Interface Engineering Enhances Pseudocapacitive Contribution to Alkali Metal Ion Batteries

Increasing the pseudocapacitive contribution has been regarded as an effective means to overcome slow diffusion-limited redox mechanism in electrode materials. Enhanced pseudocapacitive contribution by interface engineering holds huge potential in improving the electrochemical performance of composite electrodes owing to the effective manipulation of ionic transfer kinetics. In this work, the Sb₂S₃@TiO₂ composite with a nitrogen-doped three-dimensional carbon skeleton was designed as the anode for lithium (sodium)-ion batteries (LIBs/SIBs), which delivered significantly enhanced pseudocapacitive contribution. Sb₂S₃ acted as the main contributor of high capacity, while the addition of amorphous TiO₂ suppressed the excessive growth of Sb₂S₃ on the three-dimensional carbon framework and improved the stability of composite electrodes. Moreover, the edge positions of Sb₂S₃ and TiO₂ are abundant. The combination of TiO₂ and Sb₂S₃ eliminated the band gap of the material, greatly improved the electronic conductivity and pseudocapacitance contribution, thus accelerating the reaction kinetics, which verifies by the first-principles calculation results. Benefit from this, the featured anode exhibited ultralong cycle life and improved rate performance, with a specific capacity of 451.5 mA h g^–1 for 200 cycles at 0.5 A g^–1 (LIBs) and 300.5 mA h g^–1 for 1600 cycles at 0.5 A g^–1 (SIBs). This work provides some insights into enhanced pseudocapacitive contribution to multi-battery charge storage by manipulating the interface effect of electrode materials.