Heterogeneous and microporous structure evolution of heated/radiated polyacrylonitrile fibers revealed by micro X-ray computed tomography and scattering

Nanoscale, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Heat treatment, a critical pre-oxidation process, plays an essential role in the preparation of carbon fibers. Most defects arising from this stage are likely to be transferred final Electron beam irradiation is effective modification method optimize structure polyacrylonitrile (PAN) pre-oxidized In order investigate microstructural evolution irradiated PAN fibers during heat treatment synchrotron radiation X-ray micro-computed tomography (micro-CT) was used work and 3D four layer obtained. The process also characterized by situ small-angle scattering (SAXS) wide-angle (WAXS). results indicate that electron enhances cross-linking cyclization while reducing initial temperature. micro-CT show makes ratio each change process. proportion both outer inner skin increased significantly, sub-skin decreased. Additionally, there slight decline core-skin proportion. A gradual transition loose dense state occurs between layers, reduces heterogeneity among them. Further experiments showed microporous size decreased relative untreated Irradiation enables oxygen diffuse deeper into fiber, oxidation reactions, facilitates PAN.

Language: Английский

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Polar‐Nonpolar Synergy Toward High‐Performance Aqueous Zinc–Iodine Batteries

Small, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 21, 2025

Abstract Aqueous zinc‐iodine batteries (AZIBs) hold great promise for large‐scale energy storage due to their inherent safety, cost‐effectiveness, and environmental sustainability. However, practical application is hindered by the sluggish redox kinetics of iodine species “shuttle effect” polyiodides, both which degrade cycling stability capacity retention. Herein, a “polar‐nonpolar strategy” proposed first time, couples nonpolar porous carbon (PC) as host with highly polar zinc oxide (ZnO) separator modification materials. Specifically, PC leverages its structure properties accommodate immobilize iodine, simultaneously enhancing conductivity cathode. Meanwhile, ZnO on accelerates electron transfer polyiodides through strong adsorption catalytic effects, improving reversible transformation species. UV–visible spectroscopy electrochemical kinetic analyses confirm rapid effective polyiodide inhibition in this system. As result, prepared PC‐I 2 //ZnO@GF battery demonstrates high‐rate excellent long‐term stability, surpassing performance other recently reported AZIBs. This polar‐nonpolar strategy establishes novel design rationale developing future high‐performance batteries.

Language: Английский

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High‐Strength MOF‐Based Polymer Electrolytes with Uniform Ionic Flow for Lithium Dendrite Suppression

Small, Journal Year: 2024, Volume and Issue: 20(46)

Published: Aug. 10, 2024

Abstract The uneven formation of lithium dendrites during electroplating/stripping leads to a decrease in the utilization active lithium, resulting poor cycling stability and posing safety hazards battery. Herein, introducing 3D continuously interconnected zirconium‐based metal‐organic framework (MOF808) network into polyethylene oxide polymer matrix establishes synergistic mechanism for dendrite inhibition. MOF808 maintains its large pore structure, facilitating increased salt accommodation, expands anion adsorption at unsaturated metal sites through diverse large‐space cage thereby promoting flow Li + . Infrared‐Raman synchrotron small‐angle X‐ray scattering results demonstrate that transport behavior ion clusters MOF/polymer interface verifies local flux concentration, raising mobility number 0.42 ensuring uniform distribution, leading dendrite‐free homogeneous deposition. Furthermore, nanoindentation tests reveal high modulus elastic recovery MOF‐based electrolytes contribute forming robust, dendrite‐resistant interface. Consequently, symmetric battery systems, system exhibits minimal overpotential, merely 35 mV, while maintaining stable over 1800 h, achieving low–overpotential Moreover, it retains redox under voltages up 5.3 V.

Language: Английский

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Triazine Ring and Sulfhydryl-Enabled Binder Design: A Path to Superior Zinc Ion Batteries with Enhanced Ion Transport

ACS Applied Energy Materials, Journal Year: 2025, Volume and Issue: unknown

Published: May 20, 2025

Language: Английский

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An oxygen-defective framework with intensified Lewis acidity reinforcing composite electrolyte for all-solid-state lithium metal batteries

Energy storage materials, Journal Year: 2024, Volume and Issue: 73, P. 103847 - 103847

Published: Oct. 18, 2024

Language: Английский

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