Synthesis design of interfacial structure for highly reversible lithium deposition

Metallic lithium (Li) is a highly promising anode for high-energy-density batteries. However, irreversible Li deposition and Li dendrite growth during cycling, originated from unstable interface and chemistry disintegration, are the most serious challenges for the Li metal anodes to commercialization. Herein, we propose a sustainable synthesis route to achieve a highly reversible and stable Li anode by constructing a three-dimensional (3D) graphene network host decorated with highly dispersed lithiophilic inorganic matters (Li2O and Li2CO3) and coated with an insulator interphase of boron nitride, termed as BIG. Homogeneous Li plating and bottom-up deposition can be obtained due to the Lewis acid and insulating nature of boron nitride in the BIG architecture. The uniformly decorated inorganic components on 3D graphene network benefit the construction of a robust inorganic-riched solid electrolyte interface, enabling highly reversible Li deposition. Therefore, the free-standing BIG electrode delivers a superior cycliability of 150 cycles at the areal capacity of 3.0 mAh/cm2 with low voltage hysteresis for Li plating/stripping. When coupling with LiFePO4 cathode, the as-assembled full cell can stably operate for over 350 cycles with negligible capacity degradation and a low overpotential of 47 mV. This work provides a convenient and cost-effective method to develop highly stable Li metal anodes by comprehensively regulating the interfacial structure and chemistry.