Magnetic field assisted high capacity durable Li-ion battery using magnetic α-Fe₂O₃ nanoparticles decorated expired...

We have synthesized a novel ferromagnetic material by coating α-Fe₂O₃ nanoparticles with N-doped carbon matrix using a simple combustion method. Expired paracetamol drugs are used as nitrogen and carbon source. This α-Fe₂O₃/NC shows ferromagnetic property due to the incorporation of oxygen defects. When used as the Li-ion battery anode, α-Fe₂O₃/NC shows higher capacity compared to commercial α-Fe₂O₃ due to the occurrence of both intercalation and conversion reaction. Further, application of magnetic field at the anode of the freshly assembled cell at the first charge-discharge cycle, results in ~two-fold enhancement in specific capacity. For the cycled cell also, increase in the capacity from 80 mAh. g^-1 to 150 mAh. g^-1 at 5 A. g^-1 is observed during the application of magnetic field at the 501^st charging cycle. This improved performance is attributed to the field-dependent enhancement of diffusion and convection due to the magnetohydrodynamic effect. Further, application of the magnetic field at 1001^st, 1501^st and 1751^st charging cycles shows improved LIB performance. We can show that not only the magnetic field, magnetic properties of the anode α-Fe₂O₃/NC also play a crucial role in influencing the battery performance. Moreover, utilization of expired drug helps in dramatically reducing pollution caused by its disposal.