Magnetic Nanomaterials for Energy Storage Applications

Nanomaterials are found interesting in the area of electrochemical supercapacitor applications due to attracting physical and chemical characteristics. Especially the magnetic nanomaterials are in high demand as an electrode material for electrochemical supercapacitor applications due to the recent progress made on the electrochemical supercapacitor characteristics with an external applied magnetic field. The external magnetic field influences the capacitive performances of the magnetic electrode materials, depending on the magnetic characteristics of the magnetic nanoparticles. Magnetic nanoparticles with moderate saturation magnetization resulting the enhancement in the capacitive performance, whereas the nanoparticles with very less saturation magnetization are not sufficient to give the response to the external magnetic field and not enhancing the capacitive performance respective to the applied magnetic field. Instead, the capacitive performance reduces with the applied external magnetic field due to the increase of magnetoresistance of the magnetic nanoparticles. Here we discussed the key parameters such as the magnetic characteristics of the magnetic nanoparticles, the fraction of magnetic nanoparticles in the magnetic nanocomposites and the external applied magnetic field strength to tune or to enhance the capacitive performance of the electrochemical supercapacitor. Also, the synthesis methods to obtain pure magnetic nanoparticle and the magnetic composite formation is discussed as the synthesis process is important to get the magnetic nanomaterials with higher saturation magnetization. This chapter provides a brief idea about the synthesis and surface modification of magnetic nanoparticles and their utilization for the magnetic field-assisted electrochemical supercapacitor applications.