Stimuli‐responsive 3radialene radical anions dimerize reversibly in a controlled manner. An unprecedented tristate switching mechanism can be achieved by changing the solvent environment, temperature, or salinity of the solution. This allows the radical to be toggled between the free radical, a π‐dimer, and a σ‐dimer, which exhibit dramatically different optical, magnetic, and redox properties. The addition of salt to the radialene catholyte solution in an aqueous redox flow battery (RFB) converts the σ‐dimer to the π‐dimer and increases the electrochemical reversibility and stability of the charged species, which are advantageous for galvanostatic charge–discharge studies at neutral pH. More information can be found in the Research Article by Arthur H. Winter, C. Bejger, and co‐workers (DOI: 10.1002/chem.202302829). Illustration by Frank A. Martinez.