The present invention relates to a precursor of a negative electrode compartment for rechargeable metal-air batteries, comprising a rigid casing (1), at least one solid electrolyte membrane (2), a protective covering (5), completely covering the inside face of the solid electrolyte membrane (2), a metallic current collector (3) applied against the inside face of the protective covering (5), preferably also a block (4) of elastic material applied against the current collector and essentially filling the entire internal space defined by the walls of the rigid casing and the solid electrolyte (2), and a flexible electronic conductor (6) passing in a sealed manner through one of the walls of the rigid casing. The present invention also relates to a negative electrode compartment having a rigid casing obtained from said precursor and to a battery containing such a negative electrode compartment.