They claim: 1400 Wh/l and 405 Wh/kg using etched silicon wafers:
each 12-inch silicon wafer consists of some 36 million of these vertical “micro-batteries” machined into the wafer’s surface. Which, as the explainer video argues, decreases the charge time of the macro-battery (made up of many micro-batteries) as well as the manufacturing cost of the technology, as it’s based on already scaled-up silicon fabrication processes used in computer chip manufacturing today
Apparently this makes it easy to recycle. No dendrites.
XNRGI has “has already built more than 600 working samples (8 billion micro-batteries) for a wide range of clients.
Very interesting idea. At 0.5 Kwh/kg (and 1.8 Kwh/lt !) they start to become a real interesting solution for applications like electric planes and robotics.
For general application where weight is not a big concern (like cars and back up power solutions/load levelling) I believe that all what will matter will be the cost/Kwh. They mentioned a production cost of 150 $/Kwh, Tesla should be already around 100 $/KWh right now, and they will probably have an additional interesting drop in price once Maxwell technology is fully implemented in their production lines.
For renewable storage, the main concern will be how well it will accept charging with variable loads that are very common in renewable sources. In that field I think that organic liquid batteries might still hold an advantage.
If the internet is correct, a wafer weighs 128g. So this is roughly 50 Wh/wafer, 0.0685 Wh/cm^2. A solar cell at 20% efficiency is max 0.0272 W/cm^2.
So a layer of this battery behind a solar cell would store circa 2.5 hours peak power from the cell.
My 2.5kw roof cells modified (replaced!) like this could store 6.25 kWh, enough to get me through most evenings....and during the day (in Scotland) I usually generate surplus power of that scale, except in bad weather/season.
Really quite interesting! I'll look again and try to cross-check the areal energy density.
I've heard there are liars, damned liars and there are battery engineers. But this is beyond even the prophecies of the old testament
Making a bulk quantity commodity like large scale storage li-ion batteries from semiconductor grade single chrystal silicon ingots. And claiming it to be cheaper than existing solutions....