Shi Haodong, Qin Jieqiong, Huang Kai, Lu Pengfei, Zhang Chuanfang John, Dong Yanfeng, Ye Mao, Liu Zhongmin, Wu Zhong-Shuai
Dalian National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, P. R. China.
University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.
Angew Chem Int Ed Engl. 2020 Jul 13;59(29):12147-12153. doi: 10.1002/anie.202004284. Epub 2020 May 18.
Guiding the lithium ion (Li-ion) transport for homogeneous, dispersive distribution is crucial for dendrite-free Li anodes with high current density and long-term cyclability, but remains challenging for the unavailable well-designed nanostructures. Herein, we propose a two-dimensional (2D) heterostructure composed of defective graphene oxide (GO) clipped on mesoporous polypyrrole (mPPy) as a dual-functional Li-ion redistributor to regulate the stepwise Li-ion distribution and Li deposition for extremely stable, dendrite-free Li anodes. Owing to the synergy between the Li-ion transport nanochannels of mPPy and the Li-ion nanosieves of defective GO, the 2D mPPy-GO heterostructure achieves ultralong cycling stability (1000 cycles), even tests at 0 and 50 °C, and an ultralow overpotential of 70 mV at a high current density of 10.0 mA cm , outperforming most reported Li anodes. Furthermore, mPPy-GO-Li/LiCoO full batteries demonstrate remarkably enhanced performance with a capacity retention of >90 % after 450 cycles. Therefore, this work opens many opportunities for creating 2D heterostructures for high-energy-density Li metal batteries.
引导锂离子均匀、分散地传输对于具有高电流密度和长期循环稳定性的无枝晶锂负极至关重要，但对于缺乏精心设计的纳米结构而言仍具有挑战性。在此，我们提出一种由夹在介孔聚吡咯（mPPy）上的缺陷氧化石墨烯（GO）组成的二维（2D）异质结构，作为一种双功能锂离子再分配器，用于调节逐步的锂离子分布和锂沉积，以实现极其稳定、无枝晶的锂负极。由于mPPy的锂离子传输纳米通道与缺陷GO的锂离子纳米筛之间的协同作用，二维mPPy-GO异质结构实现了超长的循环稳定性（1000次循环），甚至在0和50°C下进行测试，并且在10.0 mA cm的高电流密度下具有70 mV的超低过电位，优于大多数已报道的锂负极。此外，mPPy-GO-Li/LiCoO全电池表现出显著增强的性能，在450次循环后容量保持率>90%。因此，这项工作为制造用于高能量密度锂金属电池的二维异质结构开辟了许多机会。
