Structural and electrochemical characteristics of o-LiMnO2-MWCNTs nanocomposites

Abstract This paper reports the structural and electrochemical studies of the composite made up of orthorhombic LiMnO2 (o-LiMnO2) and oxidized MWCNTs in various percentages where CNTs replaced the carbon black (CB) as an additive material. X-ray diffraction (XRD) patterns confirmed the formation of distorted orthorhombic phase of the space group with Pmnm. Raman spectra showed eight visible Raman modes of LiMnO2. A blue shift (~7 cm−1) in the Raman mode associated with Mn–O bond of composite materials was observed, which was due to mechanical stresses. The EIS measurement indicated the low charge transfer resistance (105 kΩ) for o-LiMnO2/CNTs composites compared to o-LiMnO2/CB composites (195 kΩ). The CV results confirmed the reduction in potential gap between redox peaks with the addition of CNTs, which decreased from 2.02 V to 1.76 V. CNTs provided a network of conducting channel for Li ions as well as resulted in reduction of polarization of redox potentials.