A NiCo bimetallic hydroxide electrode-based flexible Ni//Zn battery with smart electrochromic function for visually monitoring battery residual electricity

Flexible battery with a smart electrochromic function of changing color in the electrochemical process reveals great application potentials in the field of intelligent electronics. However, Ni//Zn battery with an electricity visual alerting function has seldom been reported by now. Herein, we designed a flexible Ni//Zn battery, assembled by the NiCo bimetallic hydroxide/Ni/indium tin oxide (NiCo BH/Ni/ITO) flexible electrode with an electrochromic feature. By optimizing the thickness of the middle Ni layer, the NiCo BH/Ni/ ITO electrode shows a coloration efficiency of 59.89 cm(2) C-1 and a capacity of 7.15 mu A h cm(-2) at a current density of 0.1 mA cm(-2). Correspondingly, the flexible electrochromic Ni//Zn battery shows a high energy density of 12.69 mu W h cm(-2) at a power density of 160 mu W cm(-2), outperforming those of transparent flexible supercapacitors and electrochromic batteries reported in literatures. Moreover, the flexible electrochromic Ni//Zn battery displays reversible color change during charging and discharging processes, rendering it a novel function to monitor the battery residual electricity by visual inspection.

Automated summary

This article introduces a flexible battery with a smart electrochromic function and designs a Ni // Zn battery with an electricity visual alerting function. The battery has a high energy density and reversible color change, allowing for visual monitoring of the battery's residual electricity.