I have access to the paper. First, the actual measured capacity is 685 Wh/kg, not 1200; the researchers stated they hope to reach the latter figure with further development. In order:
- Wh/L is 619, so the battery just barely floats. The absence of a dense metal oxide cathode probably makes it lighter than the usual lithium battery cell (which have s.g. ~2).
- Charging rate is given as 1 A/g for a 1 Ah/g electrode, so these numbers were measured with a 1-hour charge time. Data for higher charge rates is buried in the Supporting Information (which may be public?)
- Discharge rate is the same.
- Cost to produce is unclear. The electrolyte contains about 1-2% germanium (5 wt% of Li10GeP2S2), and the cathode contains molybdenum. It is difficult to give the Mo concentration with certainty because the specific area of the cathode is given as "250 g/m^2" but it should be as "m^2/g". Assuming a simple typo, the cathode contains 25 mg of Mo per cubic centimeter, which is sometimes written "2.5% w/v". These are rare elements, but the concentrations are rather low. The use of toxic sulfides (H2S risk) may increase production costs.
Coulombic efficiency, which you didn't ask for, starts at 93% and drops to 88% after 1000 cycles, so pretty good but a little lower than you expect from a typical lithium battery.
Wh/kg is an insufficient metric for air batteries. One needs Wh/kg at full charge and separately or full discharge, or kg/Wh charged and additional kg/Wh per unit Wh discharged, or something along those lines.
(kg/Ah discharged could be used to estimate electrons per oxygen atom absorbed, too.)
- Wh/L is 619, so the battery just barely floats. The absence of a dense metal oxide cathode probably makes it lighter than the usual lithium battery cell (which have s.g. ~2).
- Charging rate is given as 1 A/g for a 1 Ah/g electrode, so these numbers were measured with a 1-hour charge time. Data for higher charge rates is buried in the Supporting Information (which may be public?)
- Discharge rate is the same.
- Cost to produce is unclear. The electrolyte contains about 1-2% germanium (5 wt% of Li10GeP2S2), and the cathode contains molybdenum. It is difficult to give the Mo concentration with certainty because the specific area of the cathode is given as "250 g/m^2" but it should be as "m^2/g". Assuming a simple typo, the cathode contains 25 mg of Mo per cubic centimeter, which is sometimes written "2.5% w/v". These are rare elements, but the concentrations are rather low. The use of toxic sulfides (H2S risk) may increase production costs.
Coulombic efficiency, which you didn't ask for, starts at 93% and drops to 88% after 1000 cycles, so pretty good but a little lower than you expect from a typical lithium battery.