Have you ever heard about Lenovo P780?i guess not.it's a 5" phone with 4000mAh battery.mind you this phone came last year.I have seen many Chinese phones having 5000mAh or even 5300mAh battery.I think you are not up on the latest technology,first you must know about technology a bit before asking such a dump question.if you think these are impossible specs then definitely you have no idea what is happening in the smarphone world,do a bit of research or update yourself then comment(btw most of these specs are already available on many phones).Any way this concept phone won't be a thinnest one so it can easily accommodate 4500mAh battery or even 5000mAh.surface pro 3 is just a tablet yet packs powerful CPU and battery that you get on massive laptops.So it is very much possible to have 4500mAh battery in 5.7" phablet.I don't honestly understand what specs you found impossible here.do you honestly think quad-core processor is impossible on phone? 4GB RAM?30MP cam?4k video?dual band wifi?hello duhhh. anyway we are not talking about a phone that will come tomorrow morning,we are talking about future.all these specs will be a mediocre ones by the time MS brings it's flagship.and by next year these specs will be on our mid range phones.I would say these specs are pretty low for THE BEST flagship phone next year.
Hah, are YOU familiar with mainstream technology? That Lenovo phone ran on a low-quality SoC (lost out in benchmarks to a year-old dual-core SoC, despite being a newer quad-core). I stated 4500 mAh doesn't happen, not 4000, and that thing's existence doesn't make it common to see something north of 3500 mAh (I can drown your one example in hundreds of devices under 3500 mAh, but that doesn't need to be done). The inclusion of that battery came at a cost to size and weight, in addition to requiring rather weak secondary specs to keep the price down, I imagine (no OIS in the camera, only 4 GB of storage, no LTE, 720p display). It was a very niche device in a constricted market.
As for what's possible/not possible, it's very dependent on when you'd think this thing could even make it to market. Look at the 1520--a 6" device whose battery was only about 75% the size of what you're asking for here. The 4 GB of RAM isn't going to happen because the highest-end ARM SoC, the SD 810, is only putting 3 GB of RAM into phones right now. The 128 GB of storage is going to run the device's price WAY up, where as you could easily go with 32 GB and microSD expansion, while shaving $100-150 off. The camera would likely result in a slight bulge in the device, going up to 30 MP, but we've seen it happen--at a $100 premium (to go from the 920 to the 1020).
Just saying "future" doesn't explain a thing. If you're talking about a device 2 years from now, maybe, but if you pay attention to where tech has been going, SoCs are being pushed to conserve battery life (big.LITTLE, Cherry Trail, Core M), so a 4500 mAh battery won't be necessary. As for next year...no, just no. Over the past 3 years, Samsung's battery in the Galaxy S line has gone from 2100 mAh (S III) to 2550 mAh (S6), yet you're calling it reasonable for Microsoft to have a battery increase of more than 30% (vs. the 1520), while shrinking the device.
Meanwhile, you're asking Microsoft to just crap out a phone running a Cherry Trail before Cherry Trail is even out. Plus, the Atom stuff's typically powering stuff a good deal larger (such as 8-inch tablets with junk optics and displays that are sold as entry-level devices). This phone would be ridiculously hot, heavy, and expensive.