In Situ Growth of CoS₂/ZnS Nanoparticles on Graphene Sheets as an Ultralong Cycling Stability Anode for Potassium Ion Storage

Abstract

Metal sulfides are promising anodes for potassium-ion batteries (PIBs) due to their high theoretical capacity and abundant active sites; however, their intrinsic low conductivity and poor cycling stability hampered their practical applications. Given this, the rational design of hybrid structures with high stability and fast charge transfer is a critical approach. Herein, CoS 2 /ZnS@ rGO hybrid nanocomposites were demonstrated with stable cubic phases. The synergistic effect of the obtained bimetallic sulfide nanoparticles and highly conductive 2D rGO nanosheets facilitated excellent long-term cyclability for potassium ion storage. Such hybrid nanocomposites delivered remarkable ultrastable cycling performances in PIBs of 159, 106, and 80 mA h g −1 at 1, 1.5, and 2 A g −1 after 1800, 2100, and 3000 cycles, respectively. Moreover, the fullcell configuration with a perylene tetracarboxylic dianhydride organic cathode (CoS 2 /ZnS@rGO∥PTCDA) exhibited a better electrochemical performance. Besides, when the CoS 2 /ZnS@rGO nanocomposites were applied as an anode for sodium-ion batteries, the electrode demonstrated a reversible charge capacity of 259 mA h g −1 after 600 cycles at 2 A g −1 . In situ X-ray diffraction and ex situ high-resolution transmission electron microscopy characterizations further confirmed the conversion reactions of CoS 2 /ZnS during insertion/ desertion processes. Our synthesis strategy is also a general route to other bimetallic sulfide hybrid nanocomposites. This strategy opens up a new roadmap for exploring hybrid nanocomposites with feasible phase engineering for achieving excellent electrochemical performances in energy storage applications.

Anchoring Metal‐Organic Framework‐Derived ZnTe@C onto Elastic Ti3C2Tx MXene with 0D/2D Dual Confinement for Ultrastable Potassium‐Ion Storage

“…We also compared the long-term cycling performance of ZCT with other reported transition metal chalcogenides-based anode materials at a fixed current density of 1.0 A g −1 , as Figure 2e shows. [10][11][12][13][14][15][16][17]19] Our ZCT exhibited the highest specific capacity and the most extended cycle number, demonstrating its excellent cyclability. In addition, all the cyclability results implied the significant synergistic effect between ZC and Ti 3 C 2 T x .…”

“…[7,8] In this circumstance, developing advanced KIB anode materials with high capacity and favorable K + diffusion remains a significant challenge. Recently, transition metal dichalcogenides, such as oxides, [9] sulfides, [10][11][12][13][14][15] selenides, [16,17] and tellurides, [18][19][20][21][22] have been proposed for K + storage because they have high theoretical capacities. Compared to the oxide, sulfide, and selenide counterparts, transition metal tellurides (TMTs) exhibit several appealing advantages: higher conductivity for quick electron mobility, larger lattice spacings for enhanced K + diffusion, higher density for improved volumetric capacities, and metallic thermal conductivity for adequate joule heat transport during cycling.…”

Prussian Blue Analogue‐Derived ZnO/ZnFe2O4 Core‐Shell Nanospheres as High‐Performance Anodes for Lithium‐Ion and Potassium‐Ion Batteries

“…And when b =0.5, diffusion behavior controls the diffusion of potassium ions. As depicted in Figure 6(g), the b value of anodic and cathodic peaks for ZnO/ZnFe 2 O 4 electrode are 0.791 and 0.635, respectively, which proves that the diffusion of potassium ions in this electrode is controlled by the capacitive behavior and the diffusion behavior [70] . The capacitive contribution of S450‐5 can reach 68.4 % at 0.6 mV s −1 , as illustrated in Figure 6(h).…”

“…As depicted in Figure 6(g), the b value of anodic and cathodic peaks for ZnO/ZnFe 2 O 4 electrode are 0.791 and 0.635, respectively, which proves that the diffusion of potassium ions in this electrode is controlled by the capacitive behavior and the diffusion behavior. [70] The capacitive contribution of S450-5 can reach 68.4 % at 0.6 mV s À 1 , as illustrated in Figure 6(h). The capacitance contribution ratios are 48.8 %, 56.6 %, 60.8 %, 68.4 %, 73.4 %, 75.4 %, and 94.2 % at scan rates from 0.1 to 2 mV s À 1 , as Figure 6.…”

Richly electron-deficient BCxO3−x anodes with enhanced reaction kinetics for sodium/potassium-ion batteries

“…Some other strategies for promoting the sodium/potassium storage properties also have been reported, including the construction of a unique carbon nanoarchitecture to shorten the diffusion distance of ions and electrons, 19,[38][39][40][41][42][43] and the expansion of the interlayer space of graphite planes to permit speedy Na + and K + transportation. [44][45][46][47][48] Song et al 49 designed hollow carbon nanocages as the anodes for PIBs, demonstrating excellent cyclability due to the strain relaxation of a hollow cage-like structure during K + insertion/extraction. Recently, Huang et al 50 reported a series of hollow carbon nanocages towards long cycle lifespan SIBs, which exhibit excellent rate performance.…”