Seaweed-Liked WS2/rGO Enabling Ultralong Cycling Life and Enhanced Rate Capability for Lithium-Ion Batteries

Abstract

WS2 is considered as a potential anode material for lithium ion batteries (LIBs) with superior theoretical capacity and stable structure with two-dimensional which facilitates to the transportation and storage of lithium ion. Nevertheless, the commercial recognition of WS2 has been impeded by the intrinsic properties of WS2, including poor electrical conductivity and large volume expansion. Herein, a seaweed-liked WS2/reduced graphene oxide (rGO) composites has been fabricated through a procedure involving the self-assembling of WO42−, hexadecyl trimethyl ammonium ion with graphene oxide (GO) and the subsequent thermal treatment. The WS2/rGO nanocomposite exhibited the outstanding electrochemical property with a stable and remarkable capacity (507.7 mAh·g−1) at 1.0 A·g−1 even after 1000 cycles. This advanced electrochemical property is due to its seaweed-liked feature which can bring in plentiful active sites, ameliorate the stresses arisen from volume variations and increase charge transfer rate.

The Rate Performance of Two-Dimensional Material-Based Battery Electrodes May Not Be as Good as Commonly Believed

“…The lines are fits to eq . Data are taken from the following papers: MoS 2 ; WS 2 ; graphene; and black phosphorus . All fits are shown in the SI.…”

“…The aim of this paper is to assess the rate performance of battery electrodes based on 2D materials and compare their performance to other, non-2D materials. To do this, we collected ∼48 rate performance data sets from the literature for lithium- or sodium-storing electrodes where the active material had a predominately 2D structure. ,,− ,− ,− ,− These data sets encompass 28 different 2D materials grouped in the following families: graphene; TMDs; other metal chalcogenides, oxides, or hydroxides; MXenes; and other miscellaneous materials (see Figure ). We note that not all of these materials are layered compounds where some of them ( e.g ., 2D LiFePO 4 ) were 2D platelet-shaped nanoparticles of materials with a 3D bonding scheme.…”

“…The solid-state diffusion time describes the time scale required for a Li or Na ion to diffuse within the particles of active material (AM) and is related to the diffusion length ( L AM ) and diffusion coefficient ( D AM ) via τ SSD = L AM 2 / D AM . Many authors argue that, for 2D materials, τ SSD should be short because nanosheets tend to have small L AM , − due to their tiny size, as well as relatively large D AM , − because of the expectation that ion mobility within the interlayer space would be higher than within three-dimensional (3D) particles.…”

Self‐Assembled 2D WS2 Interconnected Nanosheets: An Anode Material with Outstanding Lithium‐Storage Performance

“…The weak contact between the interlayers enables intercalation of ions between the layers. [ 6,7 ] The arrangement is favorable for Li + insertion/extraction during discharge/charge cycles between the layers and enables the subsequent storage of lithium‐based conversion reaction of the Li 2 S and W. [ 8 ] The specific capacity of WS 2 includes not only the reduction of W 4+ to W 3+ but also the diffusion of Li + into the van der Waals gaps. Having benefitted by this structural arrangement, the sandwich‐like WS 2 have a high specific capacity (432 mAh g −1 ) and have been considered as promising electrode materials for LIBs.…”

N-doped graphene encapsulated MoS2 nanosphere composite as a high-performance anode for lithium-ion batteries

“…In fact, numerous candidate anodes for LIBs have been developed and studied in recent years. Currently, transition metal sulfides with high energy density have been widely used in LIBs, such as WS 2 [4], MoS 2 [5], FeS 2 [6,7], and SnS 2 [8]. Among these candidates, layered MoS 2 has been widely concerned for its high theoretical capacity (670 mAh g −1 ) and unique two-dimensional (2D) structure [9][10][11].…”