Cell architecture designs towards high-energy-density microscale energy storage devices

The rapid growth of miniaturized electronics has led to an urgent demand for microscale energy storage devices (MESDs) to sustainably power the micro electronic devices. However, most MESDs reported to date have suffered from the limited energy densities and shape versatility compared to conventional large-scale counterparts because of the architectural constraints inherent in microfabrication-based cell manufacturing and cell dimension/structure. This review addresses the cell architecture design for MESDs that can achieve both miniaturization and high energy density. We provide a comprehensive overview of five types of cell architectures of MESDs and their fabrication techniques. In addition, to enable practical applications of MESDs, several cell design approaches are presented with the aim of minimizing the inactive parts of the cell and maximizing the performance metrics of MESDs. Finally, we discuss development direction and outlook of MESDs with a focus on materials chemistry, energy-dense electrochemical systems, and cell performance normalization, which will help to expand their applications and manufacturing scalability.