Electrochromic display element, optical filter, lens unit, and imaging device

An electrochromic display element comprising:

• a pair of electrodes;
• and
• an electrochromic layer disposed between the electrodes, the electrochromic layer containing:
• a solvent;
• a supporting electrolyte:
• an anodic electrochromic molecule comprising a triarylamine derivative;
• and
• a cathodic electrochromic molecule comprising a viologen derivative,
• wherein concentrations of the triarylamine derivative and the viologen derivative in the electrochromic layer are each 4 mM or more, and
• wherein the viologen derivative comprises a compound represented by the following general formula (5):
• where each of R1 and R2 independently represents an alkyl or aryl group having 1 to 10 carbon atoms which may have a substituent;
• each of n and m independently represents 0 or an integer of from 1 to 10;
• and X represents a monovalent anion selected from the group consisting of ClO4 ion (ClO4-), PF6 ion (PF6-), BF4 ion (BF4-), CF3SO3 ion (OTf-), (FSO2)2N ion (FSI-), (CF3SO2)2N ion (TFSI-), or B(CN)4 ion (TCB-).