Effect of drying condition of poly (vinylidene fluoride) binder solution on film adhesion of graphite electrode for lithium batteries
Author(s): SHUI Jiang-lan, DING Chu-xiong, YU Yan, CHEN Chun-hua
Pages: 623-627
Year: 2008 Issue: 6
Journal: JOURNAL OF UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
Keyword: poly (vinylidene fluoride); graphite; crystallinity; adhesion; lithium batteries;
Abstract: The drying conditions of a poly(vinylidene fluoride) (PVDF) solution have a greatinfluence on its crystalinity and binding strength during the preparation of electrode laminates forlithium ion batteries. A peeling experiment was designed to evaluate the mechanical strength ofthe PVDF adhering to graphite. X-ray diffraction and galvanostatic cell cycling were used toevaluate the influence of PVDF binder treated under different thermal conditions. The resultsindicate that for the PVDF binder that is dried and crystallized at a temperature slightly higherthan its melting temperature, it has higher crystallinity and adhesion strength to the graphiteparticles, whether it is soaked in electrolyte or not. This binder-related mechanical property ofthe electrode can improve the cycling performance of the graphite electrode although the capacitymay undergo a gradual rising process during the first 150 or so cycles due to the partial blockingof the electrical conduction path by PVDF initially.
Pages: 623-627
Year: 2008 Issue: 6
Journal: JOURNAL OF UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
Keyword: poly (vinylidene fluoride); graphite; crystallinity; adhesion; lithium batteries;
Abstract: The drying conditions of a poly(vinylidene fluoride) (PVDF) solution have a greatinfluence on its crystalinity and binding strength during the preparation of electrode laminates forlithium ion batteries. A peeling experiment was designed to evaluate the mechanical strength ofthe PVDF adhering to graphite. X-ray diffraction and galvanostatic cell cycling were used toevaluate the influence of PVDF binder treated under different thermal conditions. The resultsindicate that for the PVDF binder that is dried and crystallized at a temperature slightly higherthan its melting temperature, it has higher crystallinity and adhesion strength to the graphiteparticles, whether it is soaked in electrolyte or not. This binder-related mechanical property ofthe electrode can improve the cycling performance of the graphite electrode although the capacitymay undergo a gradual rising process during the first 150 or so cycles due to the partial blockingof the electrical conduction path by PVDF initially.
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