Phosphorus‐Containing C 12 H 27 O 4 P as Functional Electrolyte Additives for High‐Voltage LiNi 0.5 Mn 1.5 O 4 /Graphite Li‐Ion Batteries with Excellent Electrochemical Performance

As the most promising cathode material in new energy resources, LiNi 0.5 Mn 1.5 O 4 (LNMO) are widely researched due to its high platform, low cost, and environment‐friendliness, when they are assembled with graphite into battery which can lead to a faster capacity decay because of unstable solid–liquid interface. This work is devoted to stabilize electrolyte and protect interface of LNMO/graphite full battery by adding multifunctional additive, tributyl phosphate (TBP). Theory calculation which exhibits disconnection of TBP can participate in the reaction to form a uniform and dense cathode electrolyte interface film (8–10 nm) and solid electrolyte interface film around 15 nm on both electrodes, more importantly, the existence of phosphoric acid functional group can hinder the attack of hydrofluoric acid and protect electrode film. Besides, comparing with its homolog, the high‐voltage LiNi 0.5 Mn 1.5 O 4 /graphite battery with 1% TBP shows a preponderant discharged capacity retention of 77.8% after 150 cycles, while the blank is only 66%, this work provides a direction for electrolyte additives’ selection at high voltage and has far‐reaching significance for the application of phosphate ester materials.