To study the SEI formation process with different electrolyte components, five models were constructed categorized by different electrolytes and electrodes (Na metal, Hard carbon (HC)) as follows:
1. ㊀HC // ED (1.0M NaClO4 in EC : DME = 1 : 1 Vol%) // Na㊉;
2. ㊀HC // EDF (1.0M NaClO4 in EC : DME = 1 : 1 Vol% with 5.0% FEC) // Na㊉;
3. ㊀HC // EPF (1.0M NaClO4 in EC : PC = 1 : 1 Vol% with 5.0% FEC) // Na㊉;
4. ㊀Na // EDF (1.0M NaClO4 in EC : DME = 1 : 1 Vol% with 5.0% FEC) // Na㊉;
5. ㊀Na // EPF (1.0M NaClO4 in EC : PC = 1 : 1 Vol% with 5.0% FEC) // Na㊉.