porous structure

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.

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.