Department of Chemical and Biological Engineering, Jeju National University, Jeju-63243, Republic of Korea.
Nanomaterials and System Laboratory, Department of Mechatronics Engineering, Jeju National University, Jeju 63243, Republic of Korea.
Dalton Trans. 2020 Oct 27;49(41):14506-14519. doi: 10.1039/d0dt02204g.
An essential key to enhancing the specific capacity and cyclic stability of transition metal oxide materials is the hybridization of carbon compounds by binder-free methods for supercapacitors. Carbonaceous compounds shorten the electron-ion diffusion pathways due to their high active surface area and conductivity. Herein, we focus on improving the specific energy, stability, and conductivity of the electrode by the incorporation of nanosized carbon material. The integration of nano carbons from viable eco-friendly glucose with CoMoO4 enhanced the experimental specific capacity of the electrode. The self-grown CoMoO4 on a nickel foam (CMO-NF) was confirmed as the best approach after extensive optimization process by the feasible hydrothermal (HT) method. The amount of carbon deposited and the structural morphology on the fabricated CoMoO4-glucose-derived carbon (CMO-GC) electrode was varied by adjusting the concentration of glucose by the viable HT technique. Notably, the hybrid CMO-GC-2 achieved a maximum specific capacity of 851.85 C g-1 at 1 A g-1, and it is relatively higher than that of CMO-NF (301.4 C g-1). The asymmetric supercapacitor device (CMO-GC-2//AC) demonstrated excellent energy density (36.86 W h kg-1 for 152.84 W kg-1), power density (3209.35 W kg-1 for 11.19 W h kg-1), and extensive capacity retention of 87% for up to 5000 cycles. The high performance is related to the synergetic effect of EDLC and the redox reaction, with nano-architecture and well-defined morphology of the electrode material.
提高过渡金属氧化物材料比容量和循环稳定性的关键是通过无粘结剂的方法将碳化合物与超级电容器的杂化。由于具有高比表面积和导电性，碳质化合物缩短了电子-离子的扩散途径。在此，我们专注于通过引入纳米级碳材料来提高电极的比能、稳定性和导电性。将来自可再生环保葡萄糖的纳米碳与 CoMoO4 结合，提高了电极的实验比容量。通过可行的水热（HT）方法进行广泛的优化过程后，确认在泡沫镍上自生的 CoMoO4（CMO-NF）是最佳方法。通过可行的 HT 技术，调整葡萄糖浓度可以改变制备的 CoMoO4-葡萄糖衍生碳（CMO-GC）电极上的碳沉积量和结构形态。值得注意的是，杂化 CMO-GC-2 在 1 A g-1时达到了 851.85 C g-1的最大比容量，相对高于 CMO-NF（301.4 C g-1）。不对称超级电容器器件（CMO-GC-2//AC）表现出优异的能量密度（36.86 W h kg-1，对应 152.84 W kg-1的功率密度）和功率密度（3209.35 W kg-1，对应 11.19 W h kg-1的能量密度），以及高达 5000 次循环的 87%的容量保持率。高性能与电极材料的纳米结构和明确定义的形态以及 EDLC 和氧化还原反应的协同效应有关。
