Raw cellulose/polyvinyl alcohol blending separators prepared by phase inversion for high-performance supercapacitors
Yingqi Heng1, Tianqi Xie1, Xiyang Wang2,3
1Wood Industry Research Institute, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, People's Republic of China.
Nanotechnology
|November 18, 2020
Summary
Biodegradable cellulose/polyvinyl alcohol films offer a green alternative for supercapacitor separators. The CP-20 film demonstrated superior mechanical strength, wettability, and porosity, leading to enhanced supercapacitor performance and stability.
Area of Science:
- Materials Science
- Electrochemistry
- Green Chemistry
Background:
- Supercapacitors are crucial energy storage devices, demanding high-performance, sustainable separator materials.
- Current separators often lack biodegradability or optimal electrochemical properties, hindering green energy development.
Purpose of the Study:
- To develop and evaluate novel biodegradable cellulose-based separators for supercapacitors.
- To investigate the structure-property relationships of cellulose/polyvinyl alcohol (CP) films.
- To assess the electrochemical performance and stability of supercapacitors utilizing these novel separators.
Main Methods:
- Fabrication of regenerated porous cellulose/polyvinyl alcohol (CP) films via blending and phase inversion.
- Characterization using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD).
- Evaluation of physical properties: mechanical strength, wettability, porosity, and electrolyte uptake.
- Electrochemical testing: Electrochemical Impedance Spectroscopy (EIS), Cyclic Voltammetry (CV), and Galvanostatic Charge-Discharge (GCD).
Main Results:
- CP-20 film exhibited optimal properties: 28.02 MPa mechanical strength, 79.06° wettability, 59.69% porosity, and 281.26 wt% electrolyte uptake.
- Supercapacitors using CP-20 (SC-20) showed the lowest equivalent series resistance (0.57 Ω) and highest areal capacitance (1.98 F cm⁻²).
- SC-20 demonstrated superior energy density (28.24 Wh kg⁻¹), power density (6.04 kW kg⁻¹), and excellent cycling stability (86.81% retention after 4000 cycles).
Conclusions:
- Regenerated porous cellulose/polyvinyl alcohol films are promising biodegradable separators for high-performance supercapacitors.
- The CP-20 film offers a balanced combination of physical and electrochemical properties.
- These findings contribute to the advancement of sustainable energy storage technologies.
