To break the limitation of salt removal capacity of capacitive desalination (CDI), a novel dual-ion hybrid CDI (Di-HCDI) system is proposed which is composed of Na_1.1V₃O_7.9@reduced graphene oxide (NVO@rGO) acting as the sodium ion intercalation electrode while Ag@rGO served as the chloride ion intercalation electrode. Once a direct voltage is applied, the faradaic redox reactions trigger on both electrodes, resulting in sodium ions and chloride ions being removed from the salty electrolyte. NVO exhibits a ribbon structure, having a high sodium intercalation capacity. By coupling with rGO, an ion conductor network is introduced, providing high sodium ion mobility as well as improving the structural stability due to the flexibility of rGO. As a result, the Ag@rGO‖NVO@rGO device demonstrates a superior desalination performance, i.e. ultra-high desalination capacity, rate capability and regeneration. When it was operated in NaCl solution with an initial concentration of 2000 mg L⁻¹ at 1.4 V, the salt removal capacity was 82.2 mg g⁻¹. Remarkably, the charge efficiency of the Ag@rGO‖NVO@rGO device reached 94.4% even in highly concentrated brine, indicating the co-ion effect has been restricted. Benefiting from this, the system proves a Di-HCDI strategy which reveals advances over most of the current CDIs.

Constructing nanostructures with high structural stability and ultrafast electrochemical reaction kinetics as anodes for sodium‐ion batteries (SIBs) is a big challenge. Herein, the robust 2D VS₂/ Ti₃C₂T_x MXene nanostructures with the strong Ti─S covalent bond synthesized by a one‐pot self‐assembly approach are developed. The strong interfacial interaction renders the material of good structural durability and enhanced reaction kinetics. Meanwhile, the enlarged and few‐layered MXene nanosheets can be easily obtained according to this interaction, providing a conductive network for sufficient electrolyte penetration and rapid charge transfer. As predicted, the VS₂/MXene nanostructures exhibit an extremely low sodium diffusion barrier confirmed by DFT calculations and small charge transfer impedance evidenced by electrochemical impedance spectroscopy (EIS) analysis. Therefore, the SIBs based on the VS₂/MXene electrode present first‐class electrochemical performance with the ultrahigh average initial columbic efficiency of 95.08% and excellent sodium‐ion storage capacity of 424.6 mAh g⁻¹ even at 10 A g⁻¹. It also shows an outstanding sodium‐ion storage capacity of 514.2 mAh g⁻¹ at 1 A g⁻¹ with a capacity retention of nearly 100% within 500 times high‐rate cycling. Such impressive performance demonstrates the successful synthesis strategy and the great potential of interfacial interactions for high‐performance energy storage devices.

The use of transition metal oxides to achieve capacitive deionization (CDI) via salt adsorption is based mainly on cation electrochemistry. Activating anionic (oxygen) redox chemistry can enable additional salt adsorption on transition metal oxides, but most conventional lattice oxygen‒metal configurations require high voltages (>4 V) for activation and are prone to lattice oxygen loss. Here, we propose a heterolattice oxygen-mediated redox mechanism to activate oxygen (O_2p) redox at <2 V by constructing a V₂O₅/V₂CO_2p heterostructure. Unlike the synthetic strategy based on excess Li/Na, we develop a barrier strategy based on an oxidative nucleophilic reaction using V₂CF_x as a precursor to induce the formation of heterolattice oxygen in V₂O₅/V₂CO_2p heterostructures. Consequently, ultrahigh CDI performance is achieved, including a salt adsorption capacity of 185.8 mg g⁻¹ at 1.4 V and a salt adsorption rate of 12.1 mg g⁻¹ min⁻¹, which exceed those of reported other faradaic materials. Further mechanistic studies reveal that the induced O_2p electrons that dominate the Fermi level provide an additional pathway for electron movement, activating additional oxygen redox processes and forming a sodium-rich vanadate (Na₄V₂O₇)/V₂CO_2p heterostructure. This strategy provides insights into the development of high-performance CDI materials with oxygen redox based on lattice oxygen‒metal configurations.