Lithium insertion into manganese dioxide electrode in MnO_2/Zn aqueous battery. Part II. Comparison of the behavior of EMD and battery grade MnO_2 in Zn|MnO_2| aqueous LiOH electrolyte

摘要

A comparative study of the cathodic behavior of electrolytic manganese dioxide (EMD) and chemically prepared battery grade manganese dioxide (BGM) in Zn|MnO_2| aqueous lithium hydroxide (LiOH) cells has been carried out. The X-ray diffraction (XRD), infrared spectra (IR), thermo gravimetric analysis (TGA) and scanning electron microscope (SEM) investigations showed that the two materials had different phase compositions, water content and particle sizes. The cells with BGM had a higher open circuit voltage (OCV) and discharged at higher voltages as compared to those with EMD. The discharge capacity of BGM was lower compared to that of EMD. On discharge both the materials produced same phase i.e. lithium intercalated manganese dioxide (Li_xMnO_2). This was also confirmed through X-ray photoelectron spectroscopy (XPS) investigation of the discharged products.