ZnO-decorated nanoperforated graphene hosts with synergistic dual lithiophilic sites for dendrite-free lithium anodes

초록

Lithium (Li) metal is a promising next-generation anode material owing to its high energy density. However, the growth of Li dendrites and volume changes during charge-discharge hinder the commercialization of Li metal anodes. To address these issues, we propose the use of lithiophilic nanoperforated graphene (NPG)/ZnO composites as a Li-host material. The synergistic dual-lithiophilic sites, composed of lithiophilic ZnO and oxygencontaining functional groups at the edge sites of NPG, effectively lower the Li-plating overpotential and facilitate Li-ion migration into the host. Consequently, uniform and dendrite-free Li deposition occurs within the host rather than on its surface. Density functional theory (DFT) calculations further confirmed that these dual sites synergistically enhance Li adsorption and reduce the nucleation barrier, elucidating the underlying mechanism of uniform Li deposition. Accordingly, NPG/ZnO symmetric-cells exhibit stable voltage profiles for over 120 h at 5 mA cm- 2 without short circuit. Further, we achieved a low Li plating/stripping overpotential of approximately 101.5 mV at 10 mA cm- 2. Moreover, at an extremely high areal current density of 5C (7.56 mA/cm- 2), NPG/ ZnO-Li full-cells paired with LiFePO4 (LFP) cathodes show excellent cycling stability over 200 cycles. The results of this study provide a facile pathway to cost-effective Li-host materials for application in dendrite-free Limetal anodes.

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