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A Flexible Ionic Liquid Gelled PVA‐Li 2 SO 4 Polymer Electrolyte for Semi‐Solid‐State Supercapacitors
Author(s) -
Zhang Xing,
Wang Liangliang,
Peng Jing,
Cao Pengfei,
Cai Xiaosheng,
Li Jiuqiang,
Zhai Maolin
Publication year - 2015
Publication title -
advanced materials interfaces
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.671
H-Index - 65
ISSN - 2196-7350
DOI - 10.1002/admi.201500267
Subject(s) - supercapacitor , materials science , capacitance , ionic liquid , electrolyte , quasi solid , ionic conductivity , chemical engineering , electrode , vinyl alcohol , polymer , composite material , dye sensitized solar cell , organic chemistry , chemistry , engineering , catalysis
A novel high‐performance flexible gel polymer electrolyte (FGPE) for supercapacitors is prepared by a freeze‐drying method. In the presence of 1‐butyl‐3‐methylimidazolium chloride (BMIMCl) ionic liquid, Li 2 SO 4 can easily be added into poly(vinyl alcohol) (PVA) aqueous solution over a large concentration range. The resultant FGPE demonstrates considerably high ionic conductivity (37 mS cm −1 ) and a high fracture strain at 100% elongation at the optimal weight ratio of PVA:BMIMCl:Li 2 SO 4 = 1:3:2.2. The supercapacitor fabricated with the resultant FGPE and activated carbon electrodes shows an electrode‐specific capacitance of 136 F g −1 with a stable operating voltage of 1.5 V, a maximum energy density of 10.6 Wh kg −1 , and a power density of 3400 W kg −1 . Double supercapacitors in series can efficiently drive a light emitting diode (LED) bulb for over 5 min and the retention of the specific capacitance reaches 90% even after 3000 charge–discharge cycles. The ionic conductivity and charge–discharge behaviors of the resultant FGPE are not affected by bending up to 180°. The flexible supercapacitor device shows only a small capacitance loss of 18% after 1000 cycles of 135° bending.