Flexible Mg3N2 layer regulates lithium plating-striping for stable and high capacity lithium metal anodes

Lithium metal is regarded as one of the most promising candidates for next-generation batteries. However, lithium dendrite formation and dead lithium accumulation are the critical problems which hinder its practical application. Herein, we constructed a flexible coating membrane layer which could effectively uniform the lithium deposition by isolating lithium metal from electrolyte and regulating the ion flux distribution. After modification, both the Li‖Li symmetric cells (more than 1,400 h at 1 mA·cm−2 and 1 mAh·cm−2) and Li‖Cu cells (more than 500 cycles at 0.5 mA·cm−2 and 0.5 mAh·cm−2, coulombic efficiency over 98%) deliver excellent long-cycle performance with high coulombic efficiency. The high performance is also proved in LiFePO4 (capacity retention increases from 79% to 93% at 2 C after 400 cycles) and NCM811 full cells (capacity retention from 28.5% to 78% at 2 C after 500 cycles). High electro-performance in batteries demonstrates that the multifunctional layer plays a crucial role in stabilizing lithium anode. Moreover, in order to verify the universality of the method, we have extended this facile way to fabricate other types of flexible membranes. This work offers an insight into solving the current obstacles in the application of lithium metal batteries.