Enhancing the performance of Ni-rich lithium metal batteries through the utilization of amine-functionalized 1D/3D nano shields and additives in high-voltage operation

Abstract

The development of high-energy–density lithium metal batteries (LMB) is of paramount importance for various emerging energy storage applications, and high-voltage operating system based on high-capacity nickel-rich layer LiNixCoyMn1xyO2 (Ni-rich NCM, x ≥0.6) cathode combined with a Li metal anode is a representative promising solution. However, it is challenging to stabilize the lithium metal anodes with severe operating conditions, mainly because dissolved transition metal (TM) ions from the cathode trigger harmful side reactions, such as electrolytic decomposition and the growth of dendritic Li structures, resulting in serious safety hazards. In this study, we fabricated an ion-entrapping functional separator using amine-functionalized 1D or 3D inorganic particles confirmed by DFT calculation. Then, we applied in the Ni-rich LMB, demonstrating suppression of TM ion cross-over of 47% compared to conventional PE separators leading to improved cycle numbers and capacity retention at high-voltage operation. Further, combining functional additive introduction with the transition metal cross-over shielding separator resulted in synergistic ion capturing up to 84%. The results of this study provide new insights into the design of advanced LMB for high-energy–density.