Theoretical Study on Graphite and Lithium Metal as Anode Materials for Next-Generation Rechargeable Batteries

Dr. Gabin Yoon received a B.Sc. degree (2013) and Ph.D. degree (2019) in materials science and engineering from Seoul National University. His research interest lies in the theoretical study of electrode materials for Li and Na rechargeable batteries using density functional theory and continuum mechanics.  ​

lt;p>1           Introduction      1

1.1        Demands for energy storage system     1

1.2        Li-ion batteries 1

1.3        Post Li-ion batteries      3

1.3.1     Na-ion batteries             3

1.3.2     Li metal batteries           5

1.4        References       6

2           Na intercalation chemistry in graphite   9

2.1        Introduction      9

2.2        Experimental and computational details            10

2.2.1     Materials           10

2.2.2     Electrode preparation and electrochemical measurements        10

2.2.3     Operando XRD analysis             11

2.2.4     Computational details   11

2.3        Staging behavior upon Na-solvent co-intercalation        12

2.4        Na-solvent co-intercalation into graphite structure        15

2.5        Solvent dependency on electrochemical properties       20

2.6        Conclusions     24

2.7        References       27

3           Conditions for reversible Na intercalation in graphite    31

3.1        Introduction      31

3.2        Computational details   32

3.3        Unstable Na intercalation in graphite    33

3.3.1     Destabilization energy of metal reconstruction 35

3.3.2     Destabilization energy of graphite framework upon intercalation           37

3.3.3     Local interaction between alkali metal ions and the graphite framework             37

3.3.4     Mitigating the unfavorable local interaction between Na and graphene layers             39

3.4        Conditions of solvents for reversible Na intercalation into graphite       41

3.4.1     Solvent dependency on reversible Na-solvent co-intercalation behavior             41

3.4.2     Thermodynamic stability of Na-solvent complex            43

3.4.3     Chemical stability of Na-solvent complex          46

3.4.4     Unified picture of Na-solvent co-intercalation behavior 47

3.5        Conclusions     48

3.6        References       48

4           Electrochemical deposition and stripping behavior of Li metal  53

4.1        Introduction      53

4.2        Computational details   55

4.3        Effect of deposition rate            57

4.4        Effect of surface geometry        60

4.5        Implications of SEI layer properties       63

4.6        Consequences of the history of deposition and stripping          70

4.7        Conclusions     72

4.8        References       72