Cluster Engineering Synergistically Breaks the Kinetics–Stability Trade‐Off in Nickel Ditelluride Cathodes for High‐Performance Rechargeable Aluminum Batteries

ABSTRACT Transition metal chalcogenides (TMCs) used as cathodes for rechargeable aluminum batteries (RABs) are constrained by a kinetic–stability trade‐off: bulk materials suffer from sluggish Al 3+ diffusion, whereas conventional nanosized counterparts improve kinetics but remain vulnerable to structural degradation arising from non‐uniform stress evolution during cycling. Herein, an amino‐polymer‐assisted strategy is developed to fabricate ultrafine NiTe 2 clusters (∼5.5 nm) uniformly anchored on mesoporous carbon matrix (NiTe 2 ‐CL@MHC). By confining NiTe 2 to the cluster scale, the host lattice achieves a homogenized stress distribution, effectively suppressing the pulverization and lattice distortion typical of conventional nanoparticles. Finite element simulations confirm that this cluster‐based architecture alleviates volume strain and mechanical degradation during Al 3+ insertion/extraction. Simultaneously, theoretical calculations reveal an upshifted Ni d ‐band center and intense electronic coupling at the cluster‐matrix interface, lowering the Al 3+ migration barrier to 0.11 eV. Owing to these merits, the NiTe 2 ‐CL@MHC cathode delivers a capacity of 238 mAh g −1 at 0.5 A g −1 and maintains a reversible capacity of 119 mAh g −1 after 3000 cycles at 5.0 A g −1 . This work not only provides a generalizable pathway for stabilizing TMC clusters but also validates the potential of cluster engineering in bridging the gap between atomic‐scale manipulation and advanced nanomaterial design for high‐performance RABs.