氮掺杂淀粉基硬碳负极材料制备及其储钠性能研究

Research on the preparation and sodium storage properties of nitrogen-doped starch-based hard carbon anode material

钠离子电池(sodium-ion batteries,SIBs)作为未来极具竞争力的大型储能装置之一,由于没有合适的负极材料,其商业化应用受到严重阻碍,因此,开发新型高性能SIBs负极材料是目前亟待解决的问题之一。硬碳材料由于来源丰富和成本低廉受到广泛关注,使用马铃薯淀粉为前驱体,采用不同的氮源对马铃薯淀粉进行掺杂改性,从而制备出氮掺杂硬碳材料。测试结果表明氮掺杂硬碳材料相比于未掺杂改性材料,其电化学性能显著提高。以二氰二胺为氮源掺杂的硬碳材料在0.1 A/g的电流密度下循环100圈后,仍能保持220.47 mA·h/g的可逆比容量,以尿素为氮源的硬碳材料能保持233.36 mA·h/g可逆比容量。结果表明,氮元素的掺杂可以有效地提升硬碳材料的离子电导率、增加硬碳材料的可逆比容量,从而整体提升硬碳材料的电化学性能。

Sodium-ion batteries(SIBs)are one of the most competitive candidates for large-scale energy storage devices in the future.However,their commercial application severely lags behind due to lack of suitable anode materials,so the development of new high-performance SIBs anode materials is a pressing issue.Hard carbon materials have received much attention for their abundant sources and low cost.In this paper,nitrogen-doped hard carbon materials were prepared by doping potato starch with different nitrogen sources for modification with potato starch as a precursor.The test results showed that the electrochemical properties of the nitrogen-doped hard carbon materials were greatly improved compared with those of the undoped-modified materials.The hard carbon material doped with dicyanodiamine as the nitrogen source could still maintain a reversible specific capacity of 220.47 mA∙h/g after 100 cycles at 0.1 A/g,and the hard carbon material with urea as the nitrogen source could maintain a reversible specific capacity of 233.36 mA∙h/g after 100 cycles at 0.1 A/g.It shows that the doping of nitrogen can effectively enhance the ionic conductivity and the reversible specific capacity of hard carbon materials,thus improving the overall electrochemical performance of hard carbon materials.