An oxygen vacancies-enriched dual-phase bismuth oxide heterostructure derived from metal-organic framework enabling advanced nickel bismuth batteries

Abstract

In this work, an oxygen vacancies (O_v)-enriched heterostructure was prepared, consisting of a monoclinic (mcl) Bi₂O₃ and a tetragonal (tetr) Bi₂O₃ both derived from Bi-metal–organic framework (MOF). At the same time, the first-principle calculation based on density function theory (DFT) was utilized to prove the advantages of the mcl/tetr-Bi₂O₃ heterostructure. The O_v can narrow the band gap and increase the conductivity, carbon skeleton is able to retard the volumetric expansion and the heterostructure can facilitate the interfacial charge transfer. Therefore, mcl/tetr-Bi₂O₃ electrode delivers a high specific capacity of 1446F g⁻¹ (3.0F cm⁻²) at 1 A/g. Nickel-bismuth (Ni//Bi) batteries were prepared using NiCoLDH as positive electrodes. Its aqueous Ni//Bi battery exhibits a high specific capacity as well. The assembled all-solid-state Ni//Bi battery shows high power density and energy density. In particular, the flexible Ni//Bi battery can accommodate bending, unfolding enormous potential for application.