пористая структура

The paper considers the most significant properties of moulding solutions based on a mixture of polyvinylidene fluoride and polystyrene for the process of capillary-free electrospinning nonwoven materials. It has been shown that the material obtained from the mixed solution of polyvinylidene fluoride and polystyrene in the ratio of components 0.75 : 0.25 is the largest porous, the diameter of the fibers is in the widest range from 0.14 to 2.8 μm, and branching of the fibers is observed.

The efficiency of oxygen ionization in a lead-acid mock-up was studied using a separator based on an absorptive glass mat (AGM) and polymer non-woven fibrous materials based on F-2M polyvinylidene fluoride and polystyrene. Fibrous material obtained by capillary-free electrospinning. The technological and structural characteristics of the polymer material are investigated. It was found that the use of a sandwich polymer/AGM/polymer separator significantly increases the efficiency of oxygen ionization.

The effect of carbon materials of two types was studied: multi-walled carbon nanotubes (“Art-nano” of the NSU “S” brand (TU BU 690654933.001.-2011)) and multilayer graphene (“Art-nano GT” (TU BU 691460594.004–2017), and modifications by treatment with ozone and dimethylformamide (manufacturer LLC Advanced Research and Technology, Belarus) on the structural characteristics, capacity and utilization of the active mass of the negative electrode of a lead-acid battery.

УДК 541.135

DOI:  https://doi.org/10.18500/1608-4039-2016-16-1-17-23

The influence of porous structure of the absorptive glass mats manufactured by «Hollingsworth&Vose» (thickness 2.8 mm) and BernardDumas» (thickness 3.0 mm), modified by impregnation with polymeric emulsions on the basis of polyvinylidene fluoride (KYNAR), polyvinylpyrrolidone copolymer with styrene (PVS) and polytetrafluoroethylene (Tf), on the efficiency of ionization of hydrogen in lead-acid battery mock-ups. The use of polymer modified emulsions separators from absorbtive glass mat allows to increase the ionization rate of hydrogen on lead-dioxide electrode.

The most important structural and physicomechanical properties of absorbent glass mat separators «Hollingswoth and Vose», «Bernard Dumas», «BMSK AT Nippon» intended for lead-acid battery (LAB) are studied. It is shown that on pore size distribution strong influence puts the enclosed pressure: at compression 50 kPa there is a considerable reduction of the size of a pore. However for the separation material «BMSK AT Nippon» the share of pores with radius from 5 to 10 microns is much higher, than for the separation materials «Hollingswoth and Vose» and «Bernard Dumas». Studying of process of oxygen absorption on negative an electrode in the LAB models showed that most effectively process of absorption of oxygen occurs in the LAB models to the separation material «BMSK AT Nippon».

A study of the porous structure and discharge characteristics of electrochemically impregnated nickel oxide electrodes based on nickel- ized graphitized felt«Voilocarb-22» is conducted. It is shown that the developed technology of nickel oxide electrodes fabrication that involves such operations as nickel plating of the substrate, electrochemical impregnation, electrode formation and pressing allows forming polydisperse structured electrode active material with pore sizes ranging from 0.01 pm to 100 pm. The electrochemical tests have shown that the mockup batteries with newly-developed nickel oxide electrodes based on nickelized carbon/graphite felt have surpassed all requirements of the international standard IEC 62259:2007.

In this review electrochemical and structural data for the electrodes made of certain of perspective materials for supercapacitors are considered. These electrodes were made on the basis of high-dispersed carbon materials. The following materials were used: singlelayer and multilayer carbon nanotubes; reduced oxide of graphene; the carbide type activated carbon; polyacrilonitrile fibers treated by carbonization and activation; the activated carbon fibrous material; the activated carbon cloth; a composite of polyporphirine on carbon black; polyporhine of magnesium, electrodeposited on carbon paper; and a polyaniline composite with the singlelayer nanotubes, electrodeposited on carbon paper. The short review of techniques of synthesis of these electrode materials is presented. Comparison of capactance characteristics of these electrodes for the purpose of the recommendation of their use in certain types of electrochemical supercapacitors is carried out.

In this article was studied pressure influence in the electrode block of the model of the lead-acid accumulator on the most important physical properties (a specific surface, pore size distribution, compression properties, speed of capillary lifting of electrolyte) of absorbent glass mat separators of the trademarks «Hollingsworth» (USA) and "Bernard Dumas"(France) and on efficiency of an oxygen cycle. It is shown that the highest compression properties separators with a high specific surface (7-10 m²/g) possess. The increase of pressure in the electrode block conducts to pores size redistribution towards decrease in a share of a pore with a radius of 10-15 microns and increase in a share of smaller pore with radius of 1-5 microns. Observed reduction of a share of a large pore explains decrease in height and speed of lifting of electrolyte with higher pressure in the electrode block. The increase of pressure in the electrode block to 50 kPa leads to decrease oxygen ionization rate on a lead electrode.