If you have a custom kernel (I use Elementalx), you can enable "USB Fast charge" to, well, charge faster.
I'm not an expert on how this works, it probably changes the amount of current going into the battery at once (higher than stock) . That said, I'm not responsible for damage to your battery. I've been using this for months with no issues.
If custom kernel is not your thing, you can use Tasker. This requires root and the "secure settings plugin" . Looks like this :
New profile: > state > power > power > (chose which power source you want)
Now create your task :
Plugin > Secure Settings > Configuration > Custom Rom Actions > Fast Charge (set on)
This should enable fast charge when you plug in your phone.
Posted via Nexus 5 or Nexus 7 (2013)