Comparison of Gel battery and AGM battery - 2
How the battery works
Whether it is a valve-regulated sealed lead-acid battery using GLASS FIBER SEPARATOR (hereinafter referred to as AGM sealed lead-acid battery) or a valve-regulated sealed lead-acid battery using colloidal electrolyte (hereinafter referred to as colloidal-sealed lead-acid battery), they all use the principle of cathode absorption to seal the battery.
When the battery is charged, the positive electrode will evolve oxygen and the negative electrode will evolve hydrogen. The oxygen evolution of the positive electrode starts when the charge of the positive electrode reaches 70%. The precipitated oxygen reaches the negative electrode and reacts with the negative electrode as follows to achieve the purpose of absorption by the negative electrode. The hydrogen evolution of the negative electrode should start when the charge reaches 90%, coupled with the reduction of oxygen on the negative electrode and the increase of the hydrogen overpotential of the negative electrode itself, so as to avoid a large number of hydrogen evolution reactions.
For AGM sealed lead-acid batteries, although most of the electrolyte of the battery is kept in the AGM SEPARATOR, 10% of the pores of the separator must not enter the electrolyte. The oxygen generated by the positive electrode reaches the negative electrode through this part of the pores and is absorbed by the negative electrode.
For colloidal-sealed lead-acid batteries, the silicone gel in the battery is a three-dimensional porous network structure composed of SiQ particles as a skeleton, which hides the electrolyte. After the silica sol injected into the battery turns into a gel, the skeleton will further shrink, so that cracks appear in the gel to penetrate between the positive and negative plates, providing a channel for the oxygen precipitated from the positive electrode to reach the negative electrode.
It can be seen that the sealing principle of the two batteries is the same, the difference lies in the way of "fixing" the electrolyte and the way of supplying oxygen to the negative electrode channel.
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