Electrochromic devices can dynamically manage buildings' optical and thermal properties without mechanical force. Substantial progress has been made in both fundamental electrochemistry and commercialization. However, it is still challenging to realize large mid-infrared (mid-IR) emissivity tuning contrast and long-term durability. In addition, for building applications, the usage of costly and flammable electrolytes will limit the scalability and create safety concerns. (52) Indeed, creating energyefficient, durable, economical, and electrically switchable building envelopes for radiative thermal management requires a rational systematic design of electrochemical redox reactions, electrolyte, and electrode materials.