Basically (pun intended), accelerators include a base (hydroxy- or alkyl compound) in a solvent carrier that reacts with the acid stabilizer in cyanoacrylates to accelerate the cure process. Since CA is cured via moisture (i.e, relative humidity), the higher the moisture content, the faster the cure rate. That's why skin moisture and amino acids work well to bond skin so well---which was the original purpose of CA: to bond skin edges post surgery. That's also why baking soda works well as an accelerator.
There is a trade-off, however. The faster the cure rate, the weaker the bond strength.
I've found a really good internet article on the chemistry of CA. As soon as I get a chance to cut and paste the pertinent parts, I'll post it here with the appropriate citation.
Gip Winecoff