Pan Dong-Sheng, Guo Zheng-Han, Li Jin-Kun, Huang Sai, Zhou Ling-Li, Song Jun-Ling
International Joint Research Center for Photoresponsive Molecules and Materials, School of Chemical and Material Engineering, Jiangnan University, Lihu Street 1800, Wuxi, 214122, P. R. China.
Chemistry. 2021 May 17;27(28):7731-7737. doi: 10.1002/chem.202100383. Epub 2021 May 11.
Transition-metal phosphates have been widely applied as promising candidates for electrochemical energy storage and conversion. In this study, we report a simple method to prepare a N, F co-doped mesoporous cobalt phosphate with rich-oxygen vacancies by in-situ pyrolysis of a Co-phosphate precursor with NH cations and F anions. Due to this heteroatom doping, it could achieve a current density of 10 mA/cm at lower overpotential of 276 mV and smaller Tafel slope of 57.11 mV dec on glassy carbon. Moreover, it could keep 92 % of initial current density for 35 h, indicating it has an excellent stability and durability. Furthermore, the optimal material applied in supercapacitor displays specific capacitance of 206.3 F g at 1 A ⋅ g and maintains cycling stability with 80 % after 3000 cycles. The excellent electrochemical properties should be attributed to N, F co-doping into this Co-based phosphate, which effectively modulates its electronic structure. In addition, its amorphous structure provides more active sites; moreover, its mesoporous structure should be beneficial to mass transfer and electrolyte diffusion.
过渡金属磷酸盐作为电化学储能和转换领域颇具潜力的候选材料已被广泛应用。在本研究中，我们报道了一种简单的方法，即通过对含有NH阳离子和F阴离子的磷酸钴前驱体进行原位热解，制备出具有丰富氧空位的N、F共掺杂介孔磷酸钴。由于这种杂原子掺杂，它在玻碳电极上能够在276 mV的较低过电位和57.11 mV dec的较小塔菲尔斜率下实现10 mA/cm的电流密度。此外，它能够在35 h内保持92%的初始电流密度，表明其具有优异的稳定性和耐久性。此外，应用于超级电容器的最佳材料在1 A ⋅ g时显示出206.3 F g的比电容，并在3000次循环后保持80%的循环稳定性。优异的电化学性能应归因于N、F共掺杂到这种钴基磷酸盐中，这有效地调节了其电子结构。此外，其非晶结构提供了更多的活性位点；而且，其介孔结构有利于传质和电解质扩散。
