Lithium-induced graphene layer containing Li3P alloy phase to achieve ultra-stable electrode interface for lithium metal anode

Uncontrolled growth of lithium dendrite will lead to low Coulombic efficiency and poor cycle stability, which hinders the commercialization of lithium metal batteries. Herein, a novel modified lithium anode with reduced graphene oxide conductive network containing trace lithiophilic phosphorus (P-rGO/Cu) is prepared by electrospraying technique combined with heat treatment process. The rGO layer has a concave and undulating conductive structure, which can significantly improve the effective electrical contact between lithium metal and the current collector, speed up the kinetics of interfacial electron transport and reaction, and improve the resistance of the negative electrode to the internal stress caused by volume change of the lithium, which is advantageous for the stability of the SEI film. The extremely small and uniformly distributed red phosphorus element avoids the volume change caused by lithiation to the maximum extent. Lithiophilic two-phase compound Li3P obtained by alloying P with Li can directionally induce the homogeneous nucleation and dense deposition of lithium metal, address the issue of lithium dendrites and extend the cycle life of the batteries. The obtained P-rGO/Cu exhibits excellent electrochemical performance with an average Coulombic efficiency (CE) of 98% at a current density of 1 mAcm(-2) for 400 cycles, and the capacity retention rate of the full cell matched with lithium iron phosphate (LFP) is 83% after 400 cycles at 1C.

Automated summary

In this study, a modified lithium anode with reduced graphene oxide conductive network and trace lithiophilic phosphorus was prepared to address the issue of lithium dendrites in lithium metal batteries, improving cycle life and Coulombic efficiency. The obtained P-rGO/Cu exhibited excellent electrochemical performance.