Abstract:

Using cheap cation exchange resin as the carbon source, iron ions are introduced based on the ion exchange strategy to regulate the graphitized carbon structure during the pyrolysis process of the cation exchange resin. And further acid etched the elemental iron and iron carbide in the pyrolysis product to prepare a mesoporous graphitized carbon for use as anode material for sodium-ion batteries. The cation exchange resin based graphitic carbon shows larger intergraphene spacing, lower defects and mesoporous tunnels constructed by few graphite layers compared with the hard carbon by direct pyrolysis of resin, which could significantly improve the capacity and cycling stability and carbon anode material at high rates. When applied to anode material in sodium ion battery, this material exhibits excellent rate performance and cycling stability at high rates, showing a specific capacity of 100 mA·h·g^-1 at a high current density of 30 A·g^-1, and a specific capacity of 192 mA·h·g^-1 at a current density of 0.5 A·g^-1 after 1000 cycles.

Key words: nanostructure, pyrolysis, electrochemistry, sodium ion battery, graphitic carbon

摘要：

利用价格低廉的阳离子交换树脂作为碳源，基于离子交换策略引入铁离子，调控阳离子交换树脂热解过程的石墨化碳结构，并进一步酸刻蚀热解产物中的单质铁和碳化铁，制备了一种介孔石墨化碳，用于钠离子电池负极材料。阳离子交换树脂基介孔石墨化碳相比直接热解所得的树脂基硬碳具有更大的层间距、更少的缺陷结构以及由薄层石墨化碳构成的介孔孔道，可以显著提高碳负极材料在高倍率下的比容量及循环稳定性。将该材料应用于钠离子电池负极材料展示出优异的倍率性能和高倍率下的循环稳定性，在30 A·g^-1的高电流密度下该材料的比容量可达100 mA·h·g^-1，在0.5 A·g^-1的电流密度下循环1000圈后比容量可保持在192 mA·h·g^-1。

关键词: 纳米结构, 热解, 电化学, 钠离子电池, 石墨化碳