A Liquid Metal Microdroplets Initialized Hemicellulose Composite for 3D Printing Anode Host in Zn‐Ion Battery

Maintaining a steady affinity between gallium‐based liquid metals (LM) and polymer binders, particularly under continuous mechanical deformation, such as extrusion‐based 3D printing or plating/stripping of Zinc ion (Zn2+), is very challenging. Here, an LM‐initialized polyacrylamide‐hemicellulose/EGaIn microdroplets hydrogel is used as a multifunctional ink to 3D‐print self‐standing scaffolds and anode hosts for Zn‐ion batteries. The LM microdroplets initiate acrylamide polymerization without additional initiators and cross‐linkers, forming a double‐covalent hydrogen‐bonded network. The hydrogel acts as a framework for stress dissipation, enabling recovery from structural damage due to the cyclic plating/stripping of Zn2+. The LM‐microdroplet‐initialized polymerization with hemicelluloses can facilitate the production of 3D printable inks for energy storage devices. The steady affinity between gallium‐based liquid metals and polyacrylamide is successfully fabricated by a strategy that uses shear mixed EGaIn microdroplets as initiator for free radical polymerization. The resultant polyacrylamide‐hemicellulose/EGaIn microdroplets hydrogel possesses shear thinning, self‐healing capabilities, and electrical conductivity. It is used as a multifunctional ink to 3D‐print self‐standing scaffolds and anode hosts for Zn‐ion batteries which shows high durability.