氮氧掺杂木质素基炭材料的制备及其电化学性能

Synthesis of Nitrogen and Oxygen-doped Ligin-based Electrode Materials and Its Electrochemical Performance

以工业废弃物木质素磺酸钠为碳源,高含氮量的三聚氰胺为氮源,通过共混物直接热解制得高氮氧含量的木质素基炭材料(NSL-x),当三聚氰胺与木质素磺酸钠的质量比值为2、4和6时,分别标记为NSL-2、NSL-4和NSL-6;采用SEM、XRD和XPS等方法对其形貌和结构进行了表征。结果表明:NSL-x整体是由尺寸为几百纳米到几微米的无规则炭块堆积而成;氮氧掺杂并没有改变其形貌和结晶结构,炭化产物以无定形碳为主。炭材料NSL-4含氮量可达2.41%,含氧量达到20.12%,同时NSL-4中所含的羰基最高(10.27%)。样品的电化学性能测试结果表明:以6 mol/L KOH为电解液,在0.1 A/g的电流密度下,NSL-4的比电容达到229 F/g,在20 A/g的高电流密度下,比电容仍维持在137 F/g。在10 A/g的电流密度下,经过10 000次的充放电循环测试,NSL-4的库伦效率仍然保持在100%左右,比电容仅下降了1%,表现出良好的倍率性能和极佳的电化学稳定性。

Nitrogen and oxygen-doped carbon materials（ NSL-x） were prepared by one-pot pyrolysis of sodium lignin sulfonate as carbon precursor and melamine as nitrogen precursor. The morphology and structure of obtained materials were characterized by SEM,XRD,XPS analysis. The results showed that NSL-x was composed of irregular carbon block with size ranging from hundreds of nanometers to several microns. Nitrogen doping did not change the morphology and crystalline structure of carbon block,the amorphous carbon structure was the main form of NSL-x. When the mass ratio of melamine and sodium lignin sulfonate was 4,nitrogen and oxygen content of the obtained NSL-4 can reached 2. 41% and 20. 12%,respectively. Electrochemical performance test results showed that NSL-4 exhibited a high capacitance of 229 F/g at the current density of 0.1 A/g in 6 mol/L KOH electrolyte,and even remained 137 F/g at 20 A/g. Meanwhile,under the current density of 10 A/g,NSL-4 remained 100% coulomb efficiency with only 1% capacity loss after 10 000 consecutive charge/discharge cycles,and showed excellent electrochemical stability.