Tri(2-furyl)phosphine-induced robust interphases for durable Nickel-rich Lithium-ion batteries

Ni-rich LiNi x Co y Mn 1−x−y O 2 /graphite batteries with Ni ≥ 0.8 have aroused great interest in high-energy–density Li-ion batteries. However, their practical applications still face huge challenges owing to severe capacity fading on unstable cathodic solid electrolyte interfaces (SEI). Herein, we propose an advanced electrolyte additive , tri(2-furyl)phosphine (FuP), to induce the simultaneous formation of robust SEI films on cathode and anode surfaces. This interphase can significantly improve the cyclability of commercial LiNi 0.8 Co 0.1 Mn 0.1 O 2 /graphite pouch cells at 45 °C and reduce cell impedance during cycling. The capacity retention rate of the cells with the FuP-based electrolyte can reach 90 % after 600 cycles, which is considerably better than that of baseline batteries (70 %). Mechanistic studies indicate that FuP suppresses the formation of fragile Li 2 CO 3 to generate more stable LiF, Li x PO y F z , and additional organic phosphorus species on the electrode surface, thereby preventing cation disorder and irreversible phase transitions. These results provide a facile and efficient strategy for enhancing the performance of Ni-rich Li-ion batteries.