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.