Graphite intercalation compounds (GICs) based multi-functional interface layer toward highly reversible Zn metal anodes

Abstract

Aqueous zinc-ion batteries (ZIBs), the next promising energy technology with outstanding specific capacity, environmental friendliness, and safety, suffer from the dendritic growth and corrosion of Zn anode along with the release of hydrogen. To solve these issues, the graphite intercalation compounds of molybdenum chloride (MoCl5 − GICs) are used as multi-functional interface layers to protect Zn anodes, inhibiting the parasitic reaction to improve the Coulombic efficiency (CE) of ZIBs. The MoCl5 − GICs-coated Zn (Zn@MGs) exhibits the uniform deposition of Zn2+ ions and enhances the transmission of Zn2+ ions, given that the interfacial protection of MoCl5 − GICs possesses high transference number of Zn2+ ions (0.316), good ionic conductivity (9.45 × 10−4 S cm−1), and low desolvated activation energy (1.88 kJ mol−1). Consequently, the symmetric Zn@MGs cell shows an excellent cycling stability for 2000 h at a current density of 1 mA cm−2 within an areal capacity of 1 mAh cm−2. And it also delivers a long lifespan of 1300 h cycling at a high current density of 5 mA cm−2. Paired with a NaV3O8·1.5H2O (NVO) cathode, the Zn@MGs‖NVO full cell exhibits a splendid capacity retention of 63.8 % after 3000 cycles at 5 A g−1. Therefore, the strategy of constructing multi-functional interface layer is a valuable method to facilitate the development of ZIBs.