3D Lattice‐Matching Layered Hydroxide Heterostructure with Improved Interfacial Charge Transfer and Ion Diffusion for High Energy Density Supercapacitor
3D Lattice‐Matching Layered Hydroxide Heterostructure with Improved Interfacial Charge Transfer and Ion Diffusion for High Energy Density Supercapacitor
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DOI：
10.1002/admi.202100429
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发表时间：
2021-06
影响因子：
5.4
通讯作者：
Huanji Liu;Juncheng Zhu;Dan Tian;Rodrigo P. Carvalho;Zhi-Ping Shi;Zhao Cai;Xinghua Chang;C. M. Araujo;Yu Zhou;Jiliang Zhu
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文献类型：
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作者：
Huanji Liu;Juncheng Zhu;Dan Tian;Rodrigo P. Carvalho;Zhi-Ping Shi;Zhao Cai;Xinghua Chang;C. M. Araujo;Yu Zhou;Jiliang Zhu
电化学电荷存储主要依赖于复杂界面和电极材料的电学性质以及离子在电解液中的动态扩散。化学成分可调的镍钴层状双氢氧化物(LDHs)是一种很有前途的电化学超级电容器材料，其理论性能可达3000Fg−1。然而，NiCo-LDHs的实验性能仍然受到电荷转移速率低和离子动态扩散速度慢的限制。在这里，外延生长了三维晶格匹配的Ni0.85Co0.15(OH)2@α-Co(OH)2异质结。实验结果和理论计算证实，这种三维异质结可以提高电荷转移能力，加速离子扩散。当Co(OH)2的最佳用量为20 mg(−-20)时，材料的比电容达到2480F g−1，在30A g nCC 1的大电流密度下保持了初始比容量的71%。在功率密度分别为0.79kW和0.78kW kg−1时，非对称纽扣器件和软包装器件的能量密度分别达到69.2Wh和65.7Wh kg−1，并且在10000次循环下分别保持了88%和80%的初始电容。总的设计原则清楚地说明了电化学界面和动态过程的重要性，为推动电化学器件的应用能力铺平了道路。
The electrochemical charge storage mostly relies on the electrical properties of complex interfaces and electrode materials as well as the dynamic ions diffusion in the electrolytes. Nickel‐cobalt layered double hydroxides (LDHs) with tunable chemical composition are promising for electrochemical supercapacitors, where the theoretical performance could be up to 3000 F g−1. However, the experimental performances of NiCo‐LDHs are still limited by low charge transfer rate and slow dynamic ions diffusion. Here, a 3D lattice matching Ni0.85Co0.15(OH)2@α‐Co(OH)2 heterostructure is epitaxially grown. The experimental results and theoretical calculation confirm that such a 3D heterostructure could improve charge transfer abilities and accelerated ions diffusion. The specific capacitance of 2480 F g−1 and retained 71% of the initial capacitance at high current density of 30 A g−1 have been achieved by optimal Co(OH)2 amount of 20 mg (NCC‐20). Asymmetric button devices and soft‐pack devices have been demonstrated with exceptional energy densities of 69.2 and 65.7 Wh kg−1 at power densities of 0.79 and 0.78 kW kg−1, and maintained 88% and 80% initial capacitance under 10 000 cycles, respectively. The general design principles clearly demonstrate the importance of electrochemical interface and dynamic process, paving the way to push forward the application capability of electrochemical devices.