Co/Zn‐based bimetallic MOF ‐derived hierarchical porous Co/C composite as cathode material for high‐performance lithium‐air batteries

Abstract

Structural optimization and electrocatalyst utilization in air cathodes have been identified as two major factors affecting the overall performance of a lithium-air battery. Herein, a cobalt@porous carbon composite, Co@C (700-1000) was obtained by facile annealing of a Co/Zn-bimetallic metalorganic framework (MOF). In the Co/Zn-MOF, cobalt cluster was used as a precursor of the catalyst and zinc cluster as a sacrificial template to generate meso-and macropores. The lithium-air battery with the assembled Co@C (700-1000) air cathode revealed a specific capacity as high as 4 mAh cm À2 . Furthermore, the battery exhibited high cycling stability up to 67 cycles (limited capacity of 0.5 mAh cm À2 ). The high cell performance can be in relation to the catalytic activity of uniformly disseminated cobalt nanoparticles in the porous carbon matrix and the rapid diffusion and transport of Li + and O 2 owing to the optimized pore-distribution characteristics. Using a bimetallic MOFderived material, this study sheds fresh light on the design of an air cathode for lithium-air batteries.

Electrochemical Performance and Mechanism of Bimetallic Organic Framework for Advanced Aqueous Zn Ion Batteries

“…In addition, two accompanying satellite peaks for the Mn 2p orbit are at positions 655.7 and 643.3 eV. The Zn 2p spectra (Figure b) clearly show Zn 2p 1/2 at 1044.3 eV and Zn 2p 3/2 at 1020.5 eV . The above results show that Zn and Mn elements exist in ZnMn-SQ in the form of bivalent.…”

“…The peaks located at 652.7 and 640.4 eV in the XPS spectrum of Mn 2p correspond to Mn 2p 1/2 and Mn 2p 3/2 , respectively. 40 In addition, two accompanying satellite peaks for the Mn 2p orbit are at positions 655.7 and 643.3 eV. The Zn 2p spectra (Figure 2b) clearly show Zn 2p 1/2 at 1044.3 eV and Zn 2p 3/2 at 1020.5 eV.…”

Hierarchical Integrated Hybrid Structural Electrodes Based on Co‐N/C and Mo‐doped NiCo‐LDH@Co‐N/C Anchored on MX/CF for High Energy Density Fiber‐Shaped Supercapacitor

“…It has been found that all the negative electrodes show typical type IV adsorption-desorption isotherms with an H3 type hysteresis loops within the P/P o range 0.5-1.0 relative pressure, indicating the presence of abundant mesopores (shown in Figure 1h). [38,39] As the amount of Zn increases, the hysteresis loop gets larger indicating, more mesopores formation after the addition of Zn, which leads to increase in the Brunauer-Emmett-Teller (BET) specific surface area (SSA). The SSA was found in increasing order of 128.04, 143.27, 157.30, and 160.71 m 2 g −1 for Co-NP@MX/CF, Co-N/C 0.25 @MX/CF Co-N/C 0.5 @MX/CF, and optimized Co-N/C 1 @MX/CF, respectively.…”

Hydrophobic and Homogeneous Conductive Carbon Matrix for High‐Rate Non‐Alkaline Zinc‐Air Batteries

“…Mesoporous cathodes with a high pore volume have been found to promote O 2 diffusion and improve specific capacity in lithium-air batteries. [25,26] Additionally, the use of non-conductive binders in preparing electrodes with active materials of particle morphology leads to the formation of inactive regions, resulting in non-uniform deposition of discharge products. Therefore, the consistency and continuity of the electrons and ions conductivity of the air cathode is crucial for the homogeneous distribution of discharge products.…”