Huawei has recently shown a new battery technology using a 3Ah graphite-coated anode in a lithium-ion prototype that can charge to almost 50% in 5 minutes (a smaller 600mAh battery can get to 68% in 2 minutes.) Here's a video of the Huawei demo: http://v.qq.com/page/f/0/u/f0172ovjg0u.html
The Huawei battery requires a special charger similar to the one Qualcomm recently announced. (The Qualcomm charger can charge a dead smartphone battery to 80% in 35 minutes.)
This advance coupled with continued reduction in the power necessary to run new smartphones could result in smaller batteries and yet thinner phones. No word as to when we might expect to see a product using this technology.
Here's the Huawei press release on the technology: http://www.huawei.com/en/news/2015/11/Huawei%20reveals%20the%20next%20generation%20of%20quick%20charging%20technology