Neutral pH Gel Electrolytes for V2O5·0.5H2O-Based Energy Storage Devices
Aniu Qian1, Kai Zhuo1, Padmanathan Karthick Kannan1
1School of Chemical Engineering, Sungkyunkwan University , Suwon 16419, Republic of Korea.
ACS Applied Materials & Interfaces
|December 22, 2016
Summary
A novel quasi-solid-state poly(vinyl alcohol) (PVA)-KCl gel electrolyte enhances V2O5·0.5H2O redox-type supercapacitors. This electrolyte improves stability and performance, offering a promising avenue for advanced energy storage devices.
Area of Science:
- Materials Science
- Electrochemistry
- Energy Storage
Background:
- Gel electrolytes are promising for supercapacitors.
- Systematic evaluation of cations (Li+, Na+, K+) in poly(vinyl alcohol) (PVA)-based electrolytes is needed for redox-type electrodes.
- Layered V2O5·0.5H2O is a potential electrode material but suffers from oxidation and breakdown.
Purpose of the Study:
- To develop and evaluate a quasi-solid-state PVA-KCl gel electrolyte for V2O5·0.5H2O-based redox-type capacitors.
- To investigate the electrochemical mechanisms and performance improvements offered by different cations (K+, Na+, Li+) in PVA-based gel electrolytes.
- To assess the stability and energy storage capabilities of supercapacitors utilizing the developed gel electrolyte.
Main Methods:
- Fabrication of quasi-solid-state PVA-KCl gel electrolyte.
- Construction of symmetric V2O5·0.5H2O-reduced graphene oxide (V2O5·0.5H2O-rGO) supercapacitors and hybrid full cells.
- Electrochemical characterization including charge-discharge cycling, cyclic voltammetry, and galvanostatic charge-discharge measurements.
- Comparison of performance with PVA-NaCl and PVA-LiCl electrolytes.
Main Results:
- The PVA-KCl gel electrolyte demonstrated excellent stability for V2O5·0.5H2O, preventing oxidation and breakdown over 10,000 cycles with 98% capacitance retention at 400 mV s-1.
- Symmetric V2O5·0.5H2O-rGO devices with PVA-KCl achieved a high volumetric capacitance of 136 mF cm-3, significantly outperforming PVA-NaCl (68 mF cm-3) and PVA-LiCl (45 mF cm-3).
- Hybrid full cells delivered an energy density of 102 μWh cm-3 and a power density of 73.38 mW cm-3 over a 2 V potential window.
Conclusions:
- PVA-KCl gel electrolytes significantly enhance the electrochemical performance and stability of V2O5·0.5H2O-based redox-type capacitors.
- The study provides experimental evidence for the contribution of PVA-KCl gel electrolytes to rapid redox reactions in capacitors.
- This work supports the development of neutral pH gel electrolytes for advanced energy storage applications.
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