富氮掺杂碳空心纳米笼协同钴镍硫化物提升超级电容器性能

采用简单的热解-硫化两步法成功制备了一种新型的富氮掺杂碳空心纳米笼(NC)负载双元金属硫化物纳米颗粒(CoNi_xS_y)的复合材料 CoNi_xS_y/NC。该策略以丁二酮肟镍为镍源,增加了活性位点,同时前驱体 ZIF-8@Ni-ZIF-67的核壳结构为空心碳纳米笼的构建提供了可能性。这种独特的负载多金属硫化物纳米颗粒的中空结构使CoNi_xS_y/NC作为电极材料时具有更多的活性位点、更高的导电性和结构稳定性,从而使其具有较高的比容量(1 A·g^-1时比容量为629.2 F·g^-1),优异的循环稳定性(1 A·g^-1下1 000次循环测试后容量保持率为93.4%)。当将其进一步组装成对称超级电容器后,在1 A·g^-1下可提供207.2 F·g^-1的比电容,1 000圈循环稳定后的容量保持率为85.36%。

Nitrogen-rich doped carbon hollow nanocage structure cooperating with cobalt-nickel sulfide to improve the performance of supercapacitors

A novel nitrogen-rich doped carbon hollow nanocage (NC) supported binary metal sulfide nanoparticle (CoNi_xS_y) composite CoNi_xS_y/NC was successfully prepared by a simple pyrolysis-vulcanization two-step method. In this strategy, dimethylglyoxime nickel was used as the nickel source to increase the active site, and the core-shell structure of the precursor ZIF-8@Ni-ZIF-67 provided the possibility for the construction of hollow carbon nanocages. More importantly, this unique hollow structure loaded with binary metal sulfide nanoparticles made the CoNi_xS_y/NC possess more active sites, high conductivity, and structural stability when used as an electrode material, thereby providing a higher specific capacity (629.2 F·g^-1 at 1 A·g^-1) and excellent cycle stability (93.4% capacity retention after 1 000 cycles at 1 A·g^-1). When further assembled into a symmetrical supercapacitor, a specific capacitance of 207.2 F·g^-1 can be provided at 1 A·g^-1, and the retention rate was 85.36% after 1 000 cycles of stabilization.