4. 阿科玛PVDF共聚物在锂电池隔膜涂层中的应用

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.