Three-Dimensional Microbatteries beyond Lithium Ion

Ubiquitous implementation of microelectronics in microelectromechanical systems requires stable power supplies and necessitates development of on-chip miniature power sources, such as microbatteries. However, conventional thin-film batteries exhibit limited surface area and sluggish diffusion kinetics with insufficient energy and power density. In contrast, three-dimensional beyond-lithium (e.g., sodium, zinc, aluminum) battery architectures can significantly enhance the areal energy and power and meanwhile maintain the low-cost mass production. Despite this, the future of beyond-lithium systems is being questioned as they each present shortcomings. In this Perspective, we discuss scientific advancements in reaction kinetics control, electrochemical stability improvements, and reaction mechanism understanding in three-dimensional beyond-lithium battery systems and call for intensive research efforts to address the challenges and develop strategies that can pave the way toward their commercialization.