CoS Quantum Dot Nanoclusters for High‐Energy Potassium‐Ion Batteries

Abstract

Potassium-ion batteries (PIBs) are a promising alternative to lithium-ion batteries because potassium is an abundant natural resource. To date, PIBs are in the early stages of exploration and only a few anode materials have been investigated. This study reports a cobalt sulfide and graphene (CoS@G) composite as anode electrode for PIBs for the first time. The composite features interconnect quantum dots of CoS nanoclusters uniformly anchored on graphene nanosheets. The coexistence of CoS quantum dot nanoclusters and graphene nanosheets endows the composite with large surface area, highly conductive network, robust structural stability, and excellent electrochemical energy storage performance. An unprecedented capacity of 310.8 mA h g −1 at 500 mA g −1 is obtained after 100 cycles, with a rate capability better than an equivalent sodium-ion batteries (SIBs). This work provides the evidence that PIBs can be a promising alternative to SIBs, especially at high charge-discharge rates. The development of the CoS@G anode material also provides the basis of expanding the library of suitable anode materials for PIBs.

Mild‐Temperature Solution‐Assisted Encapsulation of Phosphorus into ZIF‐8 Derived Porous Carbon as Lithium‐Ion Battery Anode

“…A general strategy is to physically deposit RP in the carbon hosts via an evaporation/condensation process. [ 5–19 ] Note that a necessary high temperature of 500–900 °C is commonly applied in order to ensure the conversion of the bulk RP into the gas phase. In this process, RP sublimates and diffuses in the carbon hosts and finally form a carbon/RP composite.…”

“…[ 5 ] Moreover, the unstable, toxic, and flammable white phosphorus will also generate accompanied with the evaporation/condensation process, generally requiring further annealing thereafter washing with toxic CS 2 . [ 5–19 ] Recently, a solution‐processed encapsulation method has been developed to facilitate the formation of RP nanoparticles inside MWCNTs and meanwhile allow the easy removal of the external phosphorus anchored on the outer wall of MWCNTs because this solution‐based process avoids the formation of crystalline RP, and finally the phosphorus@MWCNTs hybrids exhibited a significantly improved cycling stability. [ 20 ]…”

“…Ideally, porous carbon hosts not only provide enough vacant space to confine RP, but also ameliorate electrical conductivity. So far, CNTs/MWCNTs, [ 5–9 ] graphene, [ 9–13 ] carbon nanofibers, [ 14,15 ] and some carbonaceous materials derived from biomass and organic precursors have been reported as porous carbon hosts for loading RP. [ 14–19 ] Among them, metal–organic frameworks (MOFs) derived porous carbons have attracted much interest due to their outstanding advantages such as controllable and high porosity, good thermal/chemical stability, high electrical conductivity, as well as easy modification with other elements and materials, etc.…”

A Porous Network of Bismuth Used as the Anode Material for High‐Energy‐Density Potassium‐Ion Batteries

“…[6] Tw o-dimensional MXene shows considerable pseudocapacitance for both Na + and K + . [6] Tw o-dimensional MXene shows considerable pseudocapacitance for both Na + and K + .…”

Advancements and Challenges in Potassium Ion Batteries: A Comprehensive Review

“…The common synthesis technique to produce the conversion type material is the conventional solid‐state technique, wherein the appropriate precursors were mixed in stoichiometric proportion and followed by annealing at high temperature. The conversion materials for K‐storage can also be prepared in various other routes, such as molten salt method, hydrothermal technique, etc . A recent study utilized a two‐step hydrothermal process to fabricate CoS@G composites ( Figure a).…”