Controllable 3D Porous Ni Current Collector Coupled with Surface Phosphorization Enhances Na Storage of Ni<sub>3</sub>S<sub>2</sub> Nanosheet Arrays
Xiaoyong Fan, Ruibo Sun, Yongqiang Zhu, Shuai Zhang, Lei Gou, Li Lü, Lin Li
Abstract
Abstract 3D porous Ni is fabricated via an easily scalable electroless plating method using a dynamic template formed through in‐situ hydrogen bubbles. The pore size in the range of several micrometers is controllable through adjusting the Ni 2+ depositing rate and hydrogen bubbles releasing rate. The Ni 3 S 2 nanosheet arrays anode is then grown on the unique 3D porous Ni current collector followed by subsequent surface phosphorization. The tremendous interconnected pores and rich voids between the Ni 3 S 2 nanosheet arrays cannot only provide rapid transferring channels for Na + , but also accommodate volumetric changes of the Ni 3 S 2 electrode during cycling, guaranteeing the integrity of the active material. In addition, the surface phosphorized layer enhances the electronic conductivity through providing an electron transport highway along the 3D Ni 3 S 2 , NiP 2 layer, and 3D porous Ni current collector, and simultaneously stabilizes the electrode/electrolyte interphase as a protecting layer. Because of these merits, the phosphorized 3D porous Ni 3 S 2 (3D P‐Ni 3 S 2 ) electrode is capable of delivering an ultra‐stable capacity of 387.5 mAh g −1 at 0.1 A g −1 , and a high capacity retention of 85.3% even at a high current density of 1.6 A g −1 .