Neutral pH Gel Electrolytes for V2O5 center dot 0.5H(2)O-Based Energy Storage Devices

作者：Qian Aniu; Zhuo Kai; Kannan Padmanathan Karthick; Chung Chan Hwa^*

来源：ACS Applied Materials & Interfaces, 2016, 8(50): 34455-34463.

DOI：10.1021/acsami.6b12672

• gel electrolyte
• vanadium oxide hydrates
• electrochemistry
• cyclic stability
• hybrid supercapacitors

Gel electrolytes are considered to be promising candidates for the use in supercapacitors. It is worthy to systematically evaluate the internal electrochemical mechanisms with a variety of cations (poly(vinyl alcohol) (PVA)based Li+, Na+, and K+) toward redox-type electrode. Herein, we describe a quasi-solid-state PVA-KCl gel electrolyte for V2O5 center dot 0.5H(2)O-based redox-type capacitors, effectively avoiding electrochemical oxidation and structural breakdown of layered V2O5 center dot 0.5H(2)O during 10 000 charge-discharge cycles (98% capacitance retention at 400 mV s(-1)). With the gel electrolyte, symmetric V2O5 center dot 0.5H(2)O-reduced graphene oxide (V2O5 center dot 0.5H(2)O-rGO) devices exhibited a volumetric capacitance of 136 mF cm 3, which was much higher than that of 68 mF cm-3 for PVA-NaCl and 45 mF cm(-3) for PVA-LiCl. Additionally, hybrid full cells of activated carbon doth//V2O5 center dot 0.5H(2)O-rGO delivered an energy density of 102 mu Wh cm(-3) and a power density of 73.38 mW cm3 over a wide potential window of 2 V. The present study provides direct experimental evidence for the contribution of PVA-KCl gel electrolytes toward quick redox reactions for redox-type capacitors, which is also helpful for the development of neutral pH gel electrolytes for energy storage devices.

• 出版日期2016-12-21