Pyrene‐Anderson‐Modified CNTs as Anode Materials for Lithium‐Ion Batteries

Abstract

An organo-functionalized polyoxometalate (POM)-pyrene hybrid (Py-Anderson) has been used for noncovalent functionalization of carbon nanotubes (CNTs) to give a Py-Anderson-CNT nanocomposite through π-π interactions. The as-synthesized nanocomposite was used as the anode material for lithium-ion batteries, and shows higher discharge capacities and better rate capacity and cycling stability than the individual components. When the current density was 0.5 mA cm(-2), the nanocomposite exhibited an initial discharge capacity of 1898.5 mA h g(-1) and a high discharge capacity of 665.3 mA h g(-1) for up to 100 cycles. AC impedance spectroscopy provides insight into the electrochemical properties and the charge-transfer mechanism of the Py-Anderson-CNTs electrode.

Dawson‐Type Polyoxomolybdate Anions (P2Mo18O626−) Captured by Ionic Liquid on Graphene Oxide as High‐Capacity Anode Material for Lithium‐Ion Batteries

“…As shown in Figure b, a first discharge capacity of 1433 mAh g −1 was obtained for the GO‐IL‐P 2 Mo 18 electrode under the experimental conditions. The capacity of the electrode decreased rapidly to 945 mAh g −1 in the second cycle owing to the formation of an SEI film . For the GO‐IL (Figure a), the first and second discharge capacities are 425 and 256 mAh g −1 , respectively, which are much lower than those of the nanocomposite.…”

“…The capacity of the electrode decreased rapidly to 945 mAh g À1 in the second cycleo wing to the formation of an SEI film. [21] For the GO-IL (Figure 5a), the first and second discharge capacities are 425 and 256 mAh g À1 ,r espectively,w hich are much lower than those of the nanocomposite.…”

“…combined TBA 3 PMo 12 O 40 with SWNTs as a cathode material for LIBs, which exhibits a capacity of around 250 mA g −1 in the voltage range 1.5–4.2 V. This result opens the possibilities of POM‐based electrode materials . Our group first studied a nanocomposite of pyrene‐modified POMs and SWNTs, and its application as an LIB anode material showed improved charge‐transfer efficiency . Later, we reported the preparation of Anderson covalently functionalized SWNTs, and electrochemical analyses indicated that the resultant nanocomposite had a high discharge capacity of up to 932 mAh g −1 at a current density of 0.5 mA cm −2 with excellent stability .…”

“…[17,19] Our group first studied an anocomposite of pyrene-modified POMs and SWNTs, and its applicationa sa n LIB anode material showed improved charge-transfer efficiency. [20,21] Later,w er eportedt he preparation of Anderson covalently functionalized SWNTs, and electrochemical analyses indicated that the resultant nanocomposite had ah igh discharge capacityo fu pto 932 mAh g À1 at ac urrent density of 0.5 mA cm À2 with excellent stability. [22] Li et al reported the amino-graphene/Al-Andersonn anocomposite as an anode material with an enhanced capacity of approximately 1000 mAh g À1 and al ong cycle life of over 1000 cycles.…”

Polyoxometalate‐Based Bottom‐Up Fabrication of Graphene Quantum Dot/Manganese Vanadate Composites as Lithium Ion Battery Anodes

“…Notably, the formation of the nanocomposite during synthesis can be observed by emission spectroscopy; after sonication of {MnV 12 } acetonitrile solution and the strongly emitting GQDs dispersion, a significant loss of emission intensity is observed (Figure i), indicating the formation of interactions between both species . FT‐IR spectroscopy of composite 1 shows the characteristic GQD vibrational modes (mainly C−C, C−N, C−O, C−H) as well as metal oxide modes (mainly M−O and M−O−M (M=V, Mn)) (see Figure h and the Supporting Information for detailed assignments) …”