4D printing for energy storage systems: A transformative manufacturing paradigm

Growing demands in the field of energy storage materials have driven the need for ways of manufacturing more adaptive, efficient, and sustainable systems. This has increased interest in advanced manufacturing technologies that enable both structural programmability, and functional responsiveness. 4D printing (4DP), a step in evolution of additive manufacturing, uses stimuli-responsive smart materials (such as shape memory polymers, hydrogels, nanocomposites, and metal oxides) to fabricate components that are capable of time-dependent dynamic reconfiguration. This study investigates the intersection of 4DP technology and energy storage systems by critically evaluating the materials, processes, and device-centric applications of 4DP in batteries, supercapacitors, and fuel cells. This study categorizes electrochemical storage types, their material requirements, and current synthesis methods, identifying key limitations in energy efficiency, waste, and adaptability. 4DP-compatible materials are thoroughly analyzed in terms of their printability, structural integrity, and functional performance under various stimuli. Multiple case studies demonstrate thermal actuation, shape recovery, and self-healing in energy devices. A comparative analysis was also conducted between 3D printing (3DP) technology and 4DP according to parameters such as energy consumption, material waste, flexibility, and scalability. Current technological barriers identified in the literature include low throughput, complexities in ink formulation, and postprint activation requirements, which are discussed along with emerging solutions. With this review, the authors position 4D printing as a potential alternative manufacturing strategy for energy storage systems, particularly in applications requiring programmable architecture and functional adaptability, while recognizing that substantial technical and scalability challenges remain. • 4D printing enables programmable, morphing energy storage device architectures. • Smart materials like SMPs, hydrogels, and MXenes enhance energy storage functions. • 4DP reduces post-processing waste but faces recycling and scalability challenges. • Comparative analysis shows 4DP improves adaptability over traditional techniques. • Multifunctional electrodes show enhanced performance via stimuli-responsive design.