Confined grotthuss proton-conduction along polyoxometalate chains inside carbon nanotubes for high-rate charge storage

Zhu，Sheng1,3; Yang，Xiaoxin2; Li，Lan1; Wang，Xiao2,4; Han，Gaoyi1,3

2024-05-15

10.1016/j.cej.2024.150744

Chemical Engineering Journal   影响因子和分区

1385-8947

Redox-active materials with excellent rate capability and cycling performance are in highly demand for electrochemical energy storage and conversion applications. Here, we unveil the confined proton-conduction behavior of one-dimensional polyoxometalate chains inside single-walled carbon nanotubes (SWNTs). The polyoxometalate molecules including phosphomolybdic acid {HPMo} and phosphotungstic acid {HPW} are encapsulated within SWNTs via host–guest recognition, driven by the electron transfer from nanotubes to polyoxometalates. Impressively, the redox hybrids of polyoxometalate@SWNTs deliver abnormal rate performance in acidic solution with capacity retentions over 73 % at high sweep rate of 1000 mV s, relative to the capacity at 10 mV s. This value is comparable to that of the pure SWNTs, typically known as double-layer capacitive materials. Electrochemical analyses reveal the Grotthuss proton-conduction mechanism of {HPMo} in SWNTs with a low activation energy of 0.11 eV. Therefore, the {HPMo}@SWNT hybrid demonstrates quasi diffusion-free characteristic with dominant capacitive contribution over 60 % at different sweep rates. Molecular dynamic simulations and density functional theory calculations evidence the strong burst-like transport of protons in the {HPMo}@SWNT hybrid. This process is dynamically favored in the continuous and long-range hydrogen-bond network along polyoxometalate chains with bound/free water molecules inside SWNTs. The superiority of nanoconfined Grotthuss mechanism may engender an exciting avenue for developing high-performance energy storage materials.

Carbon nanotubes Charge storage Heterostructure Polyoxometalates Proton-conduction

SCI ; EI

英语

其他

ENGINEERING

2-s2.0-85189561685

Scopus

1.Institute of Molecular Science,Key Lab of Materials for Energy Conversion and Storage of Shanxi Province,Key Laboratory of Chemical Biology and Molecular Engineering of Education Ministry,Shanxi University,Taiyuan,030006,China
2.Institute of Technology for Carbon Neutrality,Shenzhen Institute of Advanced Technology,Chinese Academy of Sciences,Shenzhen,518055,China
3.Institute for Carbon-Based Thin Film Electronics,Peking University,Shanxi (ICTFE-PKU),Taiyuan,030012,China
4.Guangdong Provisional Key Laboratory of Functional Oxide Materials and Devices,Southern University of Science and Technology,Shenzhen,518055,China

Zhu，Sheng,Yang，Xiaoxin,Li，Lan,et al. Confined grotthuss proton-conduction along polyoxometalate chains inside carbon nanotubes for high-rate charge storage[J]. Chemical Engineering Journal,2024,488.

Zhu，Sheng,Yang，Xiaoxin,Li，Lan,Wang，Xiao,&Han，Gaoyi.(2024).Confined grotthuss proton-conduction along polyoxometalate chains inside carbon nanotubes for high-rate charge storage.Chemical Engineering Journal,488.

Zhu，Sheng,et al."Confined grotthuss proton-conduction along polyoxometalate chains inside carbon nanotubes for high-rate charge storage".Chemical Engineering Journal 488(2024).