fig1

Figure 1. (a) Comparison of energy density for various battery prototypes. Average values are calculated using the available data, where (A) represents cathode, (B) represents both electrodes and (C) represents full cells (LIB normalized). (b) Volumetric and gravimetric energy densities of commercial batteries (LIBs, KIBs, SIBs, Ni-MH, Ni-Cd and lead-acid). Reproduced with permission from Ref.^[21] (Copyright 2020, Journal of Alloys and Compounds, Elsevier). LIBs: Lithium-ion batteries; KIBs: potassium ion batteries; SIBs: sodium ion batteries.