Holey wrinkled-multilayered graphene scaffolds for uniform Li-ion flux enabling high-performance lithium metal anodes

초록

The practical use of lithium metal anodes (LMAs) is impeded by uncontrolled dendrite growth, primarily caused by uneven Li-ion flux and significant volume changes during cycling. To overcome these challenges, we present binder-free holey wrinkled-multilayered graphene (HWMG) scaffolds for high-performance LMAs with long cycle life. Holey graphene oxide (HGO) sheets were restacked into particle-like holey wrinkled-multilayered graphene oxide (HWMGO) in a high-concentration GO suspension, in which few-layer HGOs were quickly stabilized and wrinkled during the drying process, and upon reduction, they transformed into HWMG. HWMG exhibited excellent adhesion due to chemical interactions via edge-located functional groups. Its particle-like morphology, with numerous nanopores and high porosity, conferred outstanding mechanical flexibility and low tortuosity, enabling uniform Li-ion flux, buffering volume expansion, and suppressing dendrite growth. As a result, excellent long-term stability over 800 cycles and a voltage hysteresis of ca. 7 mV over 6000 h were realized for the HWMG scaffolds, and a high areal capacity of 3.34 mAh cm−2 at 0.3 C after 350 cycles was demonstrated in a full-cell configuration. This work promotes the practical application of LMAs by offering a scalable scaffold design that suppresses dendrites and enhances cycle life.

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