Ionic liquid and nanoparticle based magnetic electrolytes: Design, preparation, and electrochemical stability characterization

In this work, ionic liquid (IL) and nanoparticle (NP) based magnetic electrolytes are developed for the first time. The electrochemical stability of electrolyte is a crucial property for utilization in solar cells and batteries. The electrochemical stability behavior of the samples of pure ILs, ILs + NPs, ILs + NPs + iodide redox (I3−/I−), and ILs + H2O is investigated. It is shown that there is no significant electrochemical reaction in the pure ILs sample when direct current (DC) voltage ranging from 2 V to 40 V is applied. The results suggest that pure ILs have good electrochemical stability as electrolytes under DC voltage as high as 40 V. NPs are utilized in order to improve the performance of ILs as electrolytes. It is found that the presence of NPs does not influence the electrochemical stability of the electrolytes under the DC electrical field. Moreover, I3−/I− is added to form samples of ILs + NPs + I3−/I−. It is shown that the presence of I3−/I− reduces the electrochemical stability of most of the IL + NP + I3−/I− electrolytes utilized in this work. The presence of water can also reduce the electrochemical stability of the IL based electrolytes. Furthermore, the effect of a magnetic field on the NP concentration gradient in the samples of ILs + NPs and ILs + NPs + I3−/I− is investigated. It is shown that there is a NP concentration gradient in the samples when an external magnetic field is applied. This discovery is useful when utilizing the IL and NP based magnetic electrolytes in solar cells and batteries. Finally, electrodes of the samples of BmimPF6 + Fe2O3 NPs, and BmimPF6 + Fe2O3 NPs + I3−/I− after electrophoresis deposition experiments are compared. The findings in this work can enhance the development of utilization of IL and NP based magnetic electrolytes in solar cells and batteries.