Strongly Coupled Interfacial Engineering Inspired by Robotic Arms Enable High‐Performance Sodium‐Ion Capacitors

Interfacial coupling strategy has allured extensive attention for the possibility to endow active electrode materials with superior performance. However, the design of strong coupling engineering with interfacial evolution during electrochemical processes is very challenging. Herein, inspired by the powerful robotic arms and density functional theory calculations, multiple functional groups identified with intense affinity to V atom are successfully grafted on carbon nanotubes (CNTs), thereby in situ building robust interfacial bonds (VOC and VC) to tightly anchor VS4 particles. The largely decreased band gaps and energy barriers show the fortified conductivity of VS4‐CNT heterostructure. Besides, the spacial confinement effect induced by interfacial linkages substantively enhances the mechanical properties to inhibit structural collapse, and restrains the dissolution of polysulfides as verified by molecular dynamics simulations, thus prolonging life span. Excellent energy density of 105.5 Wh kg–1 can be delivered after assembling full sodium‐ion capacitors (activated carbon//VS4‐CNT). Significantly, the reversible interfacial bonds confirmed by various ex situ characteristics during discharge/charge processes hold the key to remarkable sodium storage ability and prominent initial coulombic efficiency. More impressively, strong interfacial coupling effect can establish synergistic soft‐rigid integrated solid‐electrolyte interphase film, which is conducive to elevating the electrochemical performance of electrodes, convincingly constructing advanced sodium‐ion capacitors. Strongly coupled interfaces are systematically exploited in this article. Directional design of interfacial bonding engineering and relative evolution during electrochemical processes are elucidated clearly, offering guidelines to construct advanced anodes for high‐performance sodium‐ion capacitors.