基于激光离焦直写炭布原位负载二氧化锰高频柔性超级电容器

柔性电子领域的快速发展,促进了人们对于储能器件的需求。超级电容器与电池相比,在充放电速率、功率密度和循环寿命等方面都具有显著优势,但当应用于高频(100 Hz以上)时,大多数超级电容器的频率响应较差,因而,开发一种能够在100 Hz以上工作的超级电容器仍然具有挑战性。本文报道了用离焦激光烧蚀法合成的MnO_(2)/炭布复合电极(LCC@MnO_(2))组成的高频柔性对称超级电容器。这种基于LCC@MnO_(2)的对称超级电容器在120 Hz下面积比电容达到1.53 mF cm^(−2),并且在100 V s^(−1)的扫速下,循环100000次仍然具有92.10%的容量保持率。其优异的电化学性能是由于三维结构炭布的高电导率和激光诱导形成的MnO_(2)纳米片优异的赝电容性能的协同作用。同时,激光烧蚀法有利于实现大规模生产,在高频电子器件产业应用中有广阔前景。

The relationship between the high-frequency performance of supercapacitors and the type of doped nitrogen in the carbon electrode

Nitrogen doping has been widely used to improve the performance of carbon electrodes in supercapacitors,particularly in terms of their high-frequency response.However,the charge storage and electrolyte ion response mechanisms of different nitrogen dopants at high frequencies are still unclear.In this study,melamine foam carbons with different configurations of surfacedoped N were formed by gradient carbonization,and the effects of the configurations on the high-frequency response behavior of the supercapacitors were analyzed.Using a combination of experiments and first-principle calculations,we found that pyrrolic N,characterized by a higher adsorption energy,increases the charge storage capacity of the electrode at high frequencies.On the other hand,graphitic N,with a lower adsorption energy,increases the speed of ion response.We propose the use of adsorption energy as a practical descriptor for electrode/electrolyte design in high-frequency applications,offering a more universal approach for improving the performance of N-doped carbon materials in supercapacitors.