Ramírez Cristina, Osendi María Isabel, Moyano Juan José, Mosa Jadra, Aparicio Mario
Institute of Ceramics and Glass (ICV), Consejo Superior de Investigaciones Científicas, CSIC, Kelsen 5, Cantoblanco, 28049 Madrid, Spain.
Universidad Politécnica de Madrid, 28040 Madrid, Spain.
Materials (Basel). 2023 Jul 31;16(15):5386. doi: 10.3390/ma16155386.
Graphene and its derivatives have been widely used to develop novel materials with applications in energy storage. Among them, reduced graphene oxide has shown great potential for more efficient storage of Na ions and is a current target in the design of electrodes for environmentally friendly Na ion batteries. The search for more sustainable and versatile manufacturing processes also motivates research into additive manufacturing electrodes. Here, the electrochemical responses of porous 3D-printed free-standing log-type structures fabricated using direct ink writing (DIW) with a graphene oxide (GO) gel ink are investigated after thermal reduction in a three-electrode cell configuration. The structures delivered capacities in the range of 50-80 mAh g and showed high stability for more than 100 cycles. The reaction with the electrolyte/solvent system, which caused an initial capacity drop, was evidenced by the nucleation of various Na carbonates and NaO. The incorporation of Na into the filaments of the structure was verified with transmission electron microscopy and Raman spectroscopy. This work is a proof of concept that structured reduced GO electrodes for Na ion batteries can be achieved from a simple, aqueous GO ink through DIW and that there is scope for improving their performance and capacity.
石墨烯及其衍生物已被广泛用于开发具有能量存储应用的新型材料。其中，还原氧化石墨烯在更高效地存储钠离子方面显示出巨大潜力，并且是环保型钠离子电池电极设计的当前目标。对更可持续和通用的制造工艺的探索也推动了对增材制造电极的研究。在此，研究了使用氧化石墨烯（GO）凝胶墨水通过直接墨水书写（DIW）制造的多孔3D打印自立式原木型结构在三电极电池配置中热还原后的电化学响应。这些结构的容量在50-80 mAh g范围内，并在100多个循环中表现出高稳定性。各种碳酸钠和NaO的成核证明了与电解质/溶剂系统的反应导致了初始容量下降。通过透射电子显微镜和拉曼光谱验证了钠掺入结构的细丝中。这项工作证明了通过DIW从简单的水性GO墨水可以实现用于钠离子电池的结构化还原GO电极，并且有改进其性能和容量的空间。
