Peixun Xiong

Bio: Peixun Xiong is an academic researcher from Sungkyunkwan University. The author has contributed to research in topics: Hydroxide & Quantum dot. The author has an hindex of 3, co-authored 5 publications receiving 18 citations.

Unveiling Trifunctional Active Sites of a Heteronanosheet Electrocatalyst for Integrated Cascade Battery/Electrolyzer Systems

Abstract: Herein, we identify the unique trifunctional active sites of ReS2 and NiFe layered double hydroxide (NiFe-LDH) heteronanosheets (ReS2/NiFe-LDH) for integrated cascade Zn–air battery/electrolyzer systems. Along with the edge and surface sites of NiFe-LDH for both oxygen evolution reaction and oxygen reduction reaction activities, the unprecedented activity of the ReS2/NiFe-LDH heteronanosheets for the hydrogen evolution reaction emerges from the S–O bonds at the heterointerfaces, together with the strong coupling effect and vertical alignment of NiFe-LDH and ReS2. The outstanding trifunctional activities and a well understood mechanism ensure the use of ReS2/NiFe-LDH heteronanosheets for the development of integrated cascade battery/electrolyzer systems, in which electricity storage in the battery mode and H2 production in the electrolyzer mode are efficiently switched with high round-trip efficiency (61%) and Faraday efficiency (96%). The systems show great promise for cost-effective energy storage and H2 production applications ranging from the distribution in households to the assembly for electrical vehicles.

Two-Dimensional Pseudocapacitive Nanomaterials for High-Energy- and High-Power-Oriented Applications of Supercapacitors

Abstract: ConspectusSupercapacitors (SCs) are electrochemical energy storage devices that can fill the gap between batteries and electrolytic capacitors. However, the widespread applications of commercialize...

Layered Double Hydroxide Quantum Dots for Use in a Bifunctional Separator of Lithium–Sulfur Batteries

Abstract: Functional separators, which are chemically modified and coated with nanostructured materials, are considered an effective and economical approach to suppressing the shuttle effect of lithium polysulfide (LiPS) and promoting the conversion kinetics of sulfur cathodes. Herein, we report cobalt-aluminum-layered double hydroxide quantum dots (LDH-QDs) deposited with nitrogen-doped graphene (NG) as a bifunctional separator for lithium-sulfur batteries (LSBs). The mesoporous LDH-QDs/NG hybrids possess abundant active sites of Co2+ and hydroxide groups, which result in capturing LiPSs through strong chemical interactions and accelerating the redox kinetics of the conversion reaction, as confirmed through X-ray photoelectron spectroscopy, adsorption tests, Li2S nucleation tests, and electrokinetic analyses of the LiPS conversion. The resulting LDH-QDs/NG hybrid-coated polypropylene (LDH-QDs/NG/PP) separator, with an average thickness of ∼17 μm, has a high ionic conductivity of 2.67 mS cm-1. Consequently, the LSB cells with the LDH-QDs/NG/PP separator can deliver a high discharge capacity of 1227.48 mAh g-1 at 0.1C along with a low capacity decay rate of 0.041% per cycle over 1200 cycles at 1.0C.

Interfacial Engineering Strategy for High-Performance Zn Metal Anodes.

Abstract: Due to their high safety and low cost, rechargeable aqueous Zn-ion batteries (RAZIBs) have been receiving increased attention and are expected to be the next generation of energy storage systems. However, metal Zn anodes exhibit a limited-service life and inferior reversibility owing to the issues of Zn dendrites and side reactions, which severely hinder the further development of RAZIBs. Researchers have attempted to design high-performance Zn anodes by interfacial engineering, including surface modification and the addition of electrolyte additives, to stabilize Zn anodes. The purpose is to achieve uniform Zn nucleation and flat Zn deposition by regulating the deposition behavior of Zn ions, which effectively improves the cycling stability of the Zn anode. This review comprehensively summarizes the reaction mechanisms of interfacial modification for inhibiting the growth of Zn dendrites and the occurrence of side reactions. In addition, the research progress of interfacial engineering strategies for RAZIBs is summarized and classified. Finally, prospects and suggestions are provided for the design of highly reversible Zn anodes. Highlights: 1 The interfacial engineering strategies of surface and electrolyte modifications for high-performance Zn metal anodes are reviewed.2 The reaction mechanisms for inhibiting dendrite growth and side reactions in interface engineering are systematically summarized.3 An outlook on future reference directions for new interface strategies to advance this field is provided.

MXene Nanoarchitectonics: Defect‐Engineered 2D MXenes towards Enhanced Electrochemical Water Splitting

Abstract: 2D MXenes‐based nanoarchitectures are being actively explored for electrocatalytic water splitting because they possess physical and physiochemical properties that enhance catalytic activity toward the hydrogen evolution reaction and oxygen evolution reaction. This review systematically summarizes current strategies involved in defect engineering, including introducing atomic vacancies and active edges, and doping with metal and non‐metal atoms, which have been employed to achieve high‐efficiency MXenes‐based catalysts. The electronic structures, optimized adsorption/desorption energies of the intermediates, and possible catalytic mechanisms resulting from various defects are disclosed based on combined experimental results and theoretical calculations. Current challenges and future opportunities for the mechanistic investigation and practical application of defective MXenes‐based catalysts are proposed. This report aims to reveal the nature of defective MXenes electrocatalysts and to provide valuable guidelines for designing defective MXenes‐based nanoarchitectures for various catalytic reactions.