Sealing principle of valve control type sealed lead-acid batteries -
Valve control type sealed lead-acid batteries is done by using negative absorption principle oxygen compound cycle to achieve sealing effect.
Because of negative hydrogen evolution later than the positive oxygen evolution, and according to the special cell structure, so late lead battery cathode can't exhalation hydrogen, which can absorb the positive of oxygen, which is negative absorption principle.
And according to this principle to achieve sealing.
Lead battery to 70% when the anode will begin to oxygen precipitation, negative charge to reach 90% of the time to begin to oxygen precipitation.
Valve control type sealed lead-acid batteries have special battery structure, oxygen can be well absorbed by the cathode.
The cathode in the absorption of oxygen method has two, one is to react with the cathode active material of lead, another method is to produce electrochemical reaction after the cathode for electronic.
All belong to the composite oxygen cycle reaction.
As shown in figure 5 -
The cathode besides absorb oxygen, and negative charge will happen reaction.
Oxygen transfer valve control type sealed lead-acid batteries in the late charge, the anode will oxygen precipitation formation overpressure, the cathode absorption of oxygen to produce negative pressure, under the action of pressure difference between positive and negative electrode, the oxygen can pass to the cathode gas diffusion channel migration.
Negative to fully absorb the positive oxygen precipitation, will have to transfer to the cathode.
Oxygen is generally divided into two ways within the cell transmission: one kind is dissolved in the electrolyte in the way, that is to say by liquid phase diffusion to the cathode surface;
Another is the bullishness of gas phase diffusion to the surface of the cathode.
The better diffusion process of oxygen, oxygen from the positive to the negative migration, the more the amount of absorbed by the cathode so batteries can be through the water in the large current does not make a battery loss.
Oxygen to the cathode diffusion in the form of gases, oxygen diffusion velocity is much larger than the speed of by dissolved oxygen in liquid phase diffusion.
To absorb oxygen faster, so the valve control type sealed lead-acid batteries provide oxygen in the gas phase diffusion channel.
In order to in the valve control type sealed lead-acid batteries provide oxygen diffusion channels, so the cell structure of the special.
It is depleted electrolyte structure, make super fine glass fiber membrane cuhk channel is not being filled with electrolyte, as oxygen diffusion channels, oxygen can be smoothly spread to the cathode.
Two is tight assembly, make closely contact with the diaphragm plate surface, the electrolyte can be fully wet plate, the second is to ensure that oxygen diaphragm channel spread to the cathode, without oxygen along the plate up overflow.