Stabilized Cathode Interphase for Enhancing Electrochemical Performance of LiNi_0.5Mn_1.5O₄-Based Lithium-Ion Battery via cis-1,2,3,6-Tetrahydrophthalic Anhydride

The continuous degradation of carbonate electrolytes and the dissolution of transition metal cations due to parasitic reactions on the cathode-electrolyte interphase (CEI) block the practical application of LiNi0.5Mn1.5O4-based lithium-ion batteries (LNMO-based LIBs) at a high voltage. cis-1,2,3,6-Tetrahydrophthalic anhydride (CTA) has been used as a functional additive in a carbonate baseline electrolyte (BE) for constructing the CEI film to enhance the cyclic stability of LNMO-based LIBs. The LNMO/Li cell with CTA exhibits a preponderant capacity retention of 83.3% compared with those of propionic anhydride (PA) (46.5%) and BE (13.6%) after 500 cycles at the current density of 1 C from 3.5 to 4.9 V. Additionally, the LNMO/graphite full cell with CTA still has a higher capacity retention of 95.46% even after 300 cycles at 1 C. By characterizations, it is reasonably demonstrated that CTA was oxidated to participate in the construction of a CEI film. An unsaturated aromatic group was introduced into the composition of the CEI film along with CTA in the formation process of the CEI film, which further improved the antioxidative activity of the CEI film under the influence of field-effect. Specifically, the CEI film obtains appreciable stability because of its higher antioxidative activity under the influence of field-effect. The stabilized CEI can significantly suppress the parasitic reactions of electrolytes, decrease the consumption of active-Li+, and protect the LNMO cathode structure, thereby enhancing the cyclic compatibility of LNMO-based LIBs with the carbonate electrolytes from 3.5 to 4.9 V.