At rated capacity, this is 280Wh/kg, and at minimum capacity, it is 270Wh/kg.
I’ve seen semi-custom form factors reach 300Wh/kg without taking into account lower packaging efficiency(which is functionally the highest with cylindrical cells), so this is impressive.
I wonder what is different about it at the chemistry level.
Some photos of M58T samples from Nkon. It can be seen that cells were removed from modules, but the welds are nicely cleaned. An interesting feature is the use of a one-side busbar connection in that app, I guess laser was used for welding. The dark circle in the middle of the positive terminal is probably caused by the laser as some surface treatment.
Can you check the actual dimensions and post them here? Diameter, length, etc. Because according to the information from NKON and EVVA, it looks like this cell is a bit larger than the usual standard and I’m wondering if it will fit in some of my light where it was a tight fit.
The one possibility for why safety is an issue is that LG likely found a way to increase the thickness of the electrodes through an innovation internally, but without finding a way to offset the internal resistance loss of such a change.
That would mean the cell gets hotter, losing more cycles, and all of the usual stuff during charging, and they don’t want warranty claims because of that.
It looks like a very thin positive terminal that’s already bent/ pushed down near the lower left leg in the picture. Flat tops of many cells are not really designed to be abused and or dropped in flashlights even with springs in both ends.
Unfortunately, due to the declared larger dimensions D: 21.7 mm and H: 71 mm, the volumetric energy density is only 768 Wh/l and therefore the “magic” value of 800 Wh/l in cylindrical format still resists.
I can do measurement and weighing on Monday at first. The EVVA dimensions are max. limit values delcared by LG. It seems that Nkon samples used a thicker tube than LG original tube.
with tube: D: 21.6 mm, H: 71.2 mm, Weight: 71.8 g (Nkon transparent tube)
without tube: D: 21.4 mm, H: 70.5 mm, Weight: 70.8 g (this cell have an elevated positive terminal)
So without tube and with 20.3 Wh as measured nominal 0.2C energy it makes exactly 800 Wh/l
I measured 5700mah from the cell included with my Sofirn LT1 Mini using a SKYRC MC3000. I wonder if they used this cell and rewrapped it. The positive contact looks to be the same shape. BLF LT1 Mini Review – At Long Last – Grizzly's Reviews