中北大学《JMAT》：以钴酸铜为电极的超级电容器的前世今生！

A review on the synthesis of CuCo2O4-based electrode materials and their applications in supercapacitors

导 读

中北大学陈慧玉教授团队在Journal of Materiomics第7卷第1期发表了题目为“A review on the synthesis of CuCo2O4-based electrode materials and their applications in supercapacitors”的综述论文。

论文综合分析了CuCo2O4的晶体结构以及在超级电容器应用中的优势和目前存在的问题。全文主要包括：1. 总结形成 CuCo2O4 基电极材料的多种手段；2. 比较和总结了不同 CuCo2O4基电极材料的容量和生命周期；3. 提出并讨论了提高 CuCo2O4基电极材料电容性能的可行方案等几个方面。最后总结并综述了用于超级电容器的 CuCo2O4及其复合材料的最新进展，提出超级电容器在应用中的研究进展和未来发展趋势。

DOI:10.1016/j.jmat.2020.07.013

Highlights

·Recent advances of CuCo2O4 and its composites for supercapacitors are reviewed.

·Formation of CuCo2O4-based electrode materials by various methods are summarized.

·Capacity and life cycles of different CuCo2O4-based electrode materials are compared and summarized.

·The possible ways to enhance the capacitive performance of CuCo2O4-based electrode materials are discussed.

·Directions for future research on CuCo2O4-based electrode materials are proposed.

Graphical abstract

Sun J, Xu C, Chen H. A review on the synthesis of CuCo2O4-based electrode materials and their applications in supercapacitors[J]. J. Materiomics, 7(2021), pp. 98-126.

内 容 梗 概

电池型CuCo2O4电极材料因其理论比容量高、元素铜储量丰富、成本低等优点，近年来在超级电容器的应用中引起了广泛的研究兴趣。但是在实际应用中，CuCo2O4仍存在一些问题如电导率差、比容量不够理想、循环耐久性较差等缺点。全文综述了钴酸铜（CuCo2O4）电极材料的制备方法、以及在超级电容器应用中的研究进展和未来发展趋势。首先，从电池型CuCo2O4电极材料有望提升超级电容器比容量和能量密度的角度出发，综合分析了CuCo2O4的晶体结构以及在超级电容器应用中的优势和目前存在的问题；详细阐述了CuCo2O4电极材料的制备方法及电化学性能；对单一CuCo2O4电极材料（包括粉体和无粘结剂CuCo2O4）在超级电容器中的电化学性能表现进行详尽地总结与分析；之后，探讨了基于CuCo2O4复合电极材料在超级电容器中的电化学性能及最新进展；最后对CuCo2O4电极材料应用于超级电容器的未来发展方向进行总结和展望。

Fig.10. FE-SEM images of the CuCo2O4 with different morphologies, (a) nanosheets, (b) cubes, (c) compact granular, and (d) agglomerated structures. CuCo2O4 nanograss on copper foam: (e) schematic illustration of the fabrication processes, (f) and (g) low and high-magnification SEM images, (h) specific capacitance as a function of current density, and (i) cycling performance at 2 A g-1 and 8 A g-1 with the SEM image taken after 5000 cycles at 2 A g-1 (inset).

Fig.12.CuCo2O4/rGO composite: (a) schematic illustration for the preparation and (b) FESEM image. (c) Schematic illustration for the formation process of graphene-wrapped CuCo2O4 hollow spheres, FESEM images of (d) CuCo2O4 hollow spheres and (e) graphene-wrapped CuCo2O4 hollow spheres. (f) Rate capability and (g) long-term cycling performance of CuCo2O4 hollow spheres and graphene-wrapped CuCo2O4 hollow spheres, respectively.

Fig.16.(a) Schematic illustration for the synthetic route of heterostructural CuCo2O4/PPy. (b) SEM image of CuCo2O4/CuO@NiCo2S4 composites. (c) SEM image of the CNT-CuCo2O4@Ag sample, (d) specific capacity (mAh g-1) at different current density, and (e) cycling stability of the CuCo2O4, CNT-CuCo2O4, and CNT-CuCo2O4@Ag electrodes. Digital images of (f) the positive and negative electrodes used for fabrication of ASC device, (g) assembled ASC device, and (h) the two ASC devices in series glowing LEDs.

展 望

该综述详尽地总结了CuCo2O4电极材料的制备方法及在超级电容器应用方面的研究进展。尽管一些已报道的CuCo2O4及其复合电极材料在超级电容器上表现出较好的性能，但以下几方面仍可进一步研究和改进：

（1）一些基本概念不能混淆，CuCo2O4电极材料属于电池类材料而不是赝电容材料，其容量的表述应该是比容量（C g-1或mAh g-1）而不是比电容（F g-1）。

（2）特殊中空结构的设计：可以通过MOF辅助或自模板方法，制备孔径尺寸和形貌可控的独特中空结构CuCo2O4电极材料，有望提高其电化学性能。

（3）可通过金属离子的掺杂产生氧空位来提高CuCo2O4的电导率，进而提升其电化学性能；或将CuCo2O4与其他高导电性材料如金属粒子、碳材料等复合来提高材料整体的导电性。

（4）负极材料的研究，通过制备和设计具有更高比电容和更宽电位窗口的负极（如rGO/Fe2O3、V2O5、Bi2O3等）以取代活性炭，可进一步提高超级电容器的能量密度。

（5）电解液的研究，有机电解液或离子液体电解液的使用可以增加电压窗口并进一步提高能量密度。此外，氧化还原电解质的使用（如KI、KBr、Na2MoO4、K3Fe(CN)6等）是改善超级电容器电化学性能的另一种可能策略。

（6）通过在活性材料和集流体之间引入缓冲层，以加强它们之间的接触，可以在一定程度上提高电极材料的导电性和循环稳定性。

作者介绍

Jiale Sunis currently a master candidate under the supervision of Prof. Huiyu Chen and Prof. Chunju Xu at the School of Materials Science and Engineering in North University of China. He received his bachelor’s degree from Zhengzhou University of Light Industry (China) in 2018. His current research interests are the controlled synthesis of porous transition metal oxides and their applications in supercapacitors.

Chunju Xuis an associate professor at the School of Materials Science and Engineering in North University of China. She received her PhD degree in Advanced Materials Science and Engineering from Sungkyunkwan University, South Korea (2012). Her current research interest focuses on the transition metal oxides based electrode materials and their applications in energy storage.

Huiyu Chenis currently an associate professor at the School of Materials Science and Engineering in North University of China. He received his PhD degree in Advanced Materials Science and Engineering from Sungkyunkwan University, South Korea (2011). He mainly works on inorganic nanomaterials, functional composites, and energy materials.

本文来自Journal of Materiomics（JMAT）。