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Effect of Using Various Cathode Materials (Carbon Felt, Ni-Co, Cu-B, and Cu-Ag) on the Operation of Microbial Fuel Cell

Włodarczyk Paweł P., Włodarczyk Barbara

Civil and Environmental Engineering Reports

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2023

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Vol. 33, no. 4

95--105

EN

Wastewater has high potential as an energy source. Therefore, it is important to recover even the smallest part of this energy, e.g., in microbial fuel cells (MFCs). The obtained electricity production depends on the process rate of the electrodes. In MFC, the microorganisms are the catalyst of anode, and the cathode is usually made of carbon material. To increase the MFC efficiency it is necessary to search the new cathode materials. In this work, the electricity production from yeast wastewater in membrane-less microbial fuel cells with a carbon felt, Ni-Co, Cu-B, and Cu-Ag cathodes has been analyzed. In the first place, the measurements of the stationary potential of the electrodes (with Cu-Ag catalyst obtained by the electrochemical deposition technique) were performed. Next, the analysis of the electric energy production during the operation of the membrane-less microbial fuel cell (ML-MFC). The highest parameters were obtained for the Ni-Co and Cu-Ag catalysts. The cell voltage of 607 mV for Ni-Co and 605 mV for Cu-Ag was obtained. Additionally, the power of 4.29 mW for both cathodes - Ni-Co and Cu-Ag was obtained. Moreover, Ni-Co and Cu-Ag allow the shortest time of COD reduction. Based on the test results (with selected MFC design, wastewater, temperature, etc.), it can be concluded that of all the analyzed electrodes, Cu-Ag and Ni-Co electrodes have the best parameters for use as cathodes in ML-MFC. However, based on the results of this study, it can be concluded that all the tested electrodes can be used as cathode material in MFC.

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Ogniwa litowo-jonowe wysokiej mocy : przegląd materiałów katodowych

Urbanek K.

Wiadomości Chemiczne

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2018

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[Z] 72, 5-6

265--278

EN

Due to lack of practical energy sources – ones that are ecological, economic, portable and capable of being regenerated – storage is necessary in modern world for many areas of life to which people became accustomed. Development of many devices requires convenient electric power sources, often providing high currents and voltages, capable of ensuring large amounts of energy in short time. New technologies of lithium-ion cell batteries are a promising solution to this problem – current technologies are frequently inadequate – however they still require massive workloads in research, development, implementation to industry, and then to consumer market. Because of advancement in this area and evergrowing group of people interested in it is imperative to render an overview of the situation and knowledge of this topic. This article presents a review of most intensely studied cathode materials capable of providing high power, viable paths of improvement and short description of most important features of lithium-ion cells along with issues requiring solutions.

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Synthesis Of Fe Doped LiMn2O4 Cathode Materials For Li Battery By Solid State Reaction

Horata N., Hashizume T., Saiki A.

Archives of Metallurgy and Materials

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2015

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Vol. 60, iss. 2A

949--951

EN

LiFe0.1Mn1.9O4 is expected as a cathode material for the rechargeable lithium-ion batteries. LiMn2O4 has been received attention because this has advantages such as low cost and low toxicity compared with other cathode materials of LiCoO2 and LiNiO2. However, LiMn2O4 has some problems such as small capacity and no long life. LiMn2O4 is phase transformation at around human life temperature. One of the methods to overcome this problem is to stabilize the spinel structure by substituting Mn site ion in LiMn2O4 with transition metals (Al, Mg, Ti, Ni, Fe, etc.). LiFe0.1Mn1.9O4 spinel was synthesized from Li2CO3, Fe2O3 and MnO22 powder. The purpose of this study is to report the optimal condition of Fe doped LiFe0.1Mn1.9O4. Li2CO3, Fe2O3, and MnO2 mixture powder was heated up to 1173 K by TG-DTA. Li2CO3 was thermal decomposed, and CO2 gas evolved, and formed Li2O at about 800 K. LiFe0.1Mn1.9O4 was synthesized from a consecutive reaction Li2O, Fe2O3 and MnO2 at 723 ~ 1023 K. Active energy is calculated to 178 kJmol−1 at 723 ~ 1023 K. The X-ray powder diffraction pattern of the LiFe0.1Mn1.9O4 heated mixture powder at 1023 K for 32 h in air flow was observed.

PL

LiFe0.1Mn1.9O4 jest obiecującym materiałem katodowym do zastosowania w bateriach litowo-jonowych z możliwością wielokrotnego ładowania. LiMn2O4 cieszy się dużym zainteresowaniem z powodu niskiego kosztu otrzymywania oraz niskiej toksyczności w porównaniu z innymi materiałami katodowymi typu LiCoO2 and LiNiO2 czy LiNiO2. Jednak LiMn2O4 posiada również wady: niską pojemność i krótką żywotność. Dodatkowo, przemiana fazowa LiMn2O4 zachodzi w temperaturze pokojowej. Jedną z metod rozwiązania tego problemu jest stabilizacja struktury spinelu poprzez podstawienie jonu Mn w sieci LiMn2O4 metalami przejściowymi (Al, Mg, Ti, Ni, Fe, itp.). Spinel LiFe0.1Mn1.9O4 syntezowano z proszków Li2CO3, Fe2O3 i MnO22. Celem badań było znalezienie optymalnych warunków syntezy spinelu LiFe0.1Mn1.9O4 domieszkowanego Fe. Mieszaninę proszków Li2CO3, Fe2O3 i MnO2 poddano analizie TG-DTA. W temperaturze 800 K Li2CO3 uległ rozkładowi termicznemu, w wyniku czego powstało CO2 i Li2O. LiFe0.1Mn1.9O4 zsyntezowano w wyniku reakcji następczej pomiędzy Li2O, Fe2O3 i MnO2 w temperaturze 723 ~ 1023 K. Energię aktywacji oszacowano na 178 kJmol−1 w zakresie temperatur 723 ~ 1023 K. Przeprowadzono także analizę XRD proszku LiFe0.1Mn1.9O4 wygrzewanego w 1023 K przez 32 godz. w warunkach przepływu powietrza.

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Akumulatory litowe jako współczesne systemy magazynowania energii

Bakierska M., Chojnacka A.

Wiadomości Chemiczne

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2014

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[Z] 68, 9-10

856--871

EN

Due to the need for comprehensive management of energy resources, the storage of energy becomes an increasingly important issue. From the analysis of the advantages and drawbacks of all methods of energy storage, reversible electrochemical cells seem to be the most effective. Among them, rechargeable lithium batteries are characterized by high energy density (Fig. 1), high voltage and good cyclic stability [7]. Thus, they have been a dominant technology of energy storage systems for over a decade. It is expected that market demand for Li-Ion cells in the coming years will grow at a rapid rate, as a result of their widespread use inter alia in portable electronic devices such as mobile phones, smartphones, tablet PCs and laptops (Fig. 2) [9]. This article presents the characteristics of lithium batteries. The most commonly used cathode material in Li-Ion battery is layered cobalt oxide (130 mAh/g). However, it is expensive and toxic material, thus manganese-based compounds (LiMnO2, LiMn2O4), polyanionic olivine structured materials (LiFePO4) and silicates Li2MSiO4 (M = Mn, Co, Fe) gain an increasing interest. Due to the presence of two lithium ions in the structure of silicates, these materials have a high theoretical capacity, reaching about 300 mAh/g (Tab. 2) [1, 7–9, 11, 12]. Commercially used anode material is graphite (372 mAh/g). Nevertheless, scientists are still looking for new anode materials with a higher gravimetric capacity. Researches are primarily focused on modifications of the graphite or the use of lithium alloys with other elements (Sn, Al, Si) (Tab. 3) [1, 9, 12, 14, 15]. In the Lithium-Ion cells only non-aqueous solutions are used in the character of electrolytes. As a best material, the inorganic electrolyte lithium salts (such as LiBr, LiAsF6, LiPF6, LiBF4, etc.) soluble in organic solvents are used [1, 2, 7, 8]. However, the study on alternative solutions (polymer electrolytes) is very important. Continuous technological progress makes the research on improving the reversible electrochemical cells necessary to fulfill the expectations of users in order to improve the quality of their lives.

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Nowe materiały katodowe w elektrolizie odpadowego kwasu solnego

Wandachowicz K., Gnot W., Bodzińska M.

Przemysł Chemiczny

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2004

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T. 83, nr 7

335-339

PL

Jedynym racjonalnym sposobem utylizacji odpadowego kwasu solnego jest jego bezpośrednia elektroliza w celu uzyskania chloru i wodoru. Problem stanowi niedoskonałe tworzywo elektrodowe, jakim jest grafit. Zaproponowano stosowanie alternatywnych tworzyw na osnowie miedzi i srebra. Otrzymano następujące materiały elektrodowe: miedź z galwaniczną powłoką srebra Cu/Ag 70-120 μm, także aktywowaną galwaniczną powłoką Pt o grubości 1 μm; srebro z termicznymi powłokami: Ag/Pt, Ag/ (70% Pt + 30% Ir); Ag/(40% RuO2 + 60% TiO2) oraz lite srebro. Po przebadaniu ww. materiałów uznano, że trudne kryteria procesu elektrolizy kwasu solnego spełniają elektrody: Ag/Pt i Cu/Ag 120 μm + 1 μm Pt.

EN

Novel cathodes including (l) Cu coated with 70-120 μm Ag coatings, (II) electrodes l activated with 1 μm Pt, (III) Ag thermally coated with Pt or Pt/Rh or (4:6 w/w) RuO2-TiO2or (2:2:6 w/w) RuO2-lrO2-TiO2, and (IV) solid Ag, were examd. for morphology, phase compn. (after test electrolysis), corrosion resistance (potentiostatically), and hydrogen overpotential. In aq. 220-g/dm3 HCI, electrodes l (110 and 120 (μm Ag) and IV showed lin. corrosion coeffs. of 0.004,0.012 and 0.013 mm /year, resp.; III were least resistant. Electrodes II met the criteria for electrolysis of aq. HCI.