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Development in high-rate electrode materials capable of storing vast amounts of charge in a short duration to decrease charging time and increase power in lithium-ion batteries is an important challenge to address. Here, we introduce a synthesis strategy with a series of composition-controlled NMC cathodes, including LiNi0.2Mn0.6Co0.2O2(NMC262), LiNi0.3Mn0.5Co0.2O2(NMC352), and LiNi0.4Mn0.4Co0.2O2(NMC442). A very high-rate performance was achieved for Mn-rich LiNi0.2Mn0.6Co0.2O2 (NMC262). It has a very high initial discharge capacity of 285 mAh g−1 when charged to 4.7 V at a current of 20 mA g−1 and retains the capacity of 201 mAh g−1 after 100 cycles. It also exhibits an excellent rate capability of 138, and 114 mAh g−1 even at rates of 10 and 15 C (1 C = 240 mA g−1). The high discharge capacities and excellent rate capabilities of Mn-rich LiNi0.2Mn0.6Co0.2O2 cathodes could be ascribed to their structural stability, controlled particle size, high surface area, and suppressed phase transformation from layered to spinel phases, due to low cation mixing and the higher oxidation state of manganese. The cathodic and anodic diffusion coefficient of the NMC262 electrode was determined to be around 4.76 × 10−10 cm2 s−1 and 2.1 × 10−10 cm2 s−1, respectively.

The synthesis technique that can be used to accelerate the discovery of materials for various energy conversion and storage applications is presented. Specifically, this technique allows a rapid and controlled synthesis of mixed metal oxide particles using plasma oxidation of liquid droplets containing mixed metal precursors. The conventional wet chemical methods for synthesis of multimetal oxide solid solutions often require time-consuming high pressure and temperature processes, and so the challenge is to develop rapid and scalable techniques with precise compositional control. The concept is demonstrated by synthesizing binary and ternary transition metal oxide solid solutions with control over entire composition range using metal precursor solution droplets oxidized using atmospheric oxygen plasma. The results show the selective formation of metastable spinel and the rocksalt solid solution phases with compositions over the entire range by tuning the metal precursor composition. The synthesized manganese doped nickel ferrite nanoparticles, NiMn z Fe2−z O4 (0 ≤ z ≤ 1), exhibits considerable electrocatalytic activity toward oxygen evolution reaction, achieving an overpotential of 0.39 V at a benchmarking current density of 10 mA/cm2 for a low manganese content of z = 0.20.

The kinetics of n-butane dehydrogenation over CrO x VO x /MCM-41 catalyst was studied. The models were developed based on the catalyst tests carried out in a packed bed reactor at reaction temperatures varied from 525 to 575 °C under atmospheric pressure. The dehydrogenation of n-butane mainly gives butene isomers (over 90%), 1,3-butadiene and cracked products consisting of methane, ethane, ethene and propene. Based on the experimental observations, power law type models were formulated and parameters were estimated by fitting the experimental data implemented in MATLAB. The activation energy for the formation of butenes (96.2 kJ mol −1 ) was found to be considerably less than the activation energy for the formation of the undesirable cracked products (130.4 kJ mol −1 ).

The kinetics of n-butane dehydrogenation over CrOxVOx/MCM-41 catalyst was studied. The models were developed based on the catalyst tests carried out in a packed bed reactor at reaction temperatures varied from 525 to 575 °C under atmospheric pressure. The dehydrogenation of n-butane mainly gives butene isomers (over 90%), 1,3-butadiene and cracked products consisting of methane, ethane, ethene and propene. Based on the experimental observations, power law type models were formulated and parameters were estimated by fitting the experimental data implemented in MATLAB. The activation energy for the formation of butenes (96.2 kJ mol-1) was found to be considerably less than the activation energy for the formation of the undesirable cracked products (130.4 kJ mol-1).

The kinetics of n-butane dehydrogenation over CrOxVOx/MCM-41 catalyst was studied. The models were developed based on the catalyst tests carried out in a packed bed reactor at reaction temperatures varied from 525 to 575 degree C under atmospheric pressure. The dehydrogenation of n-butane mainly gives butene isomers (over 90%), 1,3-butadiene and cracked products consisting of methane, ethane, ethene and propene. Based on the experimental observations, power law type models were formulated and parameters were estimated by fitting the experimental data implemented in MATLAB. The activation energy for the formation of butenes (96.2 kJ mol-1) was found to be considerably less than the activation energy for the formation of the undesirable cracked products (130.4 kJ mol-1).

The study investigates the simple dehydrogenation of n-butane over mono (Cr or V) and bimetal (Cr-V) loaded MCM-41 catalysts. Wet impregnation technique was used, where the metal content maintained around 4wt.%. The unique properties of bimetal supported catalysts were evaluated by means of XRD, N2 adsorption, pyridine FT-IR, Raman spectroscopy, SEM-EDX, temperature programmed analysis (H2-TPR, NH3-TPD, CO2-TPD). The catalytic evaluation shows that Cr content of 1.2wt% and V content of 2.8wt% over MCM-41 designated as 1.2Cr2.8V/M-41 exhibited the highest butane conversion of 20.1% and butenes selectivity of 88.5% at 600 °C. In the presence of CO2, the stability of 1.2Cr2.8V/M-41catalyst was quite improved. The improved performance of bimetal catalysts can be correlated to synergetic effect of uniformly dispersed Cr-V-O mixed oxides over MCM-41, high reducibility and surface acidity. Oxidative dehydrogenation of n-butane was tested using CO2 as a mild oxidant over bimetallic Cr-V supported catalysts (MCM-41, ZSM-5, MCM-22 and mesoZSM-5). The metal content of Cr and V was maintained around 1.2wt.% and 2.8wt.% for the catalytic test in packed bed reactor at different temperatures (525–600°C) for 180 min. 1.2Cr2.8V/MCM-41 and 1.2Cr2.8V/ZSM-5 exhibited maximum conversion of 14 % and 13.1%, respectively at 10 min and 600 °C. Significantly, high butenes selectivity was observed over MCM-41 (86.27%) than ZSM-5 support (58.1%). The mesoporousity in ZSM-5 had a negative impact on conversion level (7.1%) but improved the butenes selectivity slightly. 1.2Cr2.8V/M-22 showed the highest cracking ability leading to overall reduced butenes selectivity (57.9%). The study shows that over all catalysts, n-butane conversion is independent of CO2 conversion. 1.2Cr2.8V/M-22 showed highest CO2 conversion in the range 2.35–2.2% between 525–550°C. The kinetics of n-butane dehydrogenation over 1.2Cr2.8V/M-41 catalyst was studied. The models were developed based on the catalyst tests carried out in a fixed bed reactor at reaction temperature varied from 525–575°C. Based on the experimental observations, power law type models were formulated and parameters were estimated by fitting the experimental data implemented in MATLAB.