Energy Density

Energy density indicates how much energy a battery can store relative to its weight (gravimetric, in Wh/kg) or its volume (volumetric, in Wh/l). For mobile applications like electric vehicles, gravimetric energy density matters most, while volumetric density matters more for space-constrained or stationary applications. Through active research, sodium-ion cells have now nearly caught up with lithium iron phosphate cells in gravimetric energy density, though the gap in volumetric density remains more pronounced for now.