Novel additives-package to mitigate the failure modes of high-capacity LiNi0.82Co0.11Mn0.07O2-based lithium-ion battery

Electrolyte additive strongly influences on energy density and cycle-life of state-of-the-art lithium-ion batteries (LIBs). Without additive, inevitable side reactions at nickel-rich cathode-electrolyte and anode-electrolyte interfaces result in non-satisfactory solid electrolyte interphase (SEI) formation and performance failure due to metal-dissolution from cathode particularly under multiply harsh condition of high voltages and temperatures. Herein, we report the design of a novel additives-package comprising of lithium borate, fluorinated anhydride and fluorinated phosphate at <= 1 wt% for a LIB with markedly improved capacity and performance. We show the synergy effects of individual additive in forming robust SEI layers at both 82% nickel (NCM-82) cathode and graphite anode under 4.35 V, 45 degrees C and 1C rate by compensating one's lacking role(s) by others'. Failure modes of NCM-82 chemistry LIBs such as high-voltage instability, metal-dissolution and cracks, surface and structural instability are mitigated, enabling high-capacity of 210 mAh g(-1) and high capacity retention of 94% after 100 cycles, with respect to reference electrolyte. Moreover, long cycle-life of 300 cycles of single-layer Li-ion pouch cell at 2C and 100 cycles of industrial pouch LIB (45 mAh cm(-2)) at 1C is achieved. Our design strategy for additives-package offers a promising path to long-cycled high-energy LIBs.

Automated summary

This article investigates the influence of electrolyte additives on the performance of lithium-ion batteries, and proposes a novel additives-package design to enhance the capacity and performance. The results demonstrate the synergistic effects of individual additives in forming stable solid electrolyte interphase layers on both the cathode and anode, leading to improved battery capacity and retention. The proposed additives-package offers a promising approach for long-cycle high-energy lithium-ion batteries.