Apple has added support for 7.5 watt wireless charging for iPhone X, iPhone 8, and iPhone 8 Plus in the iOS 11.2 beta.
Apple has yet to release its AirPower charging pad; however, there are some third party options that work well with the iPhone. You'll need the proper wireless charging pad to take advantage of the faster charging feature.
Qi chargers can support 15W of wireless charging, but it's not known whether Apple's iPhone lineup can do the same. Our favorite wireless charger for the iPhone X, 8, and 8 Plus indeed supports 7.5W charging. Using a non-7.5W wireless charger topped the same iPhone X from 46% to 60% in over 30 minutes, which speaks of marginal gains here and there, but gains nonetheless.
The smartphones, which can charge wirelessly with Qi-based accessories like the Belkin and Mophie pads, will be able to charge at 7.5 watts with iOS 11.2. Still, if you're a supporter of wireless charging, faster charging speeds can only encourage you to embrace the cable-free future (and will probably get you to stop fiddling with your phone). The iOS 11.2 beta is now available for developers only, but could launch soon to the public.