Bi Nanosheets on Porous Carbon Cloth Composites for Ultrastable Flexible Nickel–Bismuth Batteries

The use of bismuth (Bi) as an anode material in nickel–metal batteries has gained significant attention due to its highly reversible redox reaction and suitable operating conditions. However, the cycling stability and flexibility of nickel–bismuth (Ni//Bi) batteries need to be further improved. This paper employs a facile electrodeposition technique to prepare Bi nanosheets uniformly grown on a porous carbon cloth (PCC), denoted as Bi-PCC electrodes. The Bi-PCC electrode portrays a specific surface area and good wettability that enable fast charge transfer and ion transport channels. Consequently, the Bi-PCC electrode demonstrates a high specific capacity of up to 297.1 mAh g–1 at 2 A g–1, with a capacity retention of up to 71.5% at 2–40 A g–1 and an impressive capacity retention of 79.9% after 1000 cycles at 2–40 A g–1. More importantly, the flexible rechargeable Ni//Bi battery (denoted as Ni(OH)2-PCC//Bi-PCC) with Bi-PCC as the anode and Ni(OH)2-PCC as the cathode has excellent electrochemical performance. The Ni(OH)2-PCC//Bi-PCC battery boasts a remarkable capacity retention of 93.6% after 3000 cycles at 10 A g–1. Further, the cell presents a maximum energy density of 73.1 Wh kg–1 and an impressive power density of 11.9 kW kg–1.