Towards a fully water-based production process for all

components of the battery:

• Preliminary validation of Solef® PVDF Latex as binder at

high voltage cathode

• NMC 532/carbon black/Solef XPH 859=90/5/5 wt%

• Confirms residual water from all-aqueous processing is not a

concern if routine secondary drying conditions are used.

• More effective and energy efficient to use dry-room air to remove

trace adsorbed water than vacuum pumping for long time periods.



• NMC 532/carbon black/Solef XPH 859=90/5/5 wt%



The ELIBAMA project is granted by the European Commission under the

“Nanosciences, nanotechnologies, materials & new production technologies” (NMP) Theme

of the 7th Framework Programme for Research and Technological Development.

Technical Marketing Engineer SOLVAY - ELIBAMA...Oct 06, 2014 · Milena Stanga Technical Marketing...

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