How nice that you have turned to WeFugees with your question.
In the first three years of your marriage, your stay here in Germany is tied to your wife or your marriage. After that, you can apply for a "separate" residence title (§31 Residence Act) or also a so-called settlement permit (permanent residence). This means that even if you and your wife separate, you can still apply for a residence title. The following conditions must be met.
The following requirements apply for the settlement permit:
1. you are a family member of a German and have had a residence permit as a family member for three years.
2. you have been living in a family partnership with a German for at least three years.
3. there is no interest in deportation (e.g. if you have committed a criminal offence).
4. you have sufficient language skills (B1 language certificate).
Furthermore, you need the following documents
1. tenancy agreement
2. proof of own earnings (employment contract and pay slips)
3. proof of active health insurance
4. valid national passport
5. a recent biometric passport photo
You must apply in person at your local foreigners authority. The fees for a settlement permit are € 113.00.
A copy of your wife's identity card is not necessary in this situation. Explain to the Foreign Registration Office that you are likely to separate. If the points described above are in agreement with you, you fulfil the requirements to get your own residence title - independent of your wife.
I wish you all the best.