Interesting link, Gvander, but...
we don't have enough comparisons to their data. From the Hanil-Valence specs (our current best guess as to the Valence Mn-O2 cathode performance), Valence has 147 wh/kg at 3.8 volts (or , if you prefer, the spec sheet for the various cellphone/pda batteries show 142 wh/kg). This gives 38.6 amp-hours/kg, or 38.6 mAh/g (again, at 3.8 volts). Putting this data point on their chart comparing their battery's specific capacity to other types, the Valence data point is well above what they plot for Li-Mn-O2, and at the outer kink in the Li-ion curve.
But we don't know what the tradeoffs are for the Valence cells if they are configured for and operated at lower voltages. Given the discrepancy between the 'OnPower' curve for the Manganese cells, and what Valence has attained, the 'OnPower' curve cannot be the basis for a comparison between their battery and ours.
Further, they also indicate their cell voltages are lower (2 volts, down to 1 volt for higher capacity). Is this a necessity, to attain such energy densities/capacities? Can anyone here comment on the theoretical capacity, cell voltage, etc. for lithium metal vs. various lithium-ion and lithium-ion-polymer formulations? (not my field...)
More significantly, the issue of the number of recharge cycles is not really addressed. Sure, they show a flat curve out to 50 cycles, but why don't they show beyond that? We know officially that Valence has over 500 recharge cycles, and unofficially more than twice that.
They (OnPower) note that they use a 'proprietary process' to dissolve lithium dendrites, and rely on 'super high homogeneity cathode material for dendrite-free batteries.' So my guess is that this is a lithium metal battery, which would explain any performance enhancement. But how well they can translate these laboratory processes to large-scale manufacturing, and retain the control needed to attain the long-sought-after lithium metal battery, remains to be seen. Many have tried and failed...
Remember what happened to Valence, before they went back to the lab and then resorted to the Bellcore approach, using li-ion? We'll be watching these guys, you can be sure.
Lev mentioned an Italian outfit during the SM, who were a potential competitor down the road, and it looks like this is them. Meanwhile, they're probably at least a year away from production, assuming everything goes right and Zeev's 'Mr. Murphy' doesn't show up to say, 'Gotcha!'
Thanks for the link, GV. |
