Liu Shude, Yin Ying, Shen Yang, Hui Kwan San, Chun Young Tea, Kim Jong Min, Hui Kwun Nam, Zhang Lipeng, Jun Seong Chan
School of Mechanical Engineering, Yonsei University, Seoul, 120749, South Korea.
Guangxi Key Laboratory of Information Materials, Guilin University of Electronic Technology, Guilin, 541000, P. R. China.
Small. 2020 Jan;16(4):e1906458. doi: 10.1002/smll.201906458. Epub 2020 Jan 1.
Battery-type materials are promising candidates for achieving high specific capacity for supercapacitors. However, their slow reaction kinetics hinders the improvement in electrochemical performance. Herein, a hybrid structure of P-doped Co O (P-Co O ) ultrafine nanoparticles in situ encapsulated into P, N co-doped carbon (P, N-C) nanowires by a pyrolysis-oxidation-phosphorization of 1D metal-organic frameworks derived from Co-layered double hydroxide as self-template and reactant is reported. This hybrid structure prevents active material agglomeration and maintains a 1D oriented arrangement, which exhibits a large accessible surface area and hierarchically porous feature, enabling sufficient permeation and transfer of electrolyte ions. Theoretical calculations demonstrate that the P dopants in P-Co O @P, N-C could reduce the adsorption energy of OH and regulate the electrical properties. Accordingly, the P-Co O @P, N-C delivers a high specific capacity of 669 mC cm at 1 mA cm and an ultralong cycle life with only 4.8% loss over 5000 cycles at 30 mA cm . During the fabrication of P-Co O @P, N-C, Co@P, N-C is simultaneously developed, which can be integrated with P-Co O @P, N-C for the assembly of asymmetric supercapacitors. These devices achieve a high energy density of 47.6 W h kg at 750 W kg and impressive flexibility, exhibiting a great potential in practical applications.
电池型材料是实现超级电容器高比容量的有前途的候选材料。然而，它们缓慢的反应动力学阻碍了电化学性能的提高。在此，报道了一种通过对源自钴层状双氢氧化物的一维金属有机框架进行热解-氧化-磷化反应，将P掺杂的CoO（P-CoO）超细纳米颗粒原位封装到P、N共掺杂碳（P、N-C）纳米线中的杂化结构，该一维金属有机框架作为自模板和反应物。这种杂化结构可防止活性材料团聚并保持一维取向排列，呈现出大的可及表面积和分级多孔特征，使电解质离子能够充分渗透和转移。理论计算表明，P-CoO@P、N-C中的P掺杂剂可降低OH的吸附能并调节电学性质。因此，P-CoO@P、N-C在1 mA cm下具有669 mC cm的高比容量，在30 mA cm下经过5000次循环仅有4.8%的损失，具有超长的循环寿命。在制备P-CoO@P、N-C的过程中，同时开发了Co@P、N-C，其可与P-CoO@P、N-C集成用于组装不对称超级电容器。这些器件在750 W kg下实现了47.6 W h kg的高能量密度和令人印象深刻的柔韧性，在实际应用中展现出巨大潜力。
