Influence of operating temperature on the activation efficiency of Li-ion cells with xLi2MnO3-(1-x)LiMn0.5Ni0.5O2 electrodes

In this study, the effect of operating temperature at 55 °C on xLi2MnO3-(1-x)LiMn0.5Ni0.5O2 electrodes during the charge/discharge process at different current densities was investigated. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used for structural and morphological analysis of the fabricated cathode materials, while charge-discharge curves and differential capacity were used to study the electrochemical behavior. Results confirm the formation of the structures with two phases associated with the components of the layered material. It was found that at 55 °C, a capacity higher than 357 mAh g-1 could be achieved at a voltage of 2.5-4.8 V vs. Li/Li+, which was larger than the capacity achieved at room temperature. At 55 °C, a change in valence could be observed during charging and discharging due to the change in the position of the peaks associated with Mn and Ni, highlighting cathodic material with x = 0.5 as the material that retains the layered structure at this temperature. This work confirms the good performance of electrodes made with this material at elevated temperatures and gives a better understanding of its electrochemical behavior

Use of pineapple waste as fuel in microbial fuel cell for the generation of bioelectricity

The excessive use of fossil sources for the generation of electrical energy and the increase in different organic wastes have caused great damage to the environment; these problems have promoted new ways of generating electricity in an eco-friendly manner using organic waste. In this sense, this research uses single-chamber microbial fuel cells with zinc and copper as electrodes and pineapple waste as fuel (substrate). Current and voltage peaks of 4.95667 ± 0.54775 mA and 0.99 ± 0.03 V were generated on days 16 and 20, respectively, with the substrate operating at an acid pH of 5.21 ± 0.18 and an electrical conductivity of 145.16 ± 9.86 mS/cm at two degrees Brix. Thus, it was also found that the internal resistance of the cells was 865.845 ± 4.726 Ω, and a maximum power density of 513.99 ± 6.54 mW/m2 was generated at a current density of 6.123 A/m2 , and the final FTIR spectrum showed a clear decrease in the initial transmittance peaks. Finally, from the biofilm formed on the anodic electrode, it was possible to molecularly identify the yeast Wickerhamomyces anomalus with 99.82% accuracy. In this way, this research provides a method that companies exporting and importing this fruit may use to generate electrical energy from its waste.Campus Trujill

Use of onion waste as fuel for the generation of bioelectricity

The enormous environmental problems that arise from organic waste have increased due to the significant population increase worldwide. Microbial fuel cells provide a novel solution for the use of waste as fuel for electricity generation. In this investigation, onion waste was used, and managedtogeneratemaximumpeaksof4.459±0.0608mAand0.991±0.02Vofcurrentandvoltage, respectively. The conductivity values increased rapidly to 179,987±2859 mS/cm, while the optimal pH in which the most significant current was generated was 6968 ± 0.286, and the ◦ Brix values decreased rapidly due to the degradation of organic matter. The microbial fuel cells showed a low internal resistance (154,389±5228 Ω), with a power density of 595.69±15.05 mW/cm2 at a current density of 6.02 A/cm2; these values are higher than those reported by other authors in the literature. The diffractogram spectra of the onion debris from FTIR show a decrease in the most intense peaks, compared to the initial ones with the final ones. It was possible to identify the species Pseudomona eruginosa, Acinetobacter bereziniae, Stenotrophomonas maltophilia, and Yarrowia lipolytica adhered to the anode electrode at the end of the monitoring using the molecular technique

Effect of x on the Electrochemical Performance of Two-Layered Cathode Materials xLi2MnO3–(1−x)LiNi0.5Mn0.5O2

In our study, the cathodic material xLi2MnO3–(1−x)LiNi0.5Mn0.5O2 was synthesized by means of the co-precipitation technique. The effect of x (proportion of components Li2MnO3 and LiNi0.5Mn0.5O2) on the structural, morphological, and electrochemical performance of the material was evaluated. Materials were structurally characterized using X-ray diffraction (XRD), and the morphological analysis was performed using the scanning electron microscopy (SEM) technique, while charge–discharge curves and differential capacity and impedance spectroscopy (EIS) were used to study the electrochemical behavior. The results confirm the formation of the structures with two phases corresponding to the rhombohedral space group R3m and the monoclinic space group C2/m, which was associated to the components of the layered material. Very dense agglomerations of particles between 10 and 20 µm were also observed. In addition, the increase in the proportion of the LiNi0.5Mn0.5O2 component affected the initial irreversible capacity and the Li2MnO3 layer’s activation and cycling performance, suggesting an optimal chemical ratio of the material’s component layers to ensure high energy density and long-term durability

Golden Berry Waste for Electricity Generation

The environmental problems caused by the excessive use of fossil fuels for electricity generation have led to the development of new technologies. Microbial fuel cells constitute a technology that uses organic sources for electricity generation. This research gives a novel means of using Golden Berry waste as fuel for electricity generation through microbial fuel cells made at low cost, achieving current and voltage peaks of 4.945 ± 0.150 mA and 1.03 ± 0.02 V, respectively. Conductivity values increased up to 148 ± 1 mS/cm and pH increased up to 8.04 ± 0.12 on the last day. The internal resistance of cells was 194.04 ± 0.0471 Ω, while power density was 62.5 ± 2 mW/cm2 at a current density of 0.049 A/cm2. Transmittance peaks of the Fourier-transform infrared (FTIR) spectrum showed a decrease when comparing the initial and final spectra, while the bacterium Stenotrophomonas maltophilia was molecularly identified with an identity percentage of 99.93%. The three cells connected in series managed to generate 2.90 V, enough to turn on a TV remote control. This research has great potential to be scalable if it is possible to increase the electrical parameters, generating great benefits for companies, farmers, and the population involved in the production and marketing of this fruit

Use of Banana Waste as a Source for Bioelectricity Generation

The large amounts of organic waste thrown into the garbage without any productivity, and the increase in the demand for electrical energy worldwide, has led to the search for new eco-friendly ways of generating electricity. Because of this, microbial fuel cells have begun to be used as a technology to generate bioelectricity. The main objective of this research was to generate bioelectricity through banana waste using a low-cost laboratory-scale method, achieving the generation of maximum currents and voltages of 3.71667 ± 0.05304 mA and 1.01 ± 0.017 V, with an optimal pH of 4.023 ± 0.064 and a maximum electrical conductivity of the substrate of 182.333 ± 3.51 µS/cm. The FTIR spectra of the initial and final substrate show a decrease in the peaks belonging to phenolic compounds, alkanes, and alkenes, mainly. The maximum power density was 5736.112 ± 12.62 mW/cm2 at a current density of 6.501 A/cm2 with a peak voltage of 1006.95 mV. The molecular analysis of the biofilm formed on the anode electrode identified the species Pseudomonas aeruginosa (100%), and Paenalcaligenes suwonensis (99.09%), Klebsiella oxytoca (99.39%) and Raoultella terrigena (99.8%), as the main electricity generators for this type of substrate. This research gives a second use to the fruit with benefits for farmers and companies dedicated to exporting and importing because they can reduce their expenses by using their own waste

Generation of bioelectricity from organic fruit waste

This research proposes an alternative for companies and farmers through the production of electricity using microbial fuel cells (MFCs) using waste from export products. Nine MFCs were manufactured with zinc and copper electrodes; and as substrates, pineapple, potato and tomato pulp wastes were used in the anode chamber, and residual sludge in the cathode chamber. It was observed that the MFCs with pineapple substrate generated higher values of the electrical parameters, resulting in voltage and current values of 0.3484 ± 0.003 V and 27.88 ± 0.23 mA, respectively. It was also observed that the maximum power density was 0.967 ± 0.059 W/cm2 at a current density of 0.04777 A/cm2 for the same substrate. Acid pH values were observed in the three samples, while the conductivity reached its maximum value on day 23 (69.47 ± 0.91 mS/cm) which declined until the last day of monitoring; the turbidity values increased abruptly after day 22 until the last day where a value of 200.3 ± 2.52 UNT was observed for the pineapple substrate. The scanning electron microscopy for the pineapple substrate MFC electrodes shows the formation of a porous biofilm on the zinc and copper electrodes. These results show that a new form of electricity production has been achieved by generating high voltage and current values, using low-cost materials

Sugar industry waste for bioelectricity generation

Microbial fuel cells are presented as the promise of technology to generate electricity by using organic waste. In this research, molasses waste from Laredo Agroindustrial Company was used as fuel, as well as graphite and zinc electrodes, managing to build low-cost cells. It was possible to generate voltage and current peaks of 0.389 ± 0.021 V and 1.179 ± 0.079 mA, respectively. The cells showed that acid pH levels and conductivity values were around 100 mS/cm during the period of the highest bioelectricity generation. The maximum power density was 3.76 ± 0.62 W/ cm2 for a current density of 247.55 mA/cm2, showing a peak voltage of 0.459 ± 0.52 V. The yeasts showed a logarithmic phase up to day 25 reflecting an increase in cell growth. Microbial fuel cells are projected to be the most viable solution for organic waste and clean energy generation problems

In Vitro Effect of Molasses Concentration, pH, and Time on Chromium Removal by Trichoderma spp. from the Effluents of a Peruvian Tannery

The effluents generated by the tannery industry have a high content of chromium and other toxic elements, representing a potential threat to ecosystems. An eco-friendly alternative to treat these effluents is the use of microorganisms, such as fungi, with the capacity to biosorb heavy metals. The present work aims to determine the effect of the molasses concentration, pH variation, and time on the removal of total chromium using the filamentous fungus Trichoderma spp. An experimental design was adopted using pH (4 and 6), concentrations of molasses (0.5 and 1%), and time (8 and 12 days) as independent variables. The Trichoderma inoculum was constant in all the treatments. The different treatments were evaluated after 0, 8, and 12 days by taking 50 mL of sample from each bioreactor. The chromium concentration was subsequently determined in each sample. The results show that treatment 3 (1% molasses and pH 4) showed higher chromium removal after both 8 and 12 days. The concentrations of total chromium decreased from 665 mg/mL to values of 568 mg/mL by day 8 and 486 mg/mL by day 12. These values are, however, still above the maximum threshold imposed by Peruvian law regarding the discharge of non-domestic effluents into the sewage system. The results show that Trichoderma spp. can increasingly remove chromium from the effluent with longer incubation periods. However, future studies are necessary to determine the mechanisms of chromium biosorption by the fungus and the influence of other physicochemical parameters

In Vitro Effect of Molasses Concentration, pH, and Time on Chromium Removal by Trichoderma spp. from the Effluents of a Peruvian Tannery

The effluents generated by the tannery industry have a high content of chromium and other toxic elements, representing a potential threat to ecosystems. An eco-friendly alternative to treat these effluents is the use of microorganisms, such as fungi, with the capacity to biosorb heavy metals. The present work aims to determine the effect of the molasses concentration, pH variation, and time on the removal of total chromium using the filamentous fungus Trichoderma spp. An experimental design was adopted using pH (4 and 6), concentrations of molasses (0.5 and 1%), and time (8 and 12 days) as independent variables. The Trichoderma inoculum was constant in all the treatments. The different treatments were evaluated after 0, 8, and 12 days by taking 50 mL of sample from each bioreactor. The chromium concentration was subsequently determined in each sample. The results show that treatment 3 (1% molasses and pH 4) showed higher chromium removal after both 8 and 12 days. The concentrations of total chromium decreased from 665 mg/mL to values of 568 mg/mL by day 8 and 486 mg/mL by day 12. These values are, however, still above the maximum threshold imposed by Peruvian law regarding the discharge of non-domestic effluents into the sewage system. The results show that Trichoderma spp. can increasingly remove chromium from the effluent with longer incubation periods. However, future studies are necessary to determine the mechanisms of chromium biosorption by the fungus and the influence of other physicochemical parameters