Dual-regulation of ions/electrons in a 3D Cu-CuxO host to guide uniform lithium growth for high-performance lithium metal anodes

摘要

Three-dimensional (3D) current collectors have shown great potential in realizing practical Li metal anodes for next-generation high-energy battery systems. However, 3D current collectors suffer from a common phenomenon of preferential Li accumulation on the top surface due to lack of regulation to Li-ion transport. This study achieves dual-regulation of ions/electrons in a 3D Cu-CuxO host by porous CuxO nanowires vertically aligned on the skeleton of commercially available Cu foam, whereby Li is guided to nucleate and grow uniformly throughout the electrode rather than deposit on the top surface. The porous CuxO nanowires not only contribute to uniform distribution of Li-ion flux, but also lead to a uniform electron transport pathway. Moreover, the lithiophilic Cu-CuxO host can induce uniform Li deposition along the nanowires without growth of Li dendrites. As a result, the Cu-CuxO current collector displays ultrahigh coulombic efficiency (99.5% over 350 cycles), a long lifespan (>1800 h), and excellent rate performance, which makes it a promising anode for rechargeable Li-based batteries.