Hierarchical Cobalt-Nickel Double Hydroxide Arrays Assembled on Naturally Sedimented Ti3C2Tx for High-Performance Flexible Supercapacitors
Hierarchical Cobalt-Nickel Double Hydroxide Arrays Assembled on Naturally Sedimented Ti3C2Tx for High-Performance Flexible Supercapacitors
复制标题
在自然沉积的 Ti3C2TX 上组装的分层钴镍双氢氧化物阵列，用于高性能柔性超级电容器
DOI：
10.1002/adsu.202100371
复制
发表时间：
2021-12-29
影响因子：
7.1
通讯作者：
Luo, Yongsong
中科院分区：
文献类型：
--
作者：
Bai, Zuxue;Zhang, Deyang;Luo, Yongsong
对于超级电容器来说，具有优良的储能和转换性能的柔性电极是超级电容器非常理想的材料。本文采用刻蚀-沉积-生长工艺在自然沉积的Ti3C2Tx薄膜上均匀地制备了钴镍双氢氧化物(CONI-DH)微纳米片阵列，形成了CONI-DH@Ti3C2Tx异质结构。自然沉积的Ti3C2Tx薄膜作为衬底，最大限度地减少了CONI-DH纳米阵列的聚集，从而提高了导电性。此外，由CONI-DH互连的纳米阵列组成的分级结构促进了电解液的访问。利用其优良的导电性和较高的理论比电容，该电极在1Ag(-1)时具有919.5 Fg(-1)的高比电容，在20Ag(-1)下循环5000次后容量保持率高达89.6%。通过密度泛函理论计算研究了Ti3C2Tx和Ti3C2Tx的电荷密度差和偏态密度，理论计算表明Ti3C2Tx和Ti3C2Tx之间的化学键对电荷输运、电导和结构稳定性起着关键作用。
Flexible electrodes with excellent energy storage and conversion properties that can be produced by a simple process are highly desirable for supercapacitors. Herein, Cobalt-Nickel double hydroxide (CoNi-DH) micro-nanosheet arrays are prepared uniformly on naturally sedimented Ti3C2Tx films by an etching-deposition-growth process to form a CoNi-DH@Ti3C2Tx heterostructure. The naturally sedimented Ti3C2Tx film serves as the substrate to minimize aggregation of the CoNi-DH nanoarrays to enhance the electrical conductivity. Furthermore, the hierarchical structure comprised of the CoNi-DH interconnected nanoarrays promotes electrolyte access. By taking advantage of the excellent electrical conduction and high theoretical specific capacitance, the flexible CoNi-DH@Ti3C2Tx electrode in the supercapacitor delivers a superior specific capacitance of 919.5 F g(-1) at 1 A g(-1), and remarkable capacitance retention of 89.6% after 5000 cycles at 20 A g(-1). Density-functional theory calculations are performed to investigate the charge density difference and partial density of states of CoNi-DH@Ti3C2Tx and the theoretical assessment suggests that the chemical bonds between Ti3C2Tx and CoNi-DH are critical to the charge transport, electrical conductivity, and structural stability.