One-step hydrothermal synthesis of CoNi bimetallic phosphide nanoflowers for high-performance quasi-solid-state zinc-ion batteries

Authors：Fu, Tianyu; Tong, Xin; Zhou, Yang; Wu, Dajun; Xiong, Dayuan^*; Xu, Shaohui; Wang, Lianwei^*; Chu, Paul K.

Source：Journal of Alloys and Compounds, 2022, 918: 165734.

DOI：10.1016/j.jallcom.2022.165734

• Bimetallic phosphide
• Nanoflowers
• Quasi-solid electrolyte
• Synergistic effects
• Zn-ion battery

Nickel-cobalt bimetallic phosphide (CNP) samples with a flower-like nanosheet morphology are prepared on nickel foam by a simple one-step hydrothermal method to form the cathodes in zinc-nickel batteries. The electrode materials possess not only synergistic properties rendered by nickel and cobalt, but also high theoretical specific capacity and electronic conductivity of transition metal phosphide. The quasi-solid-state batteries assembled with the phosphide electrode, zinc sheet, and hydrogel electrolyte are assessed in alkaline media. The flexible Zn-CNP battery shows an areal capacity of 3.75 mA h cm(-2) at a high current density of 50 mA cm(-2) and retains 93% of its capacity after 2000 cycles (at 80 mA cm(-2)). Furthermore, the quasi-solid-state battery continues to function despite being bent at different angles or after puncturing. The results reveal a novel strategy to design bimetallic phosphide electrodes in zinc-ion batteries for flexible and wearable applications.