Guiding Fabrication of Continuous Carbon-Confined Sb₂Se₃ Nanoparticle Structure for Durable Potassium-Storage Performance

Pulverization usually leads to significant solid electrolyte interface (SEI) formation, weak electrochemical contact, and sluggish K⁺-transmission kinetics. These adverse effects limit the K⁺-transfer reversibility, endangering the potassium-storage performance. Reported carbon composite structures are insufficient in effectively solving this issue, exhibiting limited cycling performance. Hence, we fabricated a continuous carbon-confined Sb₂Se₃ nanoparticle composite structure. As expected, this structure achieves a high capacity of 410 mA h g^–1 after 1000 cycles with a capacity decay ratio of 0.07% per cycle. In the full cell, this structure still shows a high energy density of 181.4 Wh kg^–1. Analysis results reveal that the continuous carbon-confined nanoparticle structure can effectively inhibit pulverization, providing continuous SEI, good electrochemical contact, and a fast K⁺-diffusion rate. These advantages provide abundant paths for reversible K⁺ insertion/extraction, accelerate rapid and continuous K⁺ transmission in electrode, and eventually result in highly reversible K⁺ transmission in the repeated cycling process. This work indicates that constructing a continuous carbon-confined nanoparticle structure can effectively inhibit adverse effects caused by pulverization for pursuing durable potassium-storage performance.