1,3,2-Dioxathiolane-2,2-dioxide as film-forming agent for propylene carbonate based electrolytes for lithium-ion batteries

1,3,2-Dioxathiolane-2,2-dioxide (DTD) was investigated as co-solvent for PC based electrolytes in combination with a graphite electrode. An amount of 10wt% of DTD in PC was used to form an effective and stable SEI on graphite during the first cycle. The decomposition of DTD takes place before PC co-intercalation may happen, thus preventing the exfoliation of graphite. Additionally, the electrolyte, 1 M LiBF 4 in PC:DTD (9:1, by wt.) was proven to be compatible with NCM electrodes. Raman spectra confirmed that LiBF 4 completely dissociates into ions in PC:DTD (9:1, by wt.). The electrolyte shows better conductivities in comparison to other LiBF 4 based electrolytes and good rate capability up to 5 C on graphite. Therefore, LiBF 4 can be used as an alternative lithium salt in lithium-ion batteries, in combination with PC based electrolytes.