Bimetallic zeolite imidazolate framework for enhanced lithium storage boosted by the redox participation of nitrogen atoms

Abstract

In this work, a bimetallic zeolitic imidazolate framework (ZIF) CoZn-ZIF was synthesized via a facile solvothermal approach and applied in lithium-ion batteries. The as-prepared CoZn-ZIF shows a high reversible capacity of 605.8 mA h g −1 at a current density of 100 mA g −1 , far beyond the performance of the corresponding monometallic Co-ZIF-67 and Zn-ZIF-8. Ex-situ synchrotron soft X-ray absorption spectroscopy, X-ray diffraction, and electron paramagnetic resonance techniques were employed to explore the Li-storage mechanism. The superior performance of CoZn-ZIF over Co-ZIF-67 and Zn-ZIF-8 could be mainly attributed to lithiation and delithiation of nitrogen atoms, accompanied by the breakage and recoordination of metal nitrogen bond. Morever, a few metal nitrogen bonds without recoordination will lead to the amorphization of CoZn-ZIF and the formation of few nitrogen radicals.

Recent advances in the synthesis of monolithic metal-organic frameworks

“…Metal-organic frameworks (MOFs), which are selfassembled via coordination bonds between the metal ions or clusters and organic ligands, are emerging as a class of fascinating porous organic-inorganic hybrid crystal materials [1,2]. They exhibit fascinating physicochemical characteristics, including ultrahigh specific surface area, abundant active sites, permanent porosity, and diverse topological structure [3,4], making them potentially applicable in the fields of adsorption/separation, sensing, supercapacitors, drug delivery, functional peptidomics, and catalysis [5][6][7][8][9][10][11]. To date, majority of the reported MOFs are polydisperse microcrystalline powders.…”

Rational Design of a ZIF‐67/Cobalt‐Glycolate Heterostructure with Improved Conductivity for High Cycling Stability and High‐Capacity Lithium Storage

“…[36] While for the other three electrodes, the presence of ZIF-67 facilitates the cycling stability due to no significant change in structure during charge and discharge. [37] Therefore, a stable SEI film gradually forming on the surface of ZIF-67 benefit for stability during the long cycle. [38] In addition, the capacity retention of four electrodes after 100 cycles is 108, 85, 81 and 79 %, respectively for ZIF-67, Co-glycolate/ZIF-67-60, Co-glycolate/ZIF-67-80, and Co-glycolate.…”

“…Therefore, Co‐glycolate would suffer from long and slow activation process companying with mechanical degradation and Co–O bonds break/regenerate, resulting in the formation of undesired continuous SEI film, leading to capacity fading [36] . While for the other three electrodes, the presence of ZIF‐67 facilitates the cycling stability due to no significant change in structure during charge and discharge [37] . Therefore, a stable SEI film gradually forming on the surface of ZIF‐67 benefit for stability during the long cycle [38] .…”

Water-based routes for synthesis of metal-organic frameworks: A review

“…Furthermore, the content of Co and Zn in the CoZn-ZIF-8 can be effectively tuned by controlling the amounts of Co and Zn precursors. However, some issues still require further studies, such as the mechanism of inserting Co into Zn-ZIF-8 crystal and the random distribution or aggregation of a certain metal over the metal node [1,97].…”