A battery off another machine wont fit so you can’t simply get a higher voltage one. And in any event putting a higher voltage through a motor will kill it instantly, even if you were able to.
What you can do is get a battery with a higher MAH. We typically use 3000 MAH ones.
Beware though with aftermarket cordless Dyson batteries that you buy online it will be a complete lottery as to the quality of them.