Efficient Lithium Growth Control from Ordered Nitrogen-Chelated Lithium-Ion for High Performance Lithium Metal Batteries.

Lithium (Li) metal has attracted significant attention as next-generation anode material owing to its high theoretical specific capacity and low potential. For enabling the practical application of Li-metal as an anode according to energy demands, suppressing dendrite growth by controlling the Li-ion (Li) is crucial. In this study, metal-organic frameworks comprising bipyridinic nitrogen linker (M-bpyN) are proposed as 3-dimensional (3D) Li guiding matrix. The proposed approach creates ordered electronegative functional sites that enable the preoccupied Li in the ordered bipyridine sites to produce isotropic Li growth. The Li guiding matrix containing 3D ordered bipyridinic N sites introduces preoccupied Li sites that attract the Li growth direction, thereby suppressing the dendrite growth during the electrodeposition of Li. After applying the M-bpyN layers, stable lifespan of up to 900 cycles in the Li|M-bpyN|Cu cell and over 1500 h of operation in the Li|M-bpyN|Li symmetric cell is achieved. Moreover, the Li|M-bpyN|LiFePO configuration shows a long cycle retention of 350 cycles at 0.5 C. These results indicate that an M-bpyN Li guiding matrix, which enables a uniform Li flux by 3D ordered Li-chelating sites, serve as a suitable host for Li and enhance the performance of Li-metal electrodes.