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

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium (Li) metal is a promising next-generation anode material due to its high specific capacity and low potential.
• Controlling lithium-ion (Li+) behavior is critical to suppress dendrite growth and enable practical Li-metal anode applications.

Purpose of the Study:

• To develop a 3D Li guiding matrix using metal-organic frameworks with bipyridinic nitrogen linkers (M-bpyN).
• To investigate the ability of M-bpyN to control Li+ flux and promote isotropic Li growth, thereby suppressing dendrite formation.

Main Methods:

• Fabrication of M-bpyN layers as a 3D Li guiding matrix.
• Electrochemical testing of Li|M-bpyN|Cu cells, Li|M-bpyN|Li symmetric cells, and Li|M-bpyN|LiFePO4 configurations.

Main Results:

• M-bpyN layers create ordered, electronegative sites that guide Li+ deposition, leading to uniform Li growth.
• Achieved stable lifespans of up to 900 cycles in Li|M-bpyN|Cu cells and over 1500 hours in Li|M-bpyN|Li symmetric cells.
• Demonstrated long cycle retention of 350 cycles at 0.5 C in Li|M-bpyN|LiFePO4 cells.

Conclusions:

• The M-bpyN Li guiding matrix effectively suppresses dendrite growth by enabling uniform Li+ flux through 3D ordered Li+-chelating sites.
• M-bpyN serves as a suitable host for Li+, significantly enhancing the performance and stability of Li-metal electrodes.