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.