Whether or not your battery can be used for this depends on two things:
1) How easy your battery pack is to open up
2) How ambitious you are in opening up your battery pack
I have seen three basic types of battery cases
The easiest are assembled with standard screws...nothing special there!
To make things more difficult my battery pack used special security torx bits. A cheap security bit set at Ace Hardware contained the bits I needed. Here is the $3 bit set available online for $3.
The hardest type would be a battery case that is not screwed but glued together (for example, my laptop battery...which I'm debating doing this to)...some of these were never designed to be disassembled and you may break it in the process! I suggest that you do not attempt to open one of these up unless you could see a way to get it apart cleanly, were desperate to upgrade, or about to throw it in the trash...basically you need to be willing to risk destroying the case. You may be able to re-assemble without any signs that you've taken it apart, or you may damage the case beyond repair...you'll have to be the judge.