Battery Energy Density
The outstanding feature of lithium battery is the high energy density, that is, the high energy of per unit of weight or volume. The gravimetric energy is shown by wh/kg and volumetric energy density by wh/l. wh -the unit of energy, w refers to voltage, and h refers to hour; kg is kilograms (the unit of weight) and L
is liter (the unit of volume). For instance, the rating voltage of 5# nickel cadmium cell is 1.2 V, the capacity is 800mAh, while the energy is 0.96Wh(1.2V×0.8Ah). In contrast, as for the 5# Li-MnO2 battery of the same size, the rating voltage is 3v, the capacity 1200mAh and energy 3.6Wh. Although the two batteries have the same volume, the
energy of the latter is 3.75 times that of the former.