Anticorrosive Copper Current Collector Passivated by Self-Assembled Porous Membrane for Highly Stable Lithium Metal Batteries

The regulation of lithium plating/stripping behavior is considered to be critical for next-generation safe and high-energy-density lithium metal batteries. Lithium deposition with maximum granular size and minimum microstructural tortuosity can significantly improve the lithium plating/stripping efficiency. Here, a self-assembled organosilane layer with nanopores is constructed on Cu current collector surface via a thiol-Cu reaction. In contrast to typical stacked-particle morphology with small grain size and high specific area in ether electrolyte, dough-like and lateral-growth lithium deposition can be plated on the modified Cu current collector due to the low surface energy of a lithiophilic Si-O-Si membrane. The planar and dense lithium deposition contributes to the stable implementation of up to near 500 cycles in full cells with high-loading LiFePO4 cathode. Anticorrosion in rigorous Cl-ion containing solution can even be achieved due to the corrosive repellency of hydrophobic organosilane. A high Coulombic efficiency (97.12%) is remained after corroding for 300 min. Moreover, the irreversible capacity loss caused by galvanic corrosion, an ignored but crucial aspect, has been significantly suppressed due to the passivation of high-redox-potential Cu by organosilane coating.

Automated summary

The formation of a self-assembled organosilane layer with nanopores on the Cu current collector surface allows for a unique lithium deposition mechanism, resulting in planar and dense lithium deposition with improved stability and cyclability in high-loading LiFePO4 cathodes. The organosilane coating not only enhances the lithium plating/stripping efficiency, but also provides resistance to galvanic corrosion and corrosive repellency in Cl-ion containing solutions.