Potassium-Ion Battery Electrolytic Solution Additive, Potassium-Ion Battery Electrolytic Solution, Potassium-Ion Battery, Potassium-Ion Capacitor Electrolytic Solution Additive, Potassium-Ion Capacitor Electrolytic Solution, Potassium-Ion Capacitor, and Negative Electrode

Provided is a potassium-ion battery or capacitor electrolytic solution additive, which is a compound represented by Formula (1), Formula (1A), or Formula (1B). In Formula (1), Formula (1A), and Formula (1B), R each independently represents NRR, an alkyl group, a cycloalkyl group, a heterocyclic group, an aryl group, or a heteroaryl group, each of Rand Rindependently represents a hydrogen atom, an alkyl group, an aryl group, or, a heteroaryl group, and Rand Rmay be bonded to form a ring structure. Provided that, in R bonded to a sulfur atom, in a case in which R is a heterocyclic group, the sulfur atom is bonded to an atom other than a nitrogen atom.