Structural and electrochemical characteristics of o-LiMnO2-MWCNTs nanocomposites

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. •Synthesis of orthorhombic phase of LiMnO2 by sol gel.•Composite formation of o-LiMnO2 with varied concentrations of functionalized CNTs.•Raman spectroscopy of composites to determine stress created during thecomposite formation process.•An insight into charge transfer process from electrochemical impedancespectroscopy (ionic conductivity through electrode).•Effect of CNTs concentration on the redox reactions.•Determination of optimal CNTs concentration.