Unlocking the Potential of Oxygen-Deficient Copper-Doped Co3O4 Nanocrystals Confined in Carbon as an Advanced Electrode for Flexible Solid-State Supercapacitors
Unlocking the Potential of Oxygen-Deficient Copper-Doped Co3O4 Nanocrystals Confined in Carbon as an Advanced Electrode for Flexible Solid-State Supercapacitors
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DOI：
10.1021/acsenergylett.1c01373
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发表时间：
2021-08-05
影响因子：
22
通讯作者：
Yamauchi, Yusuke
中科院分区：
文献类型：
--
作者：
Liu, Shude;Kang, Ling;Yamauchi, Yusuke
用于超级电容器的电池型材料由于其高能量密度而吸引了越来越多的研究兴趣。然而，它们差的电极动力学严重限制了电极表面上氧化还原活性位点的利用，导致低于标准的电化学性能。本文中，我们将Cu掺杂剂和O空位结合到限制在碳基质中的Co 3 O 4纳米晶体（O-v-Cu-Co 3 O 4 @C）中，其组装成纳米线。这种具有多功能纳米几何形状的异质结构体系结构提供了高度的组分间协同作用，使活性物质具有高度的可及性。此外，在O-v-Cu-Co 3 O 4 @C中的Cu掺杂剂和O空位协同操纵电子状态，并提供更多可接近的活性位点，导致增强的导电性和丰富的氧化还原化学。O-v-Cu-Co 3 O 4 @C的比容量和倍率性能显著提高，超过Co3O4@C。具有O-v-Cu-Co 3 O 4 @C的非对称超级电容器在800 W kg（-1）下提供64.1 W h kg（-1）的高能量密度，表现出良好的柔性，在不同弯曲状态下没有显著的性能下降。
Battery-type materials for supercapacitors have attracted increasing research interest owing to their high energy density. However, their poor electrode kinetics severely limit the utilization of redox-active sites on the electrode surface, resulting in subpar electrochemical performance. Herein, we incorporate both Cu dopants and O vacancies into Co3O4 nanocrystals confined in a carbon matrix (O-v-Cu-Co3O4@C) which are assembled into nanowires. This heterostructured architecture with multifunctional nanogeometries provides a high intercomponent synergy, enabling high accessibility to active species. Moreover, the Cu dopants and O vacancies in O-v-Cu-Co3O4@C synergistically manipulate the electronic states and provide more accessible active sites, resulting in enhanced electrical conductivity and enriched redox chemistry. The O-v-Cu-Co3O4@C achieves a significantly improved specific capacity and rate performance, exceeding those of Co3O4@C. The asymmetric supercapacitors with O-v-Cu-Co3O4@C deliver a high energy density of 64.1 W h kg(-1) at 800 W kg(-1), exhibiting good flexibility without significant performance degradation under different bending states.