Salt bridge

[3] It also maintains electrical neutrality within the internal circuit and stabilizes the junction potential between the solutions in the half-cells.

[6] The electrolyte solution usually comprises a combination of cations, such as ammonium and potassium, and anions, including chloride and nitrate, which have similar mobility.

Traditionally, concentrated aqueous potassium chloride (KCl) solution has been used for decades to neutralize the liquid-junction potential.

[1] Yet, the effectiveness of this salt bridge decreases as the ionic strength of the sample solution increases.

This is because ionic liquids do not mix with water (they are immiscible), rendering them suitable as salt bridges for aqueous solutions.

[3] Normally, glass frits, a porous material, cover the ends of the tube or the electrolyte is often gelified with agar-agar to help prevent the intermixing of fluids that might otherwise occur.

[9] A porous junction serves as a salt bridge between the two half-cells of reference and electrolyte solutions.

[9] Despite being fragile, charcoal facilitates efficient ion transfer due to its highly porous structure.

An electrochemical cell (resembling a Daniell cell ) with a filter paper salt bridge. The paper has been soaked with a Potassium nitrate solution.
The labeled salt bridge shows the U-shaped glass tube used as a salt bridge.
Charcoal (black box at the bottom of the cell) acts as a salt bridge to allow ion transfer.