fig2

Figure 2. (A) Electronegativity values of various elements based on carbon; (B) The capacity of some reported heteroatom-doped carbon materials applied in batteries; (C) The energy density ranges of some common electrochemical energy storage devices. Reproduced with permission^[73]. Copyright 2021, The Royal Society of Chemistry; (D) Li bond formation and nucleation process on the surface of carbon substrates; (E) The binding energy between Li atom and various elements. Reproduced with permission^[75]. Copyright 2019, American Association for the Advancement of Science.