Towards high-performance microscale batteries: Configurations and optimization of electrode materials by in-situ analytical platforms

The rapid development of miniaturized electronic systems stimulates the demand for microscale power sources. Microscale rechargeable batteries (μRBs) are one promising candidate for the microscale energy storage due to high energy density, long cycling stability, and excellent compatibility with electronic devices. The progress in microscale rechargeable batteries from two-dimensional to three-dimensional configurations are first summarized. The advantage of three-dimensional configurations is extensively discussed. The growing demand for high-energy-density microdevices requires significant improvement of current μRBs, thus making it urgent to obtain an in-depth understanding of electrochemical behaviors in microbatteries. In this perspective, the in-situ/in-operando analytical platforms for efficient investigation of microelectrodes are comprehensively reviewed. Moreover, the design principle of the on-site investigation of microscale batteries is highlighted. Finally, we discuss essential challenges in both device configuration and materials optimization strategies.