Rational Design of Multinary Metal Chalcogenide Bi_0.4Sb_1.6Te₃ Nanocrystals for Efficient Potassium Storage

Abstract

Multinary metal chalcogenides hold considerable promise for high‐energy potassium storage due to their numerous redox reactions. However, challenges arise from issues such as volume expansion and sluggish kinetics. Here, we present a design featuring a layered ternary Bi0.4Sb1.6Te3 anchored on graphene layers as a composite anode, where Bi atoms act as a lattice softening agent on Sb. Benefiting from the lattice arrangement in Bi0.4Sb1.6Te3 and structure, Bi0.4Sb1.6Te3/graphene exhibits a mitigated expansion of 28% during the potassiation/de‐potassiation process and demonstrates facile K+ ion transfer kinetics, enabling long‐term durability of 500 cycles at various high rates. Operando synchrotron diffraction patterns and spectroscopies including in‐situ Raman, ex situ adsorption, and X‐ray photoelectron reveal multiple conversion and alloying/de‐alloying reactions for potassium storage at the atomic level. Additionally, both theoretical calculations and electrochemical examinations elucidate the K+ migration pathways and indicate a reduction in energy barriers within Bi0.4Sb1.6Te3/graphene, thereby suggesting enhanced diffusion kinetics for K+. These findings provide insight in the design of durable high‐energy multinary tellurides for potassium storage.This article is protected by copyright. All rights reserved

Recent advances in rational design for high-performance potassium-ion batteries

“…Some metal telluride materials have also been investigated as anode materials for PIBs. 402–404,571 Park et al 572 designed FeTe 2 –C nanospheres with a yolk–shell structure (Fig. 48a).…”

“…Li et al 573 revealed that the dissolution and shuttle effect of the polytelluride intermediates (K x Te y ) in the electrolyte are responsible for the capacity decay of metal tellurides. Recently, Zhang et al 403 designed layered ternary Bi 0.4 Sb 1.6 Te 3 , in which Bi can be used as a lattice softener for Sb. As displayed in Fig.…”