A comprehensive review of pre-lithiation/sodiation additives for Li-ion and Na-ion batteries

Lithium/Sodium-ion batteries(LIB/SIB)have attracted enormous attention as a promising electrochemical energy storage system due to their high energy density and long cycle life.One of the major hurdles is the initial irreversible capacity loss during the first few cycles owing to forming the solid electrolyte interphase layer(SEI).This process consumes a profusion of lithium/sodium,which reduces the overall energy density and cycle life.Thus,a suitable approach to compensate for the irreversible capacity loss must be developed to improve the energy density and cycle life.Pre-lithiation/sodiation is a widely accepted process to compensate for the irreversible capacity loss during the initial cycles.Various strategies such as physical,chemical,and electrochemical pre-lithiation/sodiation have been explored;however,these approaches add an extra step to the current manufacturing process.Alternative to these strategies,pre-lithiation/sodiation additives have attracted enormous attention due to their easy adaptability and compatibility with the current battery manufacturing process.In this review,we consolidate recent developments and emphasize the importance of using pre-lithiation/sodiation additives(anode and cathode)to overcome the irreversible capacity loss during the initial cycles in lithium/sodium-ion batteries.This review also addresses the technical and scientific challenges of using pre-lithiation/sodiation additives and offers the insights to boost the energy density and cycle life with their possible commercial exploration.The most important prerequisites for designing effective pre-lithiation/sodiation additives have been explored and the future directions have been discussed.

Synthesis and Characterisations of TiO₂Coated Multiwalled Carbon Nanotubes/Graphene/Polyaniline Nanocomposite for Supercapacitor Applications

Nowadays with ever increasing demand of energy, developing of alternative power sources is an important issue all over the world. In this respect we have prepared nanocomposites based on metal oxide (titanium oxide) coated multiwalled carbon nanotubes (MWCNTs)/polyaniline (PANI) with graphene and without graphene and studied their electrochemical performance. The formation of the polymer in the nanocomposites was confirmed by the Fourier Transform Infrared Spectroscopy (FTIR) study. The morphological characterisations were carried out by the Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM). To characterize the prepared nanocomposites electrode, a cyclic voltammetry test for measuring specific capacitance, and an impedance test were conducted. The highest value of specific capacitance obtained for the TiO2 coated MWCNTs/PANI nanocomposite was 443.57 F/g at 2 mV/s scan rate. Upon addition of graphene nanosheet to the TiO2 coated MWCNTs in a weight ratio of (9:1) the specific capacitance value increased to 666.3 F/g at the same scan rate, also resulting in an increase in energy density and power density.

Enhanced photocatalytic degradation of 4-nitrophenol using polyacrylamide assisted Ce-doped YMnO_(3) nanoparticles

This research article mainly reports on the precise structural,optical,and photocatalytic properties of cerium(Ce)-substituted yttrium manganite(YMnO_(3))nanoparticles synthesized by the polyacrylamide gel method.The characteristics of YMnO_(3)were investigated by the substitution of Ce into the Y site at various molar percentages.The Raman and X-ray diffraction(XRD)analyses confirmed the pure phase of hexagonal YMnO_(3),supported by the Rietveld refinement.The microstructural studies indicate inhomogeneous and irregular particle distribution.The X-ray photoelectron spectroscopy(XPS)results show the presence of two ionic states of Mn and Ce along with Y^(3+)state and oxygen vacancies.Extensive optical exploration using photoluminescence(PL)spectroscopy and UV-Vis-NIR analysis indicates that the intensity of absorption peak increases in the visible region,while the bandgap decreases from 1.42 to1.30 eV with the Ce ion doping(5 mol%-15 mol%).Photocatalytic properties of the polycrystalline nanoparticles were investigated by degradation of the pollutant 4-nitrophenol.The process of amplified photocatalysis process was elucidated by the lowered bandgap and rate of charge carrier recombination.It can be conjugated from this study that the synthesized nanoparticles may be employed as highly efficient(92.8%)visible light-triggered photocatalysts in a variety of real-world applications.