Battery cell, battery, electric apparatus, and manufacturing method and device of battery cell

A method for manufacturing a battery cell, comprising:

• providing a housing, the housing having an accommodating cavity and an opening communicating with the accommodating cavity;
• providing an electrode assembly and loading the electrode assembly into the accommodating cavity of the housing;
• providing a cover assembly and sealing the opening with the cover assembly, wherein the cover assembly and the housing together form a casing, the casing is provided with an exhaust mechanism, the exhaust mechanism comprises a connecting component and a breathable component, the connecting component is configured to connect the casing, the breathable component is configured to discharge gas to outside of the casing when gas pressure inside the casing reaches a threshold;
• and
• injecting an electrolyte into the accommodating cavity so that specific effective ventilating area A of the breathable component, conductivity S of the electrolyte, and specific gas containment space V satisfy 20 mm2*mS/cm*ml<AS/V<165 mm2*mS/cm*ml, in which the specific gas containment space V is equal to a ratio of a remaining value of volume of the accommodating cavity minus volume of the electrolyte and volume of the electrode assembly to capacity of the electrode assembly, and the specific effective ventilating area A of the breathable component is a ratio of an effective ventilating area of the breathable component to the capacity of the electrode assembly,
• wherein the specific effective ventilating area A of the breathable component is greater than or equal to 0.15 mm2/Ah and less than or equal to 1.5 mm2/Ah;
• wherein the conductivity S of the electrolyte is greater than or equal to 8.5 mS/cm and less than or equal to 11 mS/cm;
• and
• wherein the specific gas containment space V is greater than or equal to 0.1 ml/Ah and less than or equal to 0.4 ml/Ah.