LOWER PLASTIC, BATTERY, BATTERY MODULE AND ELECTRIC DEVICE

Provided are a plastic component, a battery, a battery module, and an electric device. The plastic component (10) includes a body having a first side surface (1) and a second side surface (2) facing away from the first side surface (1). The first side surface (1) has a buffer recess (11). The second side surface (2) has a connection piece recess (21). The plastic component (10) satisfying at least one of: condition 1): 1 mm≤c-e≤2 mm and 1 mm≤c-f≤2 mm, where c is a thickness of the body, f is a depth of the buffer recess (11), e is a depth of the connection piece recess (21); and condition 2): 1 mm≤p≤2 mm, p= (a-t*g-r*d) /n, where g is a length of the connection piece recess (21), t is a number of the connection piece recesses (21), r is a number of the buffer recesses (11), d is a length of the buffer recess (11), a is a length of the body, and p is a thickness of each of n side walls arranged in a length direction of the body.