Ultrastable High‐Energy On‐Chip Nickel–Bismuth Microbattery Powered by Crystalline Bi Anode and Ni–Co Hydroxide Cathode

Abstract

On‐chip microbatteries (MBs) with excellent electrochemical performance have attracted great attention for applications in miniaturized electronics. However, the lack of strategy for well‐suited integration of microelectrodes with decent mechanical properties and high electrochemical performance in microdevices restricts the development of on‐chip MBs. This work proposes a promising planar nickel–bismuth (Ni//Bi) MB, constructed through the microelectromechanical system‐based fabrication process and facile electrodeposition of Bi anode and Ni 1− x Co x (OH) 2 cathode. Benefiting from the large surface area and effective integration of electrodes, the fabricated Ni//Bi MB achieves a relatively high energy density of 12.3 μWh cm −2 and high stability with 84.44% capacity retention after 1000 cycles. With an attractive fabrication technique and outstanding electrochemical performance, the Ni//Bi MB shows great potential for prospective applications in portable devices/systems.