line representation of electrochemical cells

https://doi.org/10.1351/goldbook.09067
Notation giving electrodes, electroactive substances, and other relevant information for an electrochemical cell. The notation starts and finishes with an electrode. Phase boundaries are denoted with a solid vertical bar \(|\), boundaries between miscible liquids by a vertical dashed bar \(¦\), and a liquid junction by double vertical dashed bars \(¦¦\).
Note: The potential difference of an electrochemical cell is measured between a metallic conductor attached to the right-hand electrode of the notation and an identical metallic conductor attached to the left-hand electrode.
Examples:
  1. \(\ce{Pt(s)}\:|\:\ce{H2(g)}\:|\:\ce{HCl(aq)}\:|\:\ce{AgCl(s)}\:|\:\ce{Ag(s)}\)
  2. \(\ce{Cu(s) | CuSO4(aq)\ ¦\ ZnSO4(aq) | Zn(s)}\)
  3. \(\ce{Cu(s) | CuSO4(aq)\ ¦¦\ KCl(aq, sat)\ ¦¦\ ZnSO4(aq) | Zn(s)}\)
Source:
PAC, 2020, 92, 641. 'Terminology of Electrochemical Methods of Analysis (IUPAC Recommendations 2019)' on page 649 (https://doi.org/10.1515/pac-2018-0109)