Highly conductive quasi-coaxial electrospun quaternized polyvinyl alcohol nanofibers and composite as high-performance solid electrolytes

作者：Liao Guan Ming; Li Pin Chieh; Lin Jia Shiun; Ma Wei Ting; Yu Bor Chern; Li Hsieh Yu; Liu Ying Ling; Yang Chun Chen; Shih Chao Ming; Lue Shingjiang Jessie^*

来源：Journal of Power Sources, 2016, 304: 136-145.

DOI：10.1016/j.jpowsour.2015.11.025

• Coaxial structure
• Electrospinning
• Direct methanol alkaline fuel cell (DMAFC)
• Conductivity enhancement
• Methanol permeability

Electrospun quaternized polyvinyl alcohol (Q-PVA) nanofibers are prepared, and a potassium hydroxide (KOH)-doped nanofiber mat demonstrates enhanced ionic conductivity compared with a dense Q-PVA film with KOH doping. The Q-PVA composite containing 5.98% electrospun Q-PVA nanofibers exhibits suppressed methanol permeability. Both the high conductivity and suppressed methanol permeability are attributed to the quasi-coaxial structure of the electrospun nanofibers. The core of the fibers exhibits a more amorphous region that forms highly conductive paths, while the outer shell of the nanofibers contains more polymer crystals that serve as a hard sheath surrounding the soft core. This shell induces mass transfer resistance and creates a tortuous fuel pathway that suppresses methanol permeation. Such a Q-PVA composite is an effective solid electrolyte that makes the use of alkaline fuel cells viable. In a direct methanol alkaline fuel cell operated at 60 degrees C, a peak power density of 54 mW cm(-2) is obtained using the electrospun Q-PVA composite, a 36.4% increase compared with a cell employing a pristine Q-PVA film. These results demonstrate that highly conductive coaxial electrospun nanofibers can be prepared through a single-opening spinneret and provide a possible approach for high-performance electrolyte fabrication.

• 出版日期2016-2-1
• 单位长春大学; 清华大学