Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences , Ningbo 315201 , China.
ACS Appl Mater Interfaces. 2019 Nov 27;11(47):44383-44389. doi: 10.1021/acsami.9b17108. Epub 2019 Nov 13.
Graphene has been wildly used as a host to suppress dendrite growth to stabilize the lithium metal anode. However, the high overpotential of lithium deposition on pure graphene has to be lowered by doping or employing precious metals. Additionally, the soft nature of graphene rendered itself to aggregate, consequently squeezing room for lithium accommodation. Herein, a tough graphene framework composed of 3D periodic hollow spheres was reported as a free-standing host to stabilize lithium metal anodes. The prepared 3D periodic hollow structure not merely reinforces the framework to maintain hollow structure under pressure caused by assembling battery, but also lowers the overpotential without the help of dopant or precious metals. It is worthy to note that high efficiency of ion diffusion, thanks to the channels interconnecting hollow spheres by holes on the walls, benefits both suppression of lithium dendrite and rate capability. The properties of low density and high mechanical strength make graphene frameworks electrode a promising lightweight Li host material, which reveals a new avenue for designing high-energy density electrode materials.
石墨烯被广泛用作宿主来抑制枝晶生长以稳定锂金属阳极。然而，纯石墨烯上锂沉积的高过电位必须通过掺杂或使用贵金属来降低。此外，石墨烯的柔软性质使其易于聚集，从而挤压了容纳锂的空间。在此，报道了一种由 3D 周期性空心球组成的坚韧石墨烯框架，作为一种独立的宿主来稳定锂金属阳极。所制备的 3D 周期性空心结构不仅增强了框架在电池组装过程中因受压而导致的空心结构的稳定性，而且无需掺杂剂或贵金属的帮助就降低了过电位。值得注意的是，得益于壁上的孔将空心球相互连接的通道，高离子扩散效率有利于抑制锂枝晶和提高倍率性能。低密度和高强度的特性使石墨烯框架电极成为一种有前途的轻质 Li 宿主材料，为设计高能量密度电极材料开辟了新途径。
