Hierarchically porous CuO nano-labyrinths as binder-free anodes for long-life and high-rate lithium ion batteries
Hierarchically porous CuO nano-labyrinths as binder-free anodes for long-life and high-rate lithium ion batteries
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DOI：
10.1016/j.nanoen.2019.01.081
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发表时间：
2019-05-01
期刊：
影响因子：
17.6
通讯作者：
Lin, Zhiqun
中科院分区：
文献类型：
--
作者：
Jia, Songru;Wang, Yang;Lin, Zhiqun
合理设计具有互连纳米结构的无粘合剂电极材料的能力对于具有长循环和优异倍率性能的锂离子电池（LIB）是高度期望的。这种在纳米结构之间含有孔的电极赋予与电解质的大面积接触、与集流体的改善的导电性以及良好的结构稳定性和机械完整性。在此，我们首次报道了CuO电极在LIB中的出色循环稳定性和倍率性能。通过一种简单的溶液刻蚀工艺在铜箔上制备了由密集交错排列的纳米颗粒组成的CuO纳米颗粒。值得注意的是，发现宏观和介观孔分别普遍存在于相邻的CuO层之间和层内（即，形成分级多孔的CuO NL）。有趣的是，CuO NLS阳极产生超长的循环稳定性，即，在800次循环后的比容量为320 mA h g（-1），而在1 A g（-1）的高电流密度下没有容量衰减，并且具有出色的高倍率性能（高达30 C）。这是分层孔和交错纳米结构的独特协同效应的直接结果。此外，通过在CuO纳米线表面沉积Si薄膜，实现了可逆容量的进一步提高。这种具有分层孔的交错的含金属结构代表了一种重要类型的架构，其支持用于长循环寿命能量存储装置的电极材料的开发。
The ability to rationally design binder-free electrode materials that possess interconnected nanostructures is highly desirable for lithium-ion batteries (LIBs) with long cycling and excellent rate performances. Such electrode containing pores between nanostructures imparts large-area contact with electrolyte, improved electrical conductivity with current collector, and good structural stability and mechanical integrity. Herein, we report, for the first time, outstanding cycling stability and rate performance of CuO electrode in LIBs. CuO nano-labyrinths (NLs) composed of densely interlaced nanowalls on Cu foil are crafted via a facile solution-based etching process. It is notable that macroscopic and mesoscopic pores are found to ubiquitously present among the adjacent CuO nanowalls and within the nanowall, respectively (i.e., forming hierarchically porous CuO NLs). Intriguingly, CuO NLs anodes yield an ultralong cycling stability, that is, a specific capacity of 320 mA h g(-1) after 800 cycles without the capacity fading at high current density of 1 A g(-1), and an outstanding high-rate performance (up to 30 C). This is a direct consequence of unique synergistic effects of hierarchical pores and interlaced nanostructures. Moreover, a further enhancement of reversible capacity is achieved by deposition Si thin film on the surface of CuO NLs. Such interlaced nanowall-containing structures with hierarchical pores represent an important type of architectures that underpin the development of electrode materials for long cycle-life energy storage devices.