Binder Design in Extrusion-Based 3D Printing of Electrodes: Enhancing Printability and Electrochemical Performance in...

Binder design, encompassing the selection, modification, or engineering of binder materials and their nanostructured architecture, plays a pivotal role in determining the multifunctional performance of electrodes in energy storage devices (ESDs). As 3D printing emerges as an enabling technology for complex, customizable electrode architectures, the binder design becomes the main controllable element, governing printability, manufacturability, and electrochemical performance. In extrusion-based approaches such as direct ink writing (DIW), binder-driven rheology critically influences ink flow, filament stability, and structural fidelity, while fast charge-transfer kinetics and interfacial behavior shape the resulting electrochemical response. This review covers recent advances in binder design strategies that enhance both the printability and performance of 3D printed ESD electrodes, with particular emphasis on the promising transferability of conventional electrode fabrication slurries into 3D printable inks and development of porous hierarchical structures. It further examines how binder chemistry can address persistent challenges in emerging battery systems including pulverization in silicon anodes, dendrite formation in zinc-based systems, low-capacity retention, and limited mass loading. By integrating insights across synthetic, natural, and specialty binder systems, this review highlights the design principles required for next-generation binder materials.