Nature of Bimetallic Oxide Sb₂MoO₆/rGO Anode for High‐Performance Potassium‐Ion Batteries

Abstract

Potassium‐ion batteries (KIBs) are one of the most appealing alternatives to lithium‐ion batteries, particularly attractive in large‐scale energy storage devices considering the more sufficient and lower cost supply of potassium resources in comparison with lithium. To achieve more competitive KIBs, it is necessary to search for anode materials with a high performance. Herein, the bimetallic oxide Sb 2 MoO 6 , with the presence of reduced graphene oxide, is reported as a high‐performance anode material for KIBs in this study, achieving discharge capacities as high as 402 mAh g −1 at 100 mA g −1 and 381 mAh g −1 at 200 mA g −1 , and reserving a capacity of 247 mAh g −1 after 100 cycles at a current density of 500 mA g −1 . Meanwhile, the potassiation/depotassiation mechanism of this material is probed in‐depth through the electrochemical characterization, operando X‐ray diffraction, transmission electron microscope, and density functional theory calculation, successfully unraveling the nature of the high‐performance anode and the functions of Sb and Mo in Sb 2 MoO 6 . More importantly, the phase development and bond breaking sequence of Sb 2 MoO 6 are successfully identified, which is meaningful for the fundamental study of metal‐oxide based electrode materials for KIBs.

Metal chalcogenides for potassium storage

“…Inspired by the existing pioneering work involving graphite, tremendous efforts have been devoted to this area of research. To date, several categories of materials are verified to be effective for potassium storage in terms of anodes, including carbon nanophases (eg, hard carbon, graphite, and heteroatom‐doped carbon), alloy‐type (semi‐)metals (eg, Sn, Bi, Sb, and P), metal oxides (eg, Nb 2 O 5 , SnO 2 , Fe x O, and Sb 2 MoO 6 )/sulfides (eg, MoS 2 , VS 2 , SnS 2 , and Sb 2 S 3 ) and phosphides (eg, FeP, CoP, Sn 4 P 3 , and GeP 5 ), sylvite compounds (eg, KVPO 4 F, K 2 V 3 O 8 , KTi 2 (PO 4 ) 3 , and K x Mn y O z ), metal‐organic composites (eg, Co 3 [Co(CN) 6 ] 2 and K 1.81 Ni[Fe(CN) 6 ] 0.97 ·0.086H 2 O), and pure organic polymers (eg, boronic ester, fluorinated covalent triazine, perylene‐tetracarboxylate, perylenetetracarboxylic diimide, azobenzene‐4,4′‐dicarboxylic acid potassium, 2,2′‐azobis[2‐methylpropionitrile], and poly[pyrene‐ co ‐benzothiadiazole]). However, most carbon materials barely deliver reversible capacities exceeding 300 mAh g −1 despite their excellent electrochemical cyclability.…”

Nature of FeSe2/N‐C Anode for High Performance Potassium Ion Hybrid Capacitor

“…[27] These series of physical and chemical changes will affect the electrochemical performance. [29][30][31][32] Transition metal dichalcogenides (TMDs) have gained comprehensive attention in the field of energy storage due to their unique electrochemical properties, high electrical conductivity, and high capacity. [29][30][31][32] Transition metal dichalcogenides (TMDs) have gained comprehensive attention in the field of energy storage due to their unique electrochemical properties, high electrical conductivity, and high capacity.…”

Free-standing N-doped hollow carbon fibers as high-performance anode for potassium ion batteries

“…In general, the main mechanism of potassium storage in this PIB is adsorption, accompanied by partial intercalation reactions. In addition, the reaction dynamics of the NHCF@NCC electrodes after different cycles were analyzed by EIS [60][61][62]. The pristine NHCF@NCC electrode and the same electrode after the 1 st and 10 th cycles at 500 mA g −1 were recorded, as presented in Nyquist plots (Fig.…”