Magnetoresistive Nanocomposites for Electrochemical Energy Storage

摘要

Conductive polymers and their homogeneous nanocomposites incorporated with both magnetic and non-magnetic nanofillers have been reported exhibiting unique giant magnetoresistance (GMR, a large resistance change upon applying a magnetic field) phenomena. Inspired by the enhanced electrical conductivity in the material with a negative GMR, GMR was first innovatively introduced to the electrochemical capacitors (ECs), which are in urgent demand for storing energies from sustainable and renewable energy sources due to the depletion of fossil fuels and concerns over climate changes. To utilize the synergies of electrostatic and Lorentz forces for the purpose of enhancing the power densities of the conductive polymers and their nanocomposites with high theoretical specific capacitances is new and has rarely been reported. Herein, lab made nanocomposites from conductive polymers including magnetic magnetite/polypyrrole (PPy) and non-magnetic poly(p-phenylene-2,6-benzobisoxazole) fibers coated with PANI have been prepared and tested for electrochemical energy storage under small magnetic fields. The improved power densities have been observed and are explained considering the magnetohydrodynamics (MHD, the enhanced movement of the ions under both the electric and magnetic fields) and GMR effects.