Nitrogen-doped carbon encapsulated zinc vanadate polyhedron engineered from a metal-organic framework as a stable anode for alkali ion batteries

In this work, we fabricated vanadium/zinc metal-organic frameworks (V/Zn-MOFs) derived from self assembled metal organic frameworks, to further disperse ultrasmall Zn2VO4 nanoparticles and encapsulate them in a nitrogen-doped nanocarbon network (ZVO/NC) under in situ pyrolysis. When employed as an anode for lithium-ion batteries, ZVO/NC delivers a high reversible capacity (807 mAh g(-1) at 0.5 A g(-1)) and excellent rate performance (372 mAh g(-1) at 8.0 A g(-1)). Meanwhile, when used in sodium-ion batteries, it exhibits long-term cycling stability (7000 cycles with 145 mAh g(-1) at 2.0 A g(-1)). Additionally, when employed in potassium-ion batteries, it also shows outstanding electrochemical performance with reversible capacities of 264 mAh g(-1) at 0.1 A g(-1) and 140 mAh g-1 at 0.5 A g(-1) for 1000 cycles. The mechanism by which the pseudocapacitive behaviour of ZVO/NC enhances battery performance under a suitable electrolyte was probed, which offers useful enlightenment for the potential development of anodes of alkali ion batteries. The performance of Zn2VO4 as an anode for SIBs/PIBs was investigated for the first time. This work provides a new horizon in the design ZVO/NC as a promising anode material owing to the intrinsically synergic effects of mixed metal species and the multiple valence states of V. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

In this study, vanadium/zinc metal-organic frameworks were fabricated to disperse ultrasmall Zn2VO4 nanoparticles and encapsulate them in a nitrogen-doped nanocarbon network. The resulting material, ZVO/NC, demonstrated high reversible capacity and excellent rate performance in lithium-ion batteries, long-term cycling stability in sodium-ion batteries, and outstanding electrochemical performance in potassium-ion batteries. The mechanism by which ZVO/NC enhances battery performance was investigated, offering valuable insights for the development of anodes for alkali ion batteries.