Spoliation generally deals with the failure to keep evidence. I don't think the term refers to the failure to produce evidence. You don't say what type of case you have so I don't know if you are suing your employer or just trying to get documents from them to use against someone else. If your employer is a party in the lawsuit, failure to produce documents can result in court-ordered sanctions such as adverse inferences up to striking the answer. There is a line of cases that says if an employer withholds information and as a result you lose out on the chance to sue someone else because you didn't know who to sue, then you can sue the employer for causing you to lose the claim against the other party. I suggest you speak to your attorney about these issues.