(625f) Enhancing the Stability of High-Voltage Lithium-Ion Battery By Sulfur-Containing Electrolyte Additives

In this work, the influence of two sulfur-containing electrolyte additives, prop-1-ene-1, 3-sultone (PES) and 1, 4-bultane sultone (BS) on the cyclic stability of LiNi_1/3Co_1/3Mn_1/3O₂ (NMC111) cathode and graphite anode have been simultaneously evaluated. The capacity retention was significantly increased from 69% to 86.9% after 80 charge−discharge cycles due to the addition of 3 vol.% BS in the electrolyte, and significantly increased from 69% to 85.1% after 80 charge−discharge cycles due to the addition of 2 wt. % PES in the electrolyte. The mechanism of BS and PES improving the cyclic stability of NMC111 was investigated via theoretical calculation and experimental characterizations. The data indicates that the improved cycling stability could be ascribed to the participation of PES and BS in the formation of a thin and uniform film on the NMC111 cathode. This film effectively suppresses the subsequent decomposition of baseline electrolyte and further structure degradation of NMC111, resulting in improved cyclic stability of NMC111/Li on high work voltage. Meanwhile, according to the charge− discharge test on the graphite/Li, BS and PES-containing cells show stable cycle efficiency on graphite anode during 50 cycles.