High-performance hybrid supercapacitor based on pure and doped Li₄Ti₅O₁₂ and graphene

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• 作者：M. Khairy ; K. Faisal ; M.A. Mousa
• 关键词：Nanoparticles ; Hybrid supercapacitor ; Li4Ti5O12 ; Graphene ; Cyclic voltammetry
• 刊名：Journal of Solid State Electrochemistry
• 出版年：2017
• 出版时间：March 2017
• 年：2017
• 卷：21
• 期：3
• 页码：873-882
• 全文大小：n>
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Physical Chemistry; Electrochemistry; Energy Storage; Characterization and Evaluation of Materials; Analytical Chemistry; Condensed Matter Physics;
• 出版者：Springer Berlin Heidelberg
• ISSN：1433-0768
• 卷排序：21

文摘

Graphene nanosheets (G) and pure, as well as doped Mg-, Mn-, V-Li₄Ti₅O₁₂, spinel structure have been synthesized. As-prepared materials were characterized by X-ray powder diffraction (XRD), FT-IR, scanning electron microscopy (SEM), cyclic voltammetry, and constant current discharge methods. The physical properties, as well as the possible role of the doped materials in supercapacitors, have been studied. The hybrid supercapacitor with pure or doped Li₄Ti₅O₁₂ (LTO) anode was fabricated afterward to form the graphene/Li₄Ti₅O₁₂. The specific energy, specific power, fast-charge capability, lifecycle, and self-discharge of the studied devices were compared. Metal doping did not change the phase structure while remarkably improved its capacitance at high charge/discharge rate. The hybrid supercapacitor utilizing pure or doped Li₄Ti₅O₁₂ as an anode exhibits high capacitance compared to DLC because of the electrochemical process with intercalation/deintercalation of lithium into the spinel LTO. The capacitance of the hybrid supercapacitor decreases from 207 to 108 Fg−1 when discharged at several specific current densities ranging from 1 to 10 Ag−1. In contrast, the capacitance of the DLC is slightly decreased.