Engineering 3D Architecture Electrodes for High-Rate Aqueous Zn–Mn Microbatteries

Increasing development of microelectronic systems and miniature electronic devices greatly boosts the demands for the miniaturization of energy storage devices, especially microbatteries with high energy density and high rate performance. Nevertheless, conventional alkaline (Li, Na, and K) microbatteries suffer from safety and environmental issues owing to the noxious and flammable organic electrolytes, as well as the poor kinetic performance. In this work, a three-dimensional (3D) nanocone array (NCA) architecture-engineered aqueous Zn–Mn microbattery is successfully constructed through highly efficient femtosecond laser scribing and subsequent multistep electrodeposition. Herein, the introduced 3D NCA architecture enables the enhanced electrical conductivity and wettability, an intimate contact with active materials, and the shortened ion diffusion distance between the cathode and anode. Moreover, the unique 3D microstructure is favorable for the excellent conductive framework, the shortened electron transmission path, and remarkable ion transport ability. Besides, quantitative electrochemical kinetic analysis of the 3D Zn–Mn microbattery indicates that a surface capacitive behavior dominates in the process of cycling. With the merits of high areal capacity and superior rate capability, the aqueous Zn–Mn microbattery is believed to be promising in driving portable microelectronic devices and integrated microsystems.