Metal–Organic Framework-Derived Nitrogen-Doped Cobalt Nanocluster Inlaid Porous Carbon as High-Efficiency Catalyst for Advanced Potassium–Sulfur Batteries

Abstract

Despite high theoretical capacity and earth-abundant resources, the potential industrialization of potassium–sulfur (K–S) batteries is severely plagued by poor electrochemical reaction kinetics and a parasitic shuttle effect. Herein, a facile low-temperature pyrolysis strategy is developed to synthesize N-doped Co nanocluster inlaid porous N-doped carbon derived from ZIF-67 as catalytic cathodes for K–S batteries. To maximize the utilization efficiency, the size of Co nanoparticles can be tuned from 7 nm to homogeneously distributed 3 nm clusters to create more active sites to regulate affinity for S/polysulfides, improving the conversion reaction kinetics between captured polysulfides and K2S3/S, fundamentally suppressing the shuttle effect. Cyclic voltammetry curves, Tafel plots, electrochemical impedance spectroscopy, and density functional theory calculations ascertain that 3 nm Co clusters in S–N–Cos–C cathodes exhibit superior catalytic activity to ensure low charge transfer resistance and energy barriers, enhanced exchange current density, and improved conversion reaction rate. The constructed S–N–Cos–C cathode delivers a superior reversible capacity of 453 mAh g–1 at 50 mA g–1 after 50 cycles, a dramatic rate capacity of 415 mAh g–1 at 400 mA g–1, and a long cycling stability. This work provides an avenue to make full use of high catalytic Co nanoclusters derived from metal–organic frameworks.

Hollow CoS/C Structures for High-Performance Li, Na, K Ion Batteries

“…For CoS/C–PIBs, the peak related to the initial insertion of potassium locates at 1.1 V and the peak attributed to SEI film formation are located at 0.4 V. For all three kinds of batteries, the peak intensity of the SEI film decreases with the increasing number of cycles, indicating that the side reactions such as electrolyte decomposition weaken gradually, which is consistent with the increase in Coulombic efficiency. Owing to different charge–discharge mode, the changes of Coulombic efficiency reflected by CV peak intensity variations are not as obvious as that under the galvanostatic charge–discharge mode ( Ge et al, 2020 ). Besides, the intensity of redox peaks in LIBs is stronger than that in SIBs and PIBs, indicating that LIBs, SIBs, and PIBs show different reaction degrees based on different alkali metal ions.…”

A Low‐Strain Phosphate Cathode for High‐Rate and Ultralong Cycle‐Life Potassium‐Ion Batteries

“…In terms of the working voltage, the KVP nanoruler electrode surpasses most previously reported PIB cathode materials (Figure 3 c). [13, 17, 20, 28, 29, 33–37] …”

“… a) CV and b) charging/discharging profiles of the KVP nanoruler cathode. c) Comparison of working voltages of the KVP nanorulers with previously reported PIB cathode materials (S, [33] Se, [29] 3,4,9,10‐perylene‐tetracarboxylicacid‐dianhydride (PTCDA), [34] poly(pyrene‐ co ‐anthraquinone) (PyAq), [35] K 0.6 CoO 2 , [17] K 0.65 Fe 0.5 Mn 0.5 O 2 , [36] K 3 V 2 (PO 4 ) 3 , [37] K 1.84 Ni[Fe(CN) 6 ] 0.88 ⋅0.49 H 2 O (KNiHCF), [28] K 1.94 Mn[Fe(CN) 6 ] 0.994 ⋅0.08 H 2 O (KMF‐EDTA), [13] and KVPO 4 F [20] ). d) Rate capabilities of the KVP nanorulers, KVP wide nanorulers, and KVP microrods.…”

“…nanoruler electrode surpasses most previously reported PIB cathode materials (Figure 3c). [13,17,20,28,29,[33][34][35][36][37] Figure 3d illustrates the rate property of KVP nanorulers cycled at different current densities.When measured at 0.02, 0.05, 0.1 0.2, 0.5, 1and 2Ag À1 ,average discharge capacities of 80.8, 79.4, 78.0, 75.5, 72.7, 67.6, and 60.8 mAh g À1 can be delivered. Even when ah igh current rate of 5Ag À1 is executed, ad ecent capacity of 54.4 mAh g À1 is still maintained.…”

Recent Progress on Zeolitic Imidazolate Frameworks and Their Derivatives in Alkali Metal–Chalcogen Batteries

“…As a representative work, Yin et al developed a Co nanocluster-inlaid porous carbon derived from a ZIF-67 precursor serving as a sulfur host and catalyst. [204] The Co nanoclusters, with a size of approximately 3 nm, boosted the conversion kinetics between the captured polysulfides and K 2 S 3 /S, thereby restricting polysulfide shuttling. The as-constructed S/N-Co s -C cathode delivered a remarkable capacity of 453 mAh g −1 after 50 cycles at 50 mA g −1 and superior rate capability with a capacity of 415 mAh g −1 at 400 mA g −1 .…”