3D printed lithium-ion batteries: An in-depth examination of the advancements in flexibility and stand-alone capability

Additive manufacturing techniques (3D printing) provide a promising solution to the complicated, expensive, and material-wasting traditional fabrication process for lithium-ion batteries (LIBs). LIBs are known for their high energy and power density, but the complex electrode architectures limit their practical applications in flexible and wearable devices. 3D printing technology allows the controllable fabrication of complex, flexible, and free-standing 3D architecture with computational stimulation, computer-aided design modeling, and machine learning, which can significantly enhance the performance of LIBs. This article reviews recent developments in 3D printing technology for the fabrication of LIBs, including printing electrode materials of different architectures, electrolyte suitability, rheological properties of inks, and their performance. The review also highlights the controllability of 3D printing on the architecture, such as interdigitated-thickness aligned structure, dimensionality, porosity, and interconnectivity of structures with the help of pre-patterned designs by CAD modeling. To overcome challenges and explore future applications, a detailed review of the intrinsic and extrinsic properties of the material, existing 3D printing techniques with their pros and cons, and their adaptability for practical applications is necessary. Finally, the challenges and possible outcomes for real-time applications of 3D printed LIBs are summarized.