Lithium Ion is the current technology powering our Smart Phones.....for now.
But ask Samsung if they are going to go looking for an alternative?
Lithium Ion has the best power for size ratio out there, but it has inherent dangers, the chemicals in them will thermo-genically react and melt your phone. Hence the Note 7 issue.
The Note 7 is not alone, they just had a higher failure rate. Google “Any Smartphone” and “Fire”.
The media went after Samsung almost as hard as they go after Trump. Samsung pulled the plug on the Note 7, the media once on a narrative cant control themselves, I can see them going after Apple next.
And this thermo failure also has effected the Hybrid and Electric car industry.
I have been buying Lithium Ion rechargeable cells for various projects for several years not to mention cell phone and computer batteries that have gone bad. As you say they have “the best power for size ratio” but they are a pain in the rump in so many ways. I have had them overheat and be destroyed. I have had them be destroyed by over-charging and conversely they have been destroyed just by letting them sit on the shelf too long and get undercharged. They can be destroyed if something bad happens to the built in circuitry that is suppose to protect them. I have many NiCad and lead acid based gel cells that are 20 years old and still functioning at a fairly high percentage of their initial capacity. But I have dozens of lithium ion cells that barely were used and have gone bad... a whole lot of of wasted dollars.
It was inevitable that when applications such as hybrid and electric cars became more popular which use much larger batteries... that is would put a strain on the supply of lithium and the price would “necessarily sky rocket”. Why is it that the people and entities advocating for “alternative energy” solutions never seem to plan for the most basic concept of supply and demand? It is because at this time the entire “eco” game is all smoke and mirrors. Governments are using it to funnel billions of dollars into the pockets of their cronies while the real backbone of the energy based economy is going to be “carbon based” fuels for the foreseeable future.