3D Printing for Energy Storage Devices: Advances, Challenges, and Future Directions

3D printing (3DP) has emerged as a transformative technology for the fabrication of electrochemical energy storage devices (EESDs), offering unprecedented advantages in design freedom, shape conformality, and material versatility. Unlike previous reviews that narrowly focus on specific materials or device types, this review offers a comprehensive and integrative perspective on the role of 3DP across the full architecture of EESDs, including batteries, supercapacitors, and fuel cells. Recent advances are highlighted in ink formulation strategies tailored for electrochemical functionality, advanced printing techniques enabling microscale precision and structural complexity, and the integration of printed components into functional devices. In discussing future directions, particular emphasis is placed on artificial intelligence (AI)-guided hybrid 3DP approaches that enable the simultaneous use of multiple materials and printing methods within a single process, facilitating the creation of customizable, multifunctional, and shape-adaptable EESDs. By outlining key opportunities and ongoing challenges, this review aims to provide a comprehensive roadmap for the future development of 3D-printed electrochemical energy storage technologies.