Suppressing Universal Cathode Crossover in High-Energy Lithium Metal Batteries via a Versatile Interlayer Design

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium metal batteries (LMBs) face capacity degradation and safety concerns due to cathode crossover.
• High-energy cathodes exacerbate these issues, limiting LMB performance.

Purpose of the Study:

• To develop a multifunctional interlayer for LMBs.
• To simultaneously regulate lithium deposition and suppress cathode crossover.
• To improve the cycling stability and safety of high-energy LMBs.

Main Methods:

• Fabrication of a thin (≈25 μm) interlayer with multifunctional active sites.
• Characterization using X-ray photoelectron spectroscopy and synchrotron X-ray experiments.
• Assembly and testing of lithium metal cells with various high-energy cathodes (e.g., LiNi_0.7 Mn_0.2 Co_0.1 O₂, Li_1.2 Co_0.1 Mn_0.55 Ni_0.15 O₂, sulfur).

Main Results:

• The interlayer induced a dual-gradient solid-electrolyte interphase and provided lithiophilic sites, enabling stable Li stripping/plating at 10 mA cm^-2.
• N-rich framework and CoZn dual active sites effectively mitigated cathode crossover and Li corrosion.
• Assembled cells demonstrated significantly improved cycling stability, even with high cathode loading.

Conclusions:

• The developed interlayer is a versatile solution for enhancing the performance of high-energy LMBs.
• Simultaneous regulation of Li deposition and suppression of cathode crossover are crucial for stable LMB operation.
• This approach offers a promising strategy for advancing next-generation lithium metal battery technology.