<p>Metal-ion batteries, particularly lithium-ion batteries, are increasingly used to simulate biological electrical signals due to their high energy density and stability, which are vital for advancing biosensors and biomedical devices. This review explores their application in mimicking biological systems. It begins by outlining the fundamental properties of these batteries, then discusses the critical role of biological electrical signals. The paper highlights specific applications in devices such as neural interfaces and cardiac pacemakers, emphasizing their advantage of enabling continuous signal transmission. Key technical challenges—such as biocompatibility, miniaturization, and long-term stability—are addressed alongside potential solutions. Future directions include developing new materials, creating multifunctional integrated devices, and fostering interdisciplinary collaboration. By summarizing current progress and prospects, this review aims to serve as a comprehensive reference for the application of metal-ion batteries in biosimulation technologies.</p>