Method for producing a cyclically stable silicon anode for secondary batteries, and silicon anode for secondary batteries

A method for producing a silicon anode for secondary batteries, comprising:

• a. providing a monocrystalline silicon wafer with (100)-oriented front and rear flat sides;
• b. contacting the rear flat side of the wafer with a flat first electrode;
• c. introducing the front flat side of the wafer into an etching bath having a hydrofluoric acid-containing electrolyte and a second electrode;
• d. electrochemically etching mesopores of at least 4 micrometers pore depth into the front flat side of the silicon wafer by establishing a predetermined etching current density to produce a mesoporous layer while generating a porosity between 40% and 80% in the mesoporous layer;
• e. generating a microporous release layer below the mesoporous layer by increasing the etching current density;
• f. placing the etched wafer in an electroplating bath;
• g. electrodepositing an elemental metal into the etched mesopores to a predetermined pore depth less than 2 micrometers;
• h. depositing a metal layer onto the etched front flat side of the wafer while producing electrically conductive and mechanically adherent contacts of the metal layer with the elemental metal in the mesopores;
• and
• i. lifting off the metal layer and the mesoporous, monocrystalline, (100)-oriented silicon layer partially filled with elemental metal in the mesopores while mechanically destroying the microporous release layer.