END COVER ASSEMBLY, BATTERY CELL, AND ENERGY-STORAGE APPARATUS

An end cover assembly (100), a battery cell (200), and an energy-storage apparatus (300) are provided. The end cover assembly (100) includes an upper cover (10), an upper plastic member (20), a terminal post (30), and a supporting member (40). The upper cover (10) has a first surface (11) and a second surface (12). The upper cover (10) further defines a through hole (13). The upper plastic member (20) partially passing through the through hole (13). The upper plastic member (20) defines a penetrating hole (21) and a mounting hole (22), and the upper plastic member (20) has a first orthographic projection on the first surface (11). The terminal post (30) includes a flange portion (31) and a penetrating portion (32). The flange portion (31) has a second orthographic projection on the first surface (11). The supporting member (40) has a third orthographic projection on the first surface (11). The third orthographic projection partially overlaps with the first orthographic projection and partially overlaps with the second orthographic projection.