Tailoring Self-Catalytic N─Co Bonds into Heterostructure Architectures: Deciphering Polytellurides Conversion Mechanism Toward Ultralong-Lifespan Potassium Ion Storage.

Transition metal tellurides (TMTes) are promising anodes for potassium-ion batteries (PIBs) due to their high theoretical specific capacity and impressive electronic conductivity. Nevertheless, TMTes suffer from persistent capacity degradation due to the large volume expansion, high ion-diffusion energy barriers, and the dissolution/shuttle of potassium polytellurides (KTe). Herein, a heterostructured CoTe composite equipped with a self-catalytic center (N-CoTe/LTTC) is developed, exploiting its low-tortuosity tunneling, chemical tunability, and self-catalytic properties to elevate cycling stability to new heights.

Grid-Like Structured Sb@DNC Anode by Self-Sacrificial Etching for Fast and Durable Sodium Storage.

Alloying-type materials are promising anodes for sodium storage due to high specific capacities and appropriate redox potentials, but their practical application is impeded by rapid capacity decay from volume change during sodium ion insertion/extraction. Hence, a dual-type N-doped carbon-confined antimony (Sb) nanoparticle (Sb@DNC, where DNC contains an outer N-doped carbon armor and an inner N-doped grid-like carbon skeleton) anode material is fabricated via a self-sacrificial etching strategy to address this challenge. Specifically, the dual-type N-doped carbon matrix can prevent the agglomeration and precipitation of Sb particles, increase a large number of reactive active sites, alleviate severe volume expansion/contraction, and construct a highly interconnected electron/ion transport network.