Cell voltage in the electrolytic stack

Reasons for the increase or decrease of the voltage in the electrolytic cell chamber

During the operation of the electrolytic cell, the cell voltage is usually monitored manually or online in real time, because the cell voltage can directly reflect the internal conditions of the electrolytic cell. So, what situations will cause abnormal cell voltage?

1. Water replenishment is not timely or uniform, and the electrolyte concentration is unstable, which affects the ion migration during the electrolysis process and causes the chamber voltage to fluctuate.
2. There is alkali leakage in the system, which reduces the total amount of potassium hydroxide in the tank. After water replenishment, the concentration decreases, causing voltage fluctuations. This is because the alkali leakage is not discovered, such as dripping into the ditch.
3. Damage to the diaphragm will lead to direct contact between the electrodes on both sides, causing a short circuit, resulting in a decrease in the chamber voltage and a decrease in gas purity.
4. The diaphragm is contaminated or blocked by impurities, which causes ion transmission to be blocked and also causes the chamber voltage to fluctuate.
5. Metal impurities accumulate in the alkali solution pipeline or hydrogen and oxygen pipeline inside the electrolytic cell, causing the current to short-circuit inside the flow channel, which is also the reason for the voltage drop.
6. The alkali solution channel entering the small chamber is blocked, and the alkali solution circulation in the small chamber is not smooth, resulting in a reduction in alkali solution, exposing the electrodes and diaphragms. This will increase the current density and voltage. If it is a local blockage, this phenomenon will disappear after parking for a period of time and then driving again, but the voltage will increase again after running for a period of time.
7. The hydrogen / oxygen passage out of the small chamber is blocked, and the generated hydrogen and oxygen cannot be discharged in time, resulting in a reduction in the effective electrolysis area in the small chamber and an increase in the voltage in the small chamber.
8. The cooling system fails and cannot effectively control the temperature of the electrolytic cell. For example, uneven cooling water flow or abnormal coolant temperature may cause partial overheating or overcooling of the #electrolytic cell, resulting in fluctuations in the cell voltage. When the ambient temperature changes greatly, it will also affect the thermal balance of the electrolytic cell and thus affect the cell voltage.
9. The active substances on the electrode surface fall off or age, or the electrode is contaminated, which leads to the decline of the electrocatalytic performance of the electrode, affects the efficiency of electron transfer, and causes voltage fluctuations.
10.  the possibility that the instrument for measuring voltage is damaged