木质素基凝胶电极材料的组装及其电化学性能研究

Assembly of Lignin-based Hydrogel Electrode Materials and Its Electrochemical Properties

关键词:  木质素磺酸钠  石墨烯  凝胶  超级电容器

Key Words:sodium lignosulfonate  graphene  hydrogel  supercapacitor

摘要:本研究以木质素磺酸钠（LS）为功能分子，氧化石墨烯（GO）为模板，在80℃温和条件下通过一步水热法制备木质素/石墨烯复合水凝胶（LGH），并以此为自支撑的电极材料直接组装超级电容器，测试其电化学性能。通过扫描电子显微镜（SEM）、元素分析仪（EA）、傅里叶变换红外光谱仪（FT-IR）等测试和表征了LGH的微观形貌和结构组成。通过循环伏安法（CV）、恒流充放电循环法（GC）和电化学阻抗谱（EIS）测试其电化学性能。研究表明，LGH具有相互贯穿的网络结构，且木质素磺酸钠成功修饰于LGH的网络结构中。电化学测试结果表明，电流密度为1 A/g时，LGH在1 mol/L的HClO₄电解液中具有优异的质量比电容（140 F/g），为单纯石墨烯凝胶（81 F/g）的1.73倍，且该器件在电流密度20 A/g下表现出较高的倍率性能（74.3%）。

Abstract:In this study， sodium lignosulfonate （LS） and graphene oxide （GO） were used as functional molecules and templates， respectively， lignosulfonate-modified graphene hydrogel （LGH） was synthesized by one-step hydrothermal method at 80℃. And the supercapacitor was directly assembled using LGH as self-supporting electrode material to test its electrochemical performance. LGH was characterized with SEM， EA and FT-IR， and its electrochemical properties were test by cyclic voltammetry （CV）， galvanostatic charge/discharge cycling （GC）， and electrochemical impedance spectrum （EIS）. The results showed that LGH had an interpenetrating network structure and LS was successfully modified in the network structure. Besides， the electrochemical test results showed that when the current density was 1 A/g， LGH had an impressive specific capacitance of 140 F/g in 1 mol/L HClO₄ aqueous electrolyte， which was 1.73 times higher than that of pure graphene gel （81 F/g）. Moreover， the device exhibited high rate capability （74.3% capacitance retention at 20 A/g）.