采用水热法制备ZnO/石墨烯复合材料,研究了ZnO、石墨烯不同配比与其电化学性能的关系。通过X射线衍射(XRD)、扫描电镜(SEM)、恒电流充放电、循环伏安法和交流阻抗等测试方法对复合材料结构、形貌及电化学性能进行表征,并通过电池解扣结合SEM和EDS进一步研究电极充放电前后的形貌及组分变化。结果表明,Zn O与石墨烯质量比为1∶1时电化学性能最好,在50 m A/g电流密度下首次可逆比容量高达680 m Ah/g,且循环100次之后仍保持相对最高。电池解扣分析证明电极材料在充放电过程中表面会产生微裂纹影响其电化学性能。
High performance supercapacitors were constructed using ionic liquid 1-ethyl-3-methylimidazolium thi- ocyanate（EmimSCN）-based electrolyte with chemically reduced graphene oxide（CRGO） as electrodes. Propylene carbonate（PC） was selected as the solvent due to its stable physical and electrochemical properties. Then, in-depth study of the concentration and temperature effects on the electrochemical properties of the EmimSCN/PC electrolyte was carried out. Electrochemical measurements revealed that 2.0 mol/L EmimSCN/PC electrolyte delivered good electrochemical performance（131 F/g of the specific capacity after 3000 cycles at room temperature）. Moreover, the assembled supercapacitors exhibited good capacitive behavior at an extending temperature（397 F/g of the specific capacity after 3000 cycles at 50 ℃）, demonstrating that the EmimSCN/PC electrolyte is a promising candidate for safe high-power supercapacitors.
