Process for the manufacture of contact strips for electrolyzers
In the case of a process for the manufacture of contact strips, in particular for electrolyzers (membrane cells), the objective is to provide a solution that allows to create a cheap but also extremely efficient method for the manufacture of such contact strips at a high electrical efficiency. This objective is achieved by applying the roll bonding method to attach a copper strip to a titanium strip.
1. A process for the manufacture of contact strip for membrane electrolyzers consisting of nickel, copper and titanium comprising:
attaching a copper strip to a titanium strip by roll bonding process to obtain a copper-titanium contact strip for membrane electrolyzers while destroying or removing oxide layers;
roll bonding a nickel strip to said copper-titanium strip to obtain a nickel-copper-titanium strip with the copper strip as an intermediate layer; and
providing only a single longitudinal groove in a central part of said nickel-copper-titanium contact strip by mechanical machining to remove the central part of said contact strip to form two contact webs and exposing a titanium surface of said titanium strip,
wherein the contact webs comprise nickel and copper; and
wherein in a first step of said roll boding process, a cold forming rate of 60 to 80% is performed, thereby obtaining a contact strip for membrane electrolyzers consisting of nickel, copper and titanium.
2. The process according to claim 1 wherein said titanium strip is an untreated titanium strip and said copper strip is a cleaned copper strip.
3. The process according to claim 1 wherein said titanium strip and/or said copper strip is subjected to brushing on the bonding side prior to said roll bonding.
4. The process according to claim 3 wherein said brushing is effected in the longitudinal direction to the rolling operation.
5. A method of establishing electrical contact between adjacent membrane electrolyzers, said method comprising:
obtaining a contact strip for membrane electrolyzers consisting of nickel, copper and titanium by attaching a copper strip to a titanium strip by a roll bonding process while destroying or removing oxide layers, roll bonding a nickel strip to said copper-titanium strip to obtain a nickel-copper-titanium strip with the copper strip as an intermediate layer, and providing only a single longitudinal groove in a central part of said nickel-copper-titanium contact strip by mechanical machining to remove the central part of said contact strip to form two contact webs and exposing a titanium surface of said titanium strip; and
establishing said electrical contact between adjacent membrane electrolyzers via said contact strip,
wherein the contact webs comprise copper and wherein in a first step of said roll bonding process, a cold forming rate of 60 to 80% is performed.
6. The method according to claim 5 wherein said titanium strip is an untreated titanium strip and said copper strip is a cleaned copper strip.
7. The method according to claim 5 wherein said titanium strip and/or said copper strip is subjected to brushing on the bonding side prior to said roll bonding.
8. The method according to claim 7 wherein said brushing is effected in the longitudinal direction to the rolling operation.
9. The method according to claim 5 wherein a longitudinal groove is provided in a central part of said contact strip to form two contact webs.