Enhanced cyclic stability of Ni-rich lithium ion battery with electrolyte film-forming additive

Improving the interphasial stability of electrode/electrolyte is crucial to the large-scale applications of lithium-ion battery with high energy density. Herein, a novel electrolyte additive, phenyl trans-styryl sulfone (PTSS), is proposed to reconstruct the interphasial structure and composition of electrode/electrolyte and to improve the cyclic stability of high voltage LiNi0.8Co0.1Mn0.1O2 (NCM811)/graphite full-cell. Specifically, the cell with PTSS additive maintains 63% of its initial capacity after 100 cycles at 1C, which is about 15% higher than that of baseline electrolyte. Theoretical calculation and experimental characterization reveal that the high electrochemical reactivity PTSS decomposes prior to the baseline electrolyte, generating a protective film on NCM811 cathode and graphite anode surface. The uniform and thin CEI film effectively enhanced the interphasial stability of NCM811 cathode via suppressing electrolyte oxidation and electrode interphasial destruction during long term cycling. In addition, the PTSS induced-SEI film enhances the interphasial stability of graphite anode. (C) 2019 Elsevier B.V. All rights reserved.