Nanohybridization of CoS<sub>2</sub>/MoS<sub>2</sub> Heterostructure with Polyoxometalate on Functionalized Reduced Graphene Oxide for High‐Performance LIBs
Qian Li, Mingqi Xu, Tong Wang, Haijun Wang, Jing‐Wen Sun, Jingquan Sha
Abstract
Abstract To address the poor cycling stability and low rate capability of MoS 2 as electrode materials for lithium‐ion batteries (LIBs), herein, the CoS 2 /MoS 2 /PDDA‐rGO/PMo 12 nanocomposites are constructed via a simple hydrothermal process, combining the advantages of all three, namely, CoS 2 /MoS 2 heterojunction and polyoxometalates (POMs) provide abundant catalytically active sites and increase the multi‐electron transfer ability, and the positively charged poly(diallyldimethylammonium chloride) modified reduced graphene oxide (PDDA‐rGO) improve electronic conductivity and effectively prevent the aggregation of MoS 2 , meanwhile stabilize the negatively charged [PMo 12 O 40 ] 3− . After the electrochemical testing, the resulting CoS 2 /MoS 2 /PDDA‐rGO/PMo 12 nanocomposite achieved 1055 mA h g −1 initial specific capacities and stabilized at 740 mA h g −1 after 150 cycles at 100 mA g −1 current density. And the specific capacities of MoS 2 , MoS 2 /PDDA‐rGO, CoS 2 /MoS 2 , and CoS 2 /MoS 2 /PDDA‐rGO were 201, 421, 518, and 589 at 100 mA g −1 after 150 cycles, respectively. The fact of the greatly improving capacity of MoS 2 ‐based nanocomposites suggests its potential for high performance electrode materials of LIBs. Moreover, the lithium storage mechanism of CoS 2 /MoS 2 /PDDA‐rGO/PMo 12 has been discussed on the basis of cyclic voltammetry with different scan rates.