1) Volumetric energy density (Ev)
As shown in Figure 1B there are tremendous effects on full cells by
substitution of graphite to Li metal anode (3 mA h
cm-2, N/P ratio = 1) on both specific gravimetric and
volumetric energy density (Eg, Ev).
Furthermore, the Eg and Ev of AFLMBs are
the maximum values that can be achieved by regulating cell
configurations. In case of Eg, only a slight improvement
in Eg (2 %) of AFLMBs over LMBs is achieved because Li
metal is only a small portion of the cell total mass compared to other
components (mainly CCs and electrolytes) due to the lightweight nature
and high specific capacity of Li.[61] However,
anode-free configurations have huge impact on Ev over
LMBs even under fully charged state. Compared to LMBs using very thin Li
metal, a 10–17 % of Ev improvement is observed
depending on cathode material. The highest Ev of AFLMBs
must be efficient when the battery needs to fit into a fixed volume,
such as in EVs.