Uniform lithiophilic layers in 3D current collectors enable ultrastable solid electrolyte interphase for high-performance lithium metal batteries

Uniform lithium plating/stripping during charging/discharging in 3D lithiophilic current collectors (3DLCC) is essential to suppress growth of lithium dendrites and to mitigate infinite volume variations of lithium metal for long-lived lithium metal batteries. This study reveals the decisive role played by uniformity of the lithiophilic layer of the 3DLCC in achieving uniform lithium plating/stripping. Herein, a series of metal oxide-based 3DLCCs are successfully fabricated with a simple and an ultrafast solution combustion method, from which formation of a uniform and stable lithium dendrite-free solid electrolyte interphase via a uniform lithiophilic layer is demonstrated. Taking Co3O4 as the lithiophilic material deposited on a nickel foam as the 3DLCC (Co@NF) for a proof of concept, the loading amount of Co3O4, closely correlated with the uniformity of the Co3O4 layer, is modulated to optimize its lithium ion hosting performances. With a uniform Co3O4 layer grown in the 3DLCC, an ultralow nucleation overpotential of 33.4 mV is achieved in half-cell tests at 1 mA cm(-2) and 1 mAh cm(-2), and a high Coulombic efficiency of 97.1% is maintained after 210 cycles under a severe cycling condition of 2 mA cm(-2) and 1 mAh cm(-2). A small polarization voltage of 13 mV together with an ultralong cycle life of 2400 h at 0.5 mA cm(-2) and 1 mAh cm(-2) in symmetric Li cells is achieved. Moreover, the composite Li anode delivers sensational rate capability and cyclability in full-cells. This work not only provides new and valuable insights into the interphasial chemistry of solid electrolyte interphase layers, but also sheds light on the development of ultra stable lithium metal batteries.

Automated summary

Uniformity of the lithiophilic layer in 3D lithiophilic current collectors (3DLCC) plays a decisive role in achieving uniform lithium plating/stripping. This study successfully fabricates metal oxide-based 3DLCCs with a uniform and stable lithiophilic layer, demonstrating the formation of a lithium dendrite-free solid electrolyte interphase. The optimized 3DLCC shows excellent electrochemical performances, including low nucleation overpotential, high Coulombic efficiency, small polarization voltage, and long cycle life.