摘要
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•A synergistic triple-action Bi2Se3/Sb2Se3@NC@G electrode is used as anodes for potassium-ion battery.•The triple action design, including p-n junction, bond softening, and dual confinement, maximize the potassium-ion storage.•Multi-morphological heterostructure can not only enhance the conductivity but also facilitates electrolyte infiltration.•The Bi2Se3/Sb2Se3@NC@G electrode exhibits a reversible capacity up to 580 mAh/g at 50 mA/g.•The Bi2Se3/Sb2Se3@NC@G electrode demonstrates a high capacity of 310 mA h/g after 5000th cycles at 500 mA/g.
Synergistic effects could significantly improve slow redox kinetics and structural pulverization of electrodes in potassium ion batteries (PIBs); however, the performance of single synergistic designs is limited. Multi-synergistic composite, shaped by a blend of factors, substantially boosts performance, yielding outcomes that surpass single synergistic coupling design. Herein, we develop a Bi2Se3/Sb2Se3@NC@G electrode that integrates three key features for enhanced potassium-ion storage: p-n junctions enhance electron transfer through internal electric fields, dual confinement prevents K2Se dissolution into the electrolyte, and lattice softening in the Bi-Sb alloy relieves stress during potassium ion insertion/extraction. These multi-synergistic effects enable the heterostructure to exhibit superior electrochemical performance in potassium-ion batteries.The Bi2Se3/Sb2Se3@NC@G electrode demonstrates notable capacity of 640 mA h g-1 at current density of 50 mA g-1, achieving 95.5 % of its theoretical capacity, maintain stable capacity of 310 mA h g−1 after 5000 cycles at current density of 0.5 A/g with 0.002 % per cycle degradation, and exhibits the fastest rate capability up to 10 A/g (172 mA h g−1). Furthermore, potassium ion hybrid capacitor (PIHC) can achieve a high energy density of 118 Wh kg−1 and a power density of 5200 W kg−1, and full cell shows an attractive energy density of 97 Wh kg-1 and a stable performance after 250 cycling number under 1 A g-1. This study proposes an effective strategy that employs multiple synergistic coupling designs to maximize potassium-ion storage capacity, achieving a breakthrough in extending battery lifecycle.