Strengthened s-p orbital hybridization on selenization interphase for stable lean lithium metal batteries

Rationally designing a lithiophilic layer on the current collector (CC) is essential for realizing the next-generation high energy density of lean lithium metal batteries (LLMBs). However, challenges caused by the nonuniform Li deposition and fragile solid electrolyte interphase (SEI) severely restrict their commercialization. Herein, a lithiophilic Cu₂Se layer is fabricated on commercial Cu CCs (Cu₂Se/Cu) by a facile in-situ selenization approach to fulfill stable and homogeneous Li deposition. The unique s-p hybridization between p_x/p_y orbitals of Li and Se sites triggers electronic structure reconfiguration and forms the abundant lithiophilic interface. Furthermore, the in-situ generated Li₂Se/LiF-rich SEI layer not only enhances the adsorption capability, but also decreases the ionic diffusion barrier. Consequently, The Cu₂Se/Cu based symmetric cell show remarkable cycling stability over 3000 h. The full cell with LiFePO₄ cathode maintains an excellent cycling stability of 88.8 % after 400 cycles at 1C. After pairing with the high-loading sulfur cathodes (6.3 mg cm^-2), the full cell shows a high areal capacity of 4.3 mAh cm^-2 with stable cycling performance at an N/P ratio of 2.6. Therefore, this work highlights the potential of Li-dominant s-p orbital hybridization by incorporating Se sites into commercial Cu CCs for designing high-capacity and cycling reversible LLMBs.