Enhancing Conductivity of Polymer Electrolyte by Magnetic Heating

PEO Electrolyte

PEO (Polyethylene Oxide) electrolyte is a polymer material widely studied as a solid electrolyte in lithium-ion batteries and other electrochemical energy storage devices. PEO offers high ionic conductivity and facilitates lithium-ion movement through its flexible polymer structure. However, its low ionic conductivity at room temperature poses a significant limitation for practical applications.

Electrolyte Improvement Using Magnetic Fields

This study explores a method to enhance the ionic conductivity of PEO electrolyte by adding magnetic powder (Fe3O4, FeC) and utilizing inductive heating via magnetic fields. The core objective of this research is to determine whether magnetic materials within the PEO electrolyte generate heat under an alternating current (AC) magnetic field, thereby increasing the electrolyte temperature and improving lithium-ion mobility.

For this study, experimental equipment was designed and fabricated. A coil and power supply capable of applying an AC magnetic field were developed, and electrolyte samples were prepared to measure temperature variations under magnetic field application. Additionally, Electrochemical Impedance Spectroscopy (EIS) and Arrhenius plots were used to analyze changes in ionic conductivity.

Experimental Results

: Improved Conductivity and Unexpected Limitations

Experimental results demonstrated that magnetic heating effectively increased the electrolyte temperature, leading to a significant improvement in ionic conductivity. The EIS test and Arrhenius plots confirmed that temperature elevation contributed to enhanced ionic conductivity.

However, when integrated into a battery cell and subjected to charge-discharge tests, an issue was observed where the magnetic material absorbed lithium ions due to its electrochemical potential difference, causing lithium loss. FTIR and Raman Spectroscopy analysis confirmed this phenomenon, ultimately leading to battery performance degradation and failure to achieve the study's primary goal.

Research Significance and Future Directions

Despite these challenges, this study provided deeper insights into methods for improving the ionic conductivity of PEO-based electrolytes, interactions between battery electrolytes and electrodes, and the utilization of electrochemical performance measurement devices such as EIS, FTIR, Raman Spectroscopy, and SEM. Future research should explore surface modification of magnetic materials to reduce reactivity with lithium ions or investigate alternative heating materials to mitigate lithium loss.

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