Zn-ion batteries have been considered as one of the most promising grid storage devices due to their high energy densities,high safety,and low cost.However,the Zn anode suffers dendrite growth,hydrogen evolution and surface pas-sivation,resulting in low coulombic efficiency,low Zn utilization,and poor cyclability.In this work,PbSn alloy is firstly electrodeposited in the self-prepared three-dimensional(3D)porous Cu,then a Zn layer is electrodeposited on it,finally the partial Zn layer on outer pores is replaced by PbSn alloy,which will transform into PbSO4 in ZnSC4-based electrolyte,and a Zn electrode with 3D porous structure and zincophile gradient is achieved 3D Cu@PbSn@Zn@PbSn(3D Cu@PSZPS).The 3D porous structure can provide high specific area,small and uniform current distribution,as a result enhance Zn plating capacity,inhibit Zn dendrites growth,hydrogen evolution and passivation.The PbSn alloy layer in inner pores can induce Zn plating from inner to outer pores,inhibit dendrites growth;high hydrogen evolution overpotential feature of Pb and Sn can inhibit hydrogen evolution,and also inhibit the passivation caused by increase of pH value.This modification strategy effec-tively circumvents the inherent limitations associated with solely relying on a single strategy.Therefore,this electrode demonstrates excellent electrochemical performance.It can stably cycle for more than 900 times at 5 mA·cm-2,1 mAh·cm-2 with a high first coulombic efficiency of 99.66％,low first nucleation potential of 16.4 mV.The symmetrical cell assembled using this electrode can stably cycle for more than 700 h.The MnO2‖3D Cu@PSZPS full cell shows a high reversible specif-ic capacity of 238.7 mAh·g-1 at 0.3 A·g-1 and a capacity retention of 79.4％over 300 cycles,and can be stably cycling more than 2000 times under the current density of 1.8 A·g-1.
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