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Indexed by:期刊论文

Date of Publication:2016-08-10

Journal:ELECTROCHIMICA ACTA

Included Journals:SCIE、EI、Scopus

Volume:209

Page Number:350-359

ISSN No.:0013-4686

Key Words:Sn@SnO2 attached on carbon spheres; In-situ formation; Conductive reagent-free electrode; Electrochemical stability; Pseudocapacitor

Abstract:Utilization of metal oxide/supports interface structures could generate high-performance electrochemical materials for clean energy storage and conversion. However, designing the metal oxide/supports interfaces with highly enhanced conductivity and cycle durability remains a significant challenge. Here, we demonstrate an in-situ growth technique to synthesize a Sn/SnO2@C composite with nano-Sn species attached on surface of carbon spheres (denoted as Sn/SnO2@C) during the carbonization of a sol-gel precursors of tin (IV) tetrachloride pentahydrate (SnCl4 center dot 5H(2)O) and Resorcinol-Formaldehyde (Sn4+-RF) in N-2. We investigate the nucleation and crystal growth of Sn/SnO2 from Sn4+-RF precursor to Sn/SnO2@C composite with the variation of the concentration of acid value and heat-treatment temperature. Sn/SnO2@C-(1.0, 800) composite as supercapacitor electrode achieves a maximum specific capacitance of 906.8 F g(-1) at a scan rate of 1 mV s(-1) in 6 M KOH solution, and an excellent cycle durability of 2000 cycles at 5 A g(-1). The electrochemical performances demonstrate that charge storage occurs in Sn/SnO2@C mainly due to redox reactions between the binary oxidation states: Sn <-> Sn(OH)(6)(2-)(IV) in basic electrolyte, hierarchical porosity and Sn/SnO2@C distinct structure, which is formed in situ. The work provides new insights into the rational design of Sn@C composites electrode materials for pseudocapacitor and other electrochemical devices. (C) 2016 Elsevier Ltd. All rights reserved.