A New Metalgel Current Collector for Simultaneous Rapid and Stable Zinc Electrochemistry

ABSTRACT Achieving both high‐rate capability and long‐term cycling stability in zinc anode remains challenging due to the fundamental trade‐off. Fast kinetics require maximum interfacial area for charge transfer, while stability demands minimal zinc/electrolyte contact to suppress parasitic reactions and dendrite growth. However, in previous studies, zinc deposited at the electrode/electrolyte interface, leading to limited lifetimes (≤ 1200 h at a utilization ratio of ≥ 60%) and high overpotentials (≥ 480 mV at 50 mA·cm ⁻² ). Here, we design a new metalgel current collector to effectively resolve the above limitation. The metalgel comprises a biphasic gallium–indium–zinc continuum immobilized within a 3D polymer network, establishing both ion and electron conduction pathways that maximize the electrochemically active interface. The biphasic gallium–indium–zinc contains solid metallic zinc dispersed within the liquid gallium–indium–zinc alloy phase, enabling inward zinc deposition/stripping via a reversible dissolution–precipitation alloying process. This inward‐deposition/stripping minimizes zinc/electrolyte contact and suppresses parasitic reactions and dendrite formation, enabling zinc anodes to achieve over 4300 h of stable cycling at 80% zinc utilization ratio and maintain only 156.6 mV overpotential at an ultrahigh current density of 100 mA·cm ⁻² . By decoupling interfacial kinetics from interfacial instabilities, this work presents a new paradigm for high‐performance metal batteries.