Electrochemical energy storage devices

An electrochromic device comprising:

• a cathodic material covalently attached to, or confined within, a first polymer matrix;
• and
• an anodic compound polymerized into a second polymer matrix;
• wherein:
• the cathodic material is a viologen;
• the anodic compound is a phenazine, a bisphenazine, a phenothiazine, a bisphenothiazine, a triphenodithiazine, a bis(triphenodithiazine), a carbazole, a indolocarbazole, a biscarbazole, or a ferrocene;
• the electrochromic device exhibits a high transmission state at short circuit and a low transmission state upon application of an electric potential;
• the high transmission state is at least 5 times greater than the low transmission state;
• and
• the electrochromic device is configured to maintain a transmission percentage within 20% of the low transmission state for at least 5 hours at open circuit after application of a potential sufficient to reach to the low transmissions state.