Chemical Changes During Cycling on the Surface of the Negative Electrode of Lead-Acid Batteries

2021 ◽  
Vol 105 (1) ◽  
pp. 143-149
Author(s):  
Jan Smejkal ◽  
Ladislav Chladil

Our contribution deals with the study of surface processes and chemical composition on the surface of the negative electrode of a lead-acid battery during cycling at different speeds. Thin electrodes were created for the measurements. The negative electrode was analyzed at six SOC states (100 %, 80 %, 60 %, 40 %, 20 % and 0 % SOC). The proportion of individual elements on the surface of the negative electrode during cycling at 0.2 C, 0.3 C and 0.5 C was evaluated. Chemical changes occurring on the surface of the negative electrode during cycling of the lead-acid battery were measured using an X-ray diffractometer, and the presence of individual chemical elements on the surface of the electrode was evaluated using the Rietveld method. At higher cycling speeds, an increase in the material was observed, which did not convert during cycling, and higher cycling speeds caused a more significant material conversion near the negative electrode collector.

2021 ◽  
Vol 105 (1) ◽  
pp. 119-134
Author(s):  
Jana Zimáková ◽  
Petr Baca ◽  
Martin Langer ◽  
Tomáš Binar

This work deals with lead-acid batteries, their properties and individual types that are available on the market. The temperature dependences of the battery parameters at different ambient temperatures and at different discharging and charging modes are measured. 6 batteries are tested at different charging currents, which provides information about their behavior both during discharge and at the time of charging. During the experiments, testing is not only performed at room temperature, but the batteries are also exposed to high temperatures up to 75 °C.


2021 ◽  
Vol 74 (8) ◽  
pp. 1869-1875
Author(s):  
Svitlana P. Yarova ◽  
Iryna I. Zabolotna ◽  
Olena S. Genzytska ◽  
Andrii A. Komlev

The aim: Is to define dentine chemical composition of intact teeth and those with wedge-shaped defects followed by the analysis of revealed differences. Materials and methods: Longitudinal sections of 22 clinically removed teeth (12 – clinically intact ones, 10 – with wedge-shaped defects) from both jaws were studied in patients aged between 25-54 years. JSM-6490 LV focused beam electron microscope (scanning) with system of energy-dispersive X-ray microanalysis INCA Penta FETх3 was used. The chemical composition of 148 dentine areas in the incisal region (tubercle), equator, cervical area has been determined as a percentage of the weight amounts of carbon, oxygen, calcium, phosphorus, sodium, magnesium, sulfur, chlorine, zinc, potassium, aluminum. Results: Dentine chemical composition of teeth with wedge-shaped defects differed from those of intact teeth by significantly lower content: sodium, chlorine and calcium – in the incisal region (tubercle); sodium, magnesium − at the equator; sodium, chlorine and calcium – in the cervical region (p≤0.05). In the sample groups with cervical pathology there was more sulfur and oxygen in the incisal region (tubercle), phosphorus and zinc – at the equator, carbon and potassium – in the cervical region (p≤0.05). Conclusions: Differences in the chemical composition of intact teeth and teeth with wedge-shaped defects, the presence of correlation between the studied chemical elements confirm the role of macro- and microelements in the pathogenesis of non-carious cervical lesions.


2005 ◽  
Vol 3 (1) ◽  
pp. 665-668 ◽  
Author(s):  
Akiya Kozawa ◽  
Shigeyuki Minami ◽  
Yoshitaka Suzuki ◽  
Satoshi Iwata ◽  
Shoichiro Ikeda ◽  
...  

2020 ◽  
Vol 5 (8) ◽  
pp. 2469-2475
Author(s):  
S. Arun ◽  
C. Arul ◽  
S. Mithin Kumar ◽  
Uday Venkat Kiran ◽  
Sundar Mayavan

2009 ◽  
Vol 24 (4) ◽  
pp. 351-361 ◽  
Author(s):  
James A. Kaduk

The crystal structure of the mullite in a commercial material was refined by the Rietveld method using laboratory X-ray powder diffraction data. In this one refinement, most of the common challenges—including variable stoichiometry (partially occupied sites), multiple impurity phases, amorphous material, constraints, restraints, correlation, anisotropic profiles, microabsorption, and contamination during grinding—are encountered and the thought processes during the refinement are described step-by-step. Interpretation of the refinements includes bulk chemical analysis, chemical composition of the mullite, assessment of the geometry, bond valence sums, the displacement coefficients, crystallite size and microstrain, comparison to similar structures to assess chemical reasonableness, and the nature of the amorphous phase.


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