Hierarchical Oα-rich Co3O4 nanoarray anchored on Ni foam with superior lithiophilicity enabling ultrastable lithium metal batteries

Lithium metal batteries (LMBs) are considered as the ultimate choice in the next-generation high performance energy-storage systems due to their outstanding theoretical energy density (≥500 Wh kg−1). However, the unavoidable dendrite issues and infinite volume change during repeated plating/stripping induce poor electrochemical performance and serious safety issues. Here, we designed and prepared an integrated Oα (O- or O22–)-rich Co3O4 nanoarrays anchored on Ni foam (Oα-Co3O4@NF) scaffold as a stable host for ultra-fast lithium metal infusion. Remarkably, the highly reactive Oα behaves low energy bonding and strong electron affinity, which are further verified by the results of density functional theory, giving rise to high lithiophilicity and inhibiting the dendrites formation effectively. Moreover, the by-product NiO formed on the NF during the calcination process combines with Oα-Co3O4 to display superior dual-wettability toward molten Li. As a result, the Oα-Co3O4@NF electrode achieves a Coulombic efficiency above 99.00% more than 450 cycles at a current density of 1 mA cm−2, and the Oα-Co3O4@NF-Li anode presents a super-long and stable lifetime of 800 h during the repeated plating/striping process. When coupled with a high-loading LiFePO4 cathode, the full cells deliver excellent rate capability and 88.96% capacity retention after 200 cycles under 0.5C.