In-situ dynamic catalysis electrode electrolyte interphase enabling Mg2+ insertion in 2D metal–organic polymer for high-capacity and long-lifespan magnesium batteries

Rechargeable magnesium battery is regarded as the promising candidate for the next generation of high-specific-energy storage systems. Nevertheless, issues related to severe Mg-Cl dissociation at the electrolyte–electrode interface impede the insertion of Mg 2+ into most materials, leading to severe polarization and low utilization of Mg-storage electrodes. In this study, a metal–organic polymer (MOP) Ni-TABQ (Ni-coordinated tetramino-benzoquinone) with superior surface catalytic activity is proposed to achieve the high-capacity Mg-MOP battery . The layered Ni-TABQ cathode, featuring a unique 2D π-d linear conjugated structure, effectively reduces the dissociation energy of Mg x Cl y clusters at the Janus interface, thereby facilitating Mg 2+ insertion. Due to the high utilization of active sites, Ni-TABQ achieves high capacities of 410 mAh/g at 200 mA g −1 , attributable to a four-electron redox process involving two redox centers, benzoid carbonyls, and imines . This research highlights the importance of surface electrochemical processes in rechargeable magnesium batteries and paves the way for future development in multivalent metal-ion batteries.