High-Performance All-Solid-State Supercapacitor Based on the Assembly of Graphene and Manganese(II) Phosphate Nanosheets

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• 作者：Chao Yang ; Lei Dong ; Zhongxin Chen ; Hongbin Lu
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：August 21, 2014
• 年：2014
• 卷：118
• 期：33
• 页码：18884-18891
• 全文大小：476K
• ISSN：1932-7455

文摘

Manganese phosphate nanosheets (Mn₃(PO₄)₂路3H₂O NSs) with 2 nm thickness were prepared by exfoliating the bulk material in dimethylformamide (DMF) under ultrasonication. They can spontaneously form face-to-face stacked assemblies with exfoliated graphene NSs in DMF. The assemblied Mn₃(PO₄)₂路3H₂O and graphene NSs at the mass ratio of 1:10 (M₁G₁₀) revealed a specific capacitance of 2086 F g^鈥? at 1 mV s^鈥?. These M₁G₁₀ assemblies were used to fabricate all-solid-state supercapacitor (M₁G₁₀-ASSS) on the basis of PVA/KOH solid polymer electrolytes, which exhibited a specific capacitance of 152 F g^鈥? (or 40 mF cm^鈥?) at 0.5 A g^鈥?, an energy density of 0.17 渭Wh cm^鈥? at 0.5 A g^鈥? (1.3 A m^鈥?) and a power density of 46 渭W cm^鈥? at 2 A g^鈥? (5.3 A m^鈥?). M₁G₁₀-ASSS also showed excellent cycling stability and nearly 100% capacitance retention was achieved after 2000 galvanostatic charge鈥揹ischarge cycles at 2 A g^鈥?. Such extraordinary properties were attributed to the synergistic effect of high pseudocapacitance of Mn₃(PO₄)₂路3H₂O NSs, high conductivity and surface areas of graphene NSs.