LAUSR

In this work, a novel high-voltage electrolyte additive of tetraethylthiophene-2,5-diylbismethylphosphonate (TTD) is synthesized, and the influence of TTD on the electrolyte and its electrochemical performance under different voltages are studied by changing the content of the TTD additive. The results show that the TTD additive significantly improves the capacity, cycle stability and rate capability of batteries when charging/discharging at high voltages. After adding 1% TTD to the basic electrolyte, the capacity retention rate of batteries after 200 cycles at 4.2 V, 4.3 V, 4.4 V and 4.5 V increase by 20.8%, 18.3%, 50%, and 31.9%, respectively. In addition, transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS) analysis results show that TTD can effectively inhibit the decomposition of the electrolyte and participate in the formation of a uniform, thin and stable cathode electrolyte interface (CEI) film on the electrode surface, thereby effectively inhibiting the side reaction between the electrolyte decomposition product and the CEI membrane, and finally the high voltage performance of the battery is improved. This novel TTD additive used in this work as an effective strategy to improve the high-voltage performance of the battery, which will provide a cost-effective solution for high-performance high-voltage electrolyte.