Electrode, use thereof, battery, and process for producing an electrode

1 . A process for producing an electrode having at least one porous silicon layer and a copper layer on the at least one porous silicon layer, the process comprising:

etching a silicon substrate for forming at least one porous silicon layer; and

depositing a copper layer on the at least one porous silicon layer;

wherein the electrode is configured for a lithium-ion battery; and

etching the silicon substrate to form a multilayer system made up of a plurality of porous silicon layers that differ from one another in a quality of the porous silicon layers selected from the group consisting of porosities, pore sizes, and pore shapes, and wherein the at least one porous silicon layer is one of the plurality of porous silicon layers of the multilayer system.

2 . The process according to claim 1 , wherein etching the silicon substrate comprises etching the silicon substrate wet-chemically.

3 . The process according to claim 2 , which comprises etching the silicon substrate in a continuous process.

4 . The process according to claim 1 , wherein etching the silicon substrate comprises etching the silicon substrate on one side.

5 . The process according to claim 1 , wherein etching the silicon substrate comprises etching the silicon substrate electrochemically, by:

transporting the silicon substrate along a direction of transport through a plurality of treatment tanks arranged one after the other in the direction of transport, each of the treatment tanks being filled with an etching medium and each having an electrode arranged therein;

during transport through the treatment tanks, contacting the silicon substrate on a substrate underside with the etching medium present in the respective treatment tank; and

wherein a polarity of the electrodes arranged in the treatment tanks alternates in the direction of transport.

6 . The process according to claim 1 , which comprises depositing the copper layer in a two-stage process including:

a first deposition step wherein a first portion of the copper layer is deposited on the at least one porous silicon layer by galvanic displacement; and

a second deposition step wherein a second portion of the copper layer is deposited on the first portion of the copper layer by electrochemical deposition.

7 . The process according to claim 1 , which comprises:

a first deposition step in which a nickel layer is deposited on the at least one porous silicon layer by electrochemical deposition; and

a second deposition step in which the copper layer is deposited on the nickel layer by electrochemical deposition.

8 . The process according to claim 1 , which comprises:

forming the multilayer system with the porous silicon layer of the multilayer system having a greatest porosity immediately adjoining an unporosified portion of the silicon substrate.

9 . The process according to claim 1 , which comprises removing the at least one porous silicon layer together with the copper layer from an unporosified portion of the silicon substrate.

10 . The process according to claim 9 , wherein removing the at least one porous silicon layer together with the copper layer comprises subjecting the silicon substrate to a thermal treatment.

11 . The process according to claim 10 , which comprises treating the silicon substrate in a continuous oven.

12 . The process according to claim 9 , which comprises intercalating lithium in the at least one porous silicon layer after the at least one porous silicon layer has been removed together with the copper layer from the unporosified portion of the silicon substrate.

13 . The process according to claim 1 , which comprises integrating the electrode as an anode in a battery.

14 . An electrode having at least one porous silicon layer and a copper layer on the at least one porous silicon layer, comprising:

an etched silicon substrate forming at least one porous silicon layer;

a copper layer deposited on the at least one porous silicon layer;

the electrode being configured for a lithium-ion battery; and

a plurality of porous silicon layers forming a multilayer system arranged on top of one another and differing from one another in a quality selected from the group consisting of porosities, pore sizes, and pore shapes, and wherein said at least one porous silicon layer is one of said plurality of porous silicon layers of said multilayer system.

15 . The electrode according to claim 14 , wherein the electrode is configured as a foil.

16 . The electrode according to claim 14 , wherein the electrode is configured as a rollable film.

17 . The electrode according to claim 14 , which comprises lithium intercalated in said at least one porous silicon layer.

18 . The electrode according to claim 14 , configured for a lithium-ion battery.