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.