Synergistic CNT-mediated interface engineering and cerium doping boost dual-ion storage kinetics of layered manganese oxide

As a promising cathode material for aqueous zinc-ion batteries (AZIBs), layered manganese oxide features high theoretical capacity and low cost. However, its intrinsic semi-conductivity leads to sluggish charge-transfer kinetics, coupled with structural instability triggered by Jahn-Teller distortion. Herein, Ce-doped MnO 2 anchored on carbon nanotubes (Ce-MnO 2 /CNT) was synthesized via an in-situ growth strategy. Specifically, Ce doping induces numerous oxygen vacancies, enlarges the lattice spacing of MnO 2 , and forms robust interfacial chemical bonds with CNTs, thereby synergistically optimizing the electronic structure and ion transport pathways for accelerated reaction kinetics and stability. The Ce-MnO 2 /CNT cathode exhibits substantially enhanced electrochemical performance relative to the un-doped MnO 2 /CNT and pristine MnO 2 . It delivers a high discharge capacity (459.0 mAh g −1 at 0.1 A g −1 ), enhanced rate capability (88.4 mAh g −1 under 3.0 A g −1 ), and robust cycling durability (retaining 82.8% after 300 cycles at 0.3 A g −1 ). Kinetic analyses confirm that Ce doping accelerates ion diffusion and reduces charge transfer resistance. Meanwhile, ex-situ and in-situ characterizations confirm that H + /Zn 2+ dual-ion storage mechanism dominated by H + intercalation/deintercalation. This work proposes a feasible strategy for modulating the electronic structure and interfacial properties of MnO 2 cathodes, offering valuable insights for the pursuit of high-performance AZIBs.