A valve , comprising: a valve body configured to be mounted on a box body of a battery , the valve body being provided with a pressure relief port and a medium injection port configured to be connected to a fire-fighting device; a closing member connected to the valve body and closing the pressure relief port and the medium injection port , the closing member being configured to open the pressure relief port and the medium injection port when a pressure or a temperature inside the box body reaches a threshold, so as to relieve the pressure inside the box body and allow the fire-fighting device to inject a fire-fighting medium into the box body through the medium injection port ; wherein the valve body comprises a body and a mounting member mounted on the body , the pressure relief port being provided on the body , and the closing member being connected to the body , and the medium injection port being provided on the mounting member ; wherein the pressure relief port comprises a plurality of inlets distributed circumferentially at intervals and a plurality of outlets distributed circumferentially at intervals, and the plurality of outlets are located at peripheries of the plurality of inlets ; the inlet is configured to be connected with the medium injection port when the closing member opens the pressure relief port and the medium injection port , and the outlet is configured for exhausting gas in the box body when the fire-fighting medium enters the box body through the medium injection port and the inlet in sequence; and the mounting member is provided with an exhaust port independent of the medium injection port , when the closing member opens the pressure relief port and the medium injection port , the gas can be exhausted out of the box body through the outlet and the exhaust port in sequence. a valve body configured to be mounted on a box body of a battery , the valve body being provided with a pressure relief port and a medium injection port configured to be connected to a fire-fighting device; a closing member connected to the valve body and closing the pressure relief port and the medium injection port , the closing member being configured to open the pressure relief port and the medium injection port when a pressure or a temperature inside the box body reaches a threshold, so as to relieve the pressure inside the box body and allow the fire-fighting device to inject a fire-fighting medium into the box body through the medium injection port ; wherein the valve body comprises a body and a mounting member mounted on the body , the pressure relief port being provided on the body , and the closing member being connected to the body , and the medium injection port being provided on the mounting member ; wherein the pressure relief port comprises a plurality of inlets distributed circumferentially at intervals and a plurality of outlets distributed circumferentially at intervals, and the plurality of outlets are located at peripheries of the plurality of inlets ; the inlet is configured to be connected with the medium injection port when the closing member opens the pressure relief port and the medium injection port , and the outlet is configured for exhausting gas in the box body when the fire-fighting medium enters the box body through the medium injection port and the inlet in sequence; and the mounting member is provided with an exhaust port independent of the medium injection port , when the closing member opens the pressure relief port and the medium injection port , the gas can be exhausted out of the box body through the outlet and the exhaust port in sequence. <EOS>