Lithiophilic bimetallic selenides in frameworks enable excellent lithium-ion conduction solid electrolyte interphase for high-performance lithium metal batteries

Abstract

Lithium-metal batteries, with their extremely high energy density, have become a popular choice for future energy storage batteries. However, in the process of long-term use, the anode of the lithium metal battery will produce a large number of lithium dendrites, leading to safety problems with the battery; so far, it is difficult to be used on a large scale. In this paper, a lithiophilic framework modified with bimetallic selenides, Cu1.8Se and NiSe2, is fabricated by a simple plating method and subsequent selenization process. Due to the fact that two selenides on the Cu1.8Se–NiSe2@Ni foam framework have excellent lithiophilic properties and have undergone a cation exchange reaction with lithium to produce Li2Se with excellent lithium-ion conductivity at the solid electrolyte interface, the corresponding half-cell achieves a coulombic efficiency of 97.8% and maintains 180 cycles. Similarly, the corresponding symmetrical cell displays outstanding cycle stability for nearly 1000 h with a lithium amount of 5 mAh cm−2 at a current density of 1 mA cm−2. Lastly, a full cell assembled with LiFePO4 (material load of 11.5 mg cm−2) as cathode and Li–Cu1.8Se–NiSe2@Ni foam as anode displays superior long-term cycling (300 cycles at a rate of charge/discharge of 0.5C) and rate performance.