Assertion: hydrogen's energy density | /r/HasProperty | one third
Facets:
value: as that of a lithium battery
type: OTHER
Source sentences:
text: While the energy density is only around one third as that of a lithium battery, the distinctive virtue of the nickel–hydrogen battery is its long life: the cells handle more than 20,000 charge cycles with 85% energy efficiency and 100% faradaic efficiency.