School of Materials and Chemistry, University of Shanghai for Science and Technology, Jungong Road 334#, 200093 Shanghai, China.
School of Materials and Chemistry, University of Shanghai for Science and Technology, Jungong Road 334#, 200093 Shanghai, China.
J Colloid Interface Sci. 2023 Jul;641:510-520. doi: 10.1016/j.jcis.2023.03.081. Epub 2023 Mar 17.
Metal doping and electrochemical reconstruction had been demonstrated to play a significant role in the preparation of advanced electrode materials, which is helpful to achieve high-performance supercapacitors. However, there was no report about the combination of two technologies to construct electrode materials and their applications in supercapacitors. Herein, a rational Mn doped NiCo sulfide compound with open structure composed of 2D ultra-thin nanosheets was designed via a Mn doping route. In order to further improve the energy storage performance of the resulted product, we adopted a simple electrochemical activation strategy to reconstruct it. It was found that the reconstructed sample not only exhibited an irreversible evolution of structure (from 2D sheet to 3D channel), but also the phase transformation (from metal sulfide to metal hydroxide). Benefiting from the stable 3D curved structure with numerous channels, multitudinous charge transfer provided by numerous valence states of metals and copious active sites by low crystalline state, the in-situ self-reconstructed sample exhibited superior capacitance. In details, the optimized product delivered excellent specific capacitance of 1462C g (3655F/g) at 1 A g and high rate capability of 66 % even at 5 A g. Moreover, the corresponding assembled asymmetric supercapacitor exhibited an excellent energy density of 141.8 Wh kg at a power density of 850.1 W kg, and the capacitance retention rate was 96.6 % even after 5000 cycles, which was distinctly superior than thoseofthe previous similarmaterialsreported. In a word, this work provided a feasible and effective strategy to construct 3D Mn doped NiCo hydroxide electrode materials toward high-performance supercapacitors.
金属掺杂和电化学重构在先进电极材料的制备中发挥了重要作用，有助于实现高性能超级电容器。然而，目前还没有关于这两种技术结合构建电极材料及其在超级电容器中的应用的报道。在此，通过 Mn 掺杂路线设计了一种由 2D 超薄纳米片组成的具有开放结构的理性 Mn 掺杂 NiCo 硫化物化合物。为了进一步提高所得产物的储能性能，我们采用了一种简单的电化学激活策略对其进行重构。结果发现，重构后的样品不仅表现出结构的不可逆演变（从 2D 片到 3D 通道），而且还发生了相转变（从金属硫化物到金属氢氧化物）。得益于具有大量通道的稳定 3D 弯曲结构、金属的多种价态提供的众多电荷转移以及低结晶态提供的丰富活性位点，原位自重构样品表现出优异的电容性能。具体而言，优化后的产物在 1 A g 下表现出 1462C g（3655F/g）的优异比电容和 66%的高倍率性能，即使在 5 A g 下也能保持 66%的比电容。此外，相应组装的不对称超级电容器在 850.1 W kg 的功率密度下表现出 141.8 Wh kg 的优异能量密度，并且在 5000 次循环后电容保持率为 96.6%，明显优于之前报道的类似材料。总之，本工作为构建高性能超级电容器的 3D Mn 掺杂 NiCo 氢氧化物电极材料提供了一种可行且有效的策略。
