Kynar® PVDF for Separator Coating
Dr. Luc YU, Business Development Engineer, Kynar Fluoropolymer, Arkema China Tianjin, China May 9th 2013


Arkema at a glance
Global producer of specialty chemicals Worldwide No.1 to No.3 in its strongest product lines Total sales 2012: €6.4bn 9 research centers 84 industrial plants* 14,000 employees*


Advantages of Kynar® PVDF Production
Arkema Is Global Leader In PVDF Production, (Since 1963)
Multi Production Sites, USA, Europe, and China
Large Global Production Capacity Plus New Investments To Meet Future Demand Made By Emulsion Polymerization
●
Wide range of solution viscosity Wide range of copolymer composition Better Resin Solubility Improved Electrode Flexibility Higher Interconnectivity (Ionic and Electron Transport)
● ● ● ●


Global Production/R&D /Technical Support


Separator Coating in Lithium Ion Battery
Separator Coating: Kynar Flex® LBG, Kynar Flex® 2801, etc. Electrode Binder: HSV900, 761A, etc.
Electrode Separator Coating Separator Separator Coating Electrode
Separator


Application of Separator Coating
PVDF-HFP coated PE/PP separator
Ceramic/PVDF coated PE/PP separator


Kynar Flex® PVDF in Separator Coating
1. Porous Kynar Flex® PVDF Coating (Smart phones, Tablet PC,etc.) Porous layer Separator
2. Kynar Flex® PVDF + ceramic nano-particles (Electric Vehicle,etc) Ceramic nanoparticle layer
Separator


SEM Pictures of Coated Separator
Separator before Coating
Separator after Coating


Why is Separator Coating favored?
PVDF coated Separator
● Variable shape and slimness of battery ● Absorbs liquid electrolyte: Increase safety ● Stick electrode with separator to increase consistency and cycle life
Ceramic coated Separator
● Reduce risk of internal short from Lithium dendrite: Increase safety ● Reduce the shrinkage of PE/PP substrate: Increase safety


Basic Separator Coating Formulation
Kynar® PVDF Grade: 5~10 wt% in solution
Anti-Solvent: Water, Alcohol, Methanol 10~15% in liquid
Solution mixture coated on Separator. Evaporate solvent and anti-solvent to make porous coating layer Solvent: Acetone 85~90% in liquid Additives: Ceramic nano-particles, Al2O3, etc.


20-251352751
5-16
117-125250022-27140-1452801
34-38151-156LBG
Melt Viscosity (kp) Melting Point (ºC)Kynar Flex ®Grade
Lower adhesion and better high temperature performance
370 % (**)36 %Kynar 2801
360 %(*)27 %Kynar LBG
470 % (**)95 % (**)Competition B
950 %(**)51 % (*)Competition A
80 °C 40 °C EC / DMC / DEC (2:2:1) + LiPF 6(1M)SWELLING (% wt.)
Polymer
(**)Maximum swelling; samples are not weighable (gelfied or destroyed)
Sample Size ：20 x 50 x 1.5 mm 。

Kynar Flex ®LBG is recommended because:
1.It has proper swelling ratio in liquid electrolyte,
2.Keeps structure at high temperature
3.Keeps adhesion between electrode and separator,
4.Keeps good battery performance, such as cycle life,etc.
Emulsion Process
-Kynar Is Made By Emulsion, Already Waterborne, unique to
Arkema
Nano-scale Particle Size
-Arkema Has Patented Technology
New Formulation Development
-Arkema is The World Leader With Extensive Patent Portfolio In Waterborne Technology, Especially Fluoropolymer Coating
Formulation
Kynar Flex®PVDF Copolymer has been used widely in separator coating of lithium ion battery used in consumers’electrics and electric vehicle
Arkema offers Kynar Flex®PVDF with various adhesion and high-temperature performance
Kynar®Waterborne is game changing technology
Arkema is ready to cooperate with battery and separator makers in developing better performed and more
environmental-friendly battery.
Dr. Luc Yu, Shanghai, China: luc.yu@
Mr. Terry Lin, Guangzhou, China: terry.lin@
Dr. Michael Zhu, Shanghai, China: michael.zhu@。