椰壳活性炭孔结构对Li-S电池性能的影响

以椰壳为原料,采用化学活化法制备不同比表面积和孔结构的活性炭,通过改变制备工艺参数来调节活性炭的比表面积和孔结构。将活性炭负载60%(质量分数)硫后,作为锂硫电池的正极材料,研究活性炭孔结构对锂硫电池性能的影响。结果表明:随着活性炭比表面积的增加,中孔比例增加,锂硫电池比容量逐步提高。其中,当活化剂与炭化料的质量比为4时,活性炭的比表面积达到2900m2/g,中孔率达到15.36%。在电流密度为200mA/g时,首次放电比容量高达1294.5mAh/g,循环100次后的可逆比容量仍然高达809.3mAh/g。

Effect of Pore Structure of the Coconut Shell Activated Carbon on the Performance of Li-S Batteries

Coconut shell-based activated carbon with different surface area and pore structure was prepared through the chemical activation, which was then composited with sulfur and used as the cathode materials for lithium-sulfur batteries. Experimental results showed that the specific capacity was gradually increased with increasing the surface area and the proportion of mesoporous in activated carbon. When weight ratio between activator and carbon materials was 4, the activated carbon had a high surface area of 2900 m²/g and a proportion of mesopores of 15.36%. And the initial specific capacity of batteries was 1294.5 mAh/g at a current density of 200 mA/g and retained 809.3 mAh/g after 100 cycles which showing good cycling performance.