An end cover assembly, an energy storage apparatus, and an electricity-consumption device are provided in the disclosure. The end cover assembly includes a top cover, a lower plastic member, a sealing member, and a terminal post. The lower plastic member is fixed to the top cover and defines a hollow hole and a first flow passage. The hollow hole extends through the lower plastic member in a direction from the lower plastic member to the top cover. One end of the first flow passage is in communication with a side wall of the hollow hole, and another end of the first flow passage is in communication with an outside. The sealing member includes a first sealing portion disposed in the hollow hole. The terminal post has a flange portion.