Improve High Voltage Resistance Performance of LiNi_0.8Co_0.1Mn_0.1O₂ Lithium Metal Batteries by Two Novel Aromatic Compound Electrolyte Additives

Ternary high-nickel oxide exhibits a relatively high working voltage compared with traditional lithium battery cathodes (LiFePO4, etc.). Consequently, it has been widely studied in recent years and is at the forefront of research on positive electrodes for power batteries. To achieve higher reversible capacity, it is often necessary to increase the battery operating voltage. However, there are many drawbacks to this method, such as surface cracking of the working electrode and serious side reactions with the electrolyte. The novel dual-additive combination in this work has the potential to significantly address the aforementioned issues. A composite polymer cathode–electrolyte interface (CEI) film is formed on the surface of the cathode due to two aromatic compound additives preoxidation. The stable CEI film not only improves the stability of the electrode but also suppresses solvent and hydrofluoric acid (HF) to effectively inhibit the side reaction on the cathode surface. Furthermore, these two additives can be readily reduced at the anode to form a solid electrolyte interface (SEI) membrane containing rich LiN&LiF, which effectively suppresses the formation of lithium dendrites. The battery capacity retention could be up to nearly 83% on the dual-additive electrolyte compared to the baseline electrolyte after 300 cycles. This work may provide more possibilities for future research on high-voltage lithium batteries.