A Norwegian tech company says its "SiliconX" battery can let you drive over 600 miles or power your smartphone for a week on just a single charge when compared to an equivalent volume of Li-ion cells. Its secret is a proprietary mixture of silicon and graphite that will give up to a five-fold in battery capacity over current Li-ion technology.
https://www.notebookcheck.net/New-silicon-graphite-mixture-promises-over-four-times-the-battery-life-of-traditional-Li-ion-batteries.317688.0.html
All of these "breakthroughs" are pointless to be spread out as news because we KNOW there are means of getting better battery capacity.
The biggest problem is finding a safe, scalable, manufacturable chemistry. That is the biggest issue.
And here we go again... Another one.