Brush-Like Cobalt Nitride Anchored Carbon Nanofiber Membrane: Current Collector-Catalyst Integrated Cathode for Long Cycle Li-O2 Batteries.
Brush-Like Cobalt Nitride Anchored Carbon Nanofiber Membrane: Current Collector-Catalyst Integrated Cathode for Long Cycle Li-O2 Batteries.
复制标题
DOI：
10.1021/acsnano.7b03794
复制
发表时间：
2017-12
期刊：
影响因子：
17.1
通讯作者：
K. Yoon;Kihyun Shin;Jiwon Park;Su-Ho Cho;Chanhoon Kim;Ji-Won Jung;J. Cheong;H. Byon;Hyuk Mo Lee-Hy
中科院分区：
文献类型：
--
作者：
K. Yoon;Kihyun Shin;Jiwon Park;Su-Ho Cho;Chanhoon Kim;Ji-Won Jung;J. Cheong;H. Byon;Hyuk Mo Lee-Hy
为了实现锂氧（Li-O2）电池的高可逆性和长循环寿命，应克服Li2O2的不可逆形成、不可避免的副反应以及阴极界面的电荷传输不良等问题。在这里，我们报告了一种合理的空气阴极设计，使用氮化钴（Co4N）功能化碳纳米纤维（CNF）膜作为集流体-催化剂集成空气阴极。通过 Co(OH)F 纳米棒的水热生长和氮化步骤，刷状 Co4N 纳米棒均匀锚定在导电静电纺丝 CNF 纸上。 Co4N 修饰的 CNF (Co4N/CNF) 正极在 Li-O2 电池中表现出优异的电化学性能和超过 177 个循环的出色稳定性。在循环过程中，金属 Co4N 纳米棒在整个连续网络化的 CNF 中提供了足够的可访问反应位点以及便捷的电子传输路径。此外，Co4N纳米棒表面形成的薄氧化层（<10 nm）促进了薄膜型Li2O2的可逆形成/分解，导致过电位间隙显着减小（700 mAh g-1时约1.23 V）。此外，使用Co4N/CNF阴极的袋式锂空气电池即使在180°弯曲下也能在真实空气中稳定运行。结果表明，反应产物的有利形成/分解和副反应的介导在很大程度上取决于阴极材料的合适表面化学和定制结构，这对于真正的锂空气电池应用至关重要。
To achieve a high reversibility and long cycle life for lithium-oxygen (Li-O2) batteries, the irreversible formation of Li2O2, inevitable side reactions, and poor charge transport at the cathode interfaces should be overcome. Here, we report a rational design of air cathode using a cobalt nitride (Co4N) functionalized carbon nanofiber (CNF) membrane as current collector-catalyst integrated air cathode. Brush-like Co4N nanorods are uniformly anchored on conductive electrospun CNF papers via hydrothermal growth of Co(OH)F nanorods followed by nitridation step. Co4N-decorated CNF (Co4N/CNF) cathode exhibited excellent electrochemical performance with outstanding stability for over 177 cycles in Li-O2 cells. During cycling, metallic Co4N nanorods provide sufficient accessible reaction sites as well as facile electron transport pathway throughout the continuously networked CNF. Furthermore, thin oxide layer (<10 nm) formed on the surface of Co4N nanorods promote reversible formation/decomposition of film-type Li2O2, leading to significant reduction in overpotential gap (∼1.23 V at 700 mAh g-1). Moreover, pouch-type Li-air cells using Co4N/CNF cathode stably operated in real air atmosphere even under 180° bending. The results demonstrate that the favorable formation/decomposition of reaction products and mediation of side reactions are hugely governed by the suitable surface chemistry and tailored structure of cathode materials, which are essential for real Li-air battery applications.