Electrochemical Performance of AlÕMnO2 Dry Cells: An Alternative to Lechlanche Dry Cells

Aluminum-MnO2 �Al/MnO2� dry cells of “D” size configuration are investigated as an alternative to the Lechlanche dry cell, where aluminum is replaced for zinc as the anode, MnO2 as the cathode, and a mixture of aluminum chloride/ammonium chloride/chromium chloride as the electrolyte. Investigations regarding the optimization of conducting material, electrolyte composition, and electrochemical performance of the cell at different temperature and current drains �100, 200, and 400 mA� are carried out. Internal resistance and storage life of the fabricated aluminum dry cells are also evaluated. The results suggest that Al/MnO2 dry cells exhibit a superior performance than their Zn counterpar

Sol-Gel Synthesis of 5 V LiCuxMn2−xO4 as a Cathode Material for Lithium Rechargeable Batteries

Spinel LiCuxMn2−xO4 0.025 x 0.1 has been synthesized using oxalic acid as the chelating agent using a sol-gel method to obtain submicrometer-sized particles, good surface morphology, homogeneity, agglomeration, and high crystallinity involving short heating time. X-ray diffraction XRD, scanning electron microscopy SEM, Fourier transform infrared spectroscopy, and thermogravimetric and differential thermal analysis were carried out for the physical characterization of the synthesized powder. The XRD patterns of LiCuxMn2−xO4 show the single-phase spinel product, which is in good agreement with the JCPDS card 35-782. SEM images show that the particles, on the average, are of 50 nm in size and are present as agglomerated clusters at all dopant levels. Electrochemical cycling studies of the compound were carried out between 3 and 5 V to understand the redox behavior of Cu2+ ions. The charge–discharge cycling studies of spinel material with Cu stoichiometry of x = 0.1 calcined at 850°C exhibit an initial discharge capacity of 130 mAh g−1 and stabilized at 120 mAh g−1

Synthesis, Characterization, and Electrochemical Properties of LiCrxNiyMn2−x−yO4 Spinels as Cathode Material for 5 V Lithium Battery

Sol–gel assisted spinel LiCrxNiyMn2−x−yO4 0 x 0.4 and 0 y 0.4 has been synthesized. The thermal study of the precursor was carried out by thermogravimetric and differential thermal analyses. Furthermore, the material has been subjected to X-ray diffraction, scanning electron microscopy, Fourier transform IR spectroscopy analysis, X-ray photoelectron spectroscopy, cyclic voltammetry studies, and electrochemical charge–discharge studies. The X-ray diffraction of LiCrxNiyMn2−x−yO4 matches well with the Joint Committee on Powder Diffraction Standard card no. 35-782, confirming the formation of a single-phase spinel. Charge–discharge studies were carried out between 3 and 5 V to understand the electrochemical behavior of the undoped and doped spinels. LiCr0.25Ni0.25Mn1.5O4 calcined at 850°C possesses a particle size of around 70 nm and exhibits an initial discharge capacity of 105 mAh g−1 stabilizing at 98 mAh g−1 over the investigated 20 cycles. However, maleic acid derived LiCr0.25Ni0.25Mn1.5O4 delivers a stable higher discharge capacity of 115 mAh g−1 over the investigated 20 cycles and is a promising 5 V cathode material

Performance of meta-nitroaniline in magnesium reserve batteries

IV/-IAh Magnesium (Mg)/m-nitro aniline (MNA) cells have been constructed using Mg anode and MNA cathode. The cells were investigated for their performance behaviour at diffcrent current densities and with various aqueous magnesium electrolytes viz: magnesium chloride [MgCI2], Magnesium perchlorate IMg(CI0,l)2] and magnesium bromide [MgBr2], after initial standardization of the cathode mix. The discharge behaviour of the above magnesium cells are discussed in terms of cathodic efficiency of MNA. Cyclic voltammetric studies of MNA cells were carried out which indicates the irreversible natun: of the depolarizer

Electrochemical Behavior of LiM0.25Ni0.25Mn1.5O4 as 5 V Cathode Materials for Lithium Rechargeable Batteries

Glycine-assisted sol-gel–synthesized multiple-doped spinels, LiM0.25Ni0.25Mn1.5O4 M = Cr, Fe, and Co have been studied as 5 V cathode materials. The sol-gel technique provides homogeneity, high purity, lower processing temperature, controlled particle size, and morphology. The synthesized samples were subjected to physical characterization studies, viz., thermogravimetric and differential thermal analysis, X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and electrochemical charge–discharge studies. Galvanostatic charge–discharge studies of the samples reveal that LiFe0.25Ni0.25Mn1.5O4 using glycine as a chelating agent delivers a stable capacity of 120 mAh g−1 even after 20 cycles when cycled between 3 and 5 V

Cerium and zinc: Dual-doped LiMn2O4 spinels as cathode material for use in lithium rechargeable batteries

Pristine spinel lithiummanganese oxide (LiMn2O4) and zinc- and cerium-doped lithiummanganese oxide [LiZnxCeyMn2−x−yO4 (x = 0.01–0.10; y = 0.10–0.01)] are synthesized for the first time via the sol–gel route using p-amino benzoic acid as a chelating agent to obtain micron-sized particles and enhanced electrochemical performance. The sol–gel route offers shorter heating time, better homogeneity and control over stoichiometry. The resulting spinel product is characterized through various methods such as thermogravimetic and differential thermal analysis (TG/DTA), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX) and electrochemical galvanostatic cycling studies. Charge–discharge studies of LiMn2O4 samples heated at 850 ◦C exhibit a discharge capacity of 122mAhg−1 and a corresponding 99% coulombic efficiency in the 1st cycle. The discharge capacity and cycling performance of LiZn0.01Ce0.01Mn1.98O4 is found to be superior (124mAhg−1), with a low capacity fade (0.1mAhg−1 cycle−1) over the investigated 10 cycles

Synthesis of lithium vanadate and its characterisation

In view of h~b specific capacity, possibility of lithium uptake to 3.0 Li/mol with respect to cycleability, structural stability, high rate capability (due to high diffusion of lithium) and deep dischllrgeability below 1.6 V lithium vanadate is preferred to V,013 In lithium secondary cells. To have materials of less particle size, sol-gel synthesis coupled with proper dehydration processes are followed to synthesize LiV308 and it is characterized by XRD and FfIR analysis. Results are presented in this communication

Microwave synthesis of novel high voltage (4.6 V) high capacity LiCuxCo1−xO2±ı cathode material for lithium rechargeable cells

Layered LiCuxCo1−xO2±ı (0.0≤x≤0.3) has been synthesized using microwave method. This method possesses many advantages such as homogeneity of final product and shorter reaction time compared to other conventional methods. The structure and electrochemical properties of the synthesized materials are characterized through various methods such as XRD, SEM, FTIR, XPS and galvanostatic charge/discharge studies. The XRD patterns of LiCuxCo1−xO2±ı confirm the formation of single-phase layered material. SEM images show that the particles are agglomerated and the average particle size decreases with increasing amount of copper. Electrochemical cycling studies are carried out between 2.7 and 4.6V using 1M LiPF6 in 1:1 EC/DEC as electrolyte. The charge/discharge cycling studies of layered material with LiCu0.2Co0.8O19 exhibit an average discharge capacity of∼150mAhg−1 over the investigated 50 cycle

High-Performing LiMgxCuyCo1−x−yO2 Cathode Material for Lithium Rechargeable Batteries

Sustainable power requirements of multifarious portable electronic applications demand the development of high energy and high power density cathode materials for lithium ion batteries. This paper reports a method for rapid synthesis of a cobalt based layered cathode material doped with mixed dopants Cu and Mg. The cathode material exhibits ordered layered structure and delivers discharge capacity of ∼200 mA h g−1 at 0.2C rate with high capacity retention of 88% over the investigated 100 cycle