You'll need the proper wireless charging pad to take advantage of the faster charging feature.
According to MacRumors, the 11.2 update will bring support for Qi wireless charging at a rate of 7.5 watts, an improvement over the current 5-watt limit allowed by iOS 11.1.1. Updating your phone isn't enough to boost your charging speed, however.
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. 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.
Using the Belkin charger that Apple sells, which does support 7.5W charging speeds, the iPhone X was charged from 46 to 66 percent over the course of thirty minutes. A number of users of the app have reported problems with the battery on their device draining whilst using the app. Users are reporting problems with the app on both the iPhone and iPad.
MacRumors' testing suggested a slightly faster charge. Apple has not announced when 11.2 will be ready but Mac Rumors says that since it is in its third beta version, the official release should be coming soon - most likely within the next month. That requires a compatible smartphone, of course, and not all charging pads are compliant with that maximum rate.