State Key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and Engineering, Northwestern Polytechnical University and Shaanxi Joint Laboratory of Graphene (NPU) , Xi'an 710072, China.
University Research Facility in Materials Characterization and Device Fabrication, The Hong Kong Polytechnic University , Hong Kong 999077, China.
ACS Appl Mater Interfaces. 2016 Oct 5;8(39):26091-26097. doi: 10.1021/acsami.6b09031. Epub 2016 Sep 26.
Owing to its ultrahigh specific capacity and low electrochemical potential, lithium (Li) metal is regarded as one of the most attractive anode materials for next-generation lithium batteries. Nevertheless, the commercialization of Li-metal-based rechargeable batteries (LiMBs) has been retarded by the uncontrollable growth of Li dendrites, as well as the resulting poor cycle stability and safety hazards. In this work, a 3D graphene@Ni scaffold has been proposed to accomplish dendrite-free Li deposition via structural and interfacial synergistic effects. Due to the intrinsic high surface area used to reduce the effective electrode current density and the surface-coated graphene working as an artificial protection layer to provide high cycle stability as well as suppress the growth of Li dendrites, the Coulombic efficiencies of Li deposition on 3D graphene@Ni foam after 100 cycles can be sustained as high as 96, 98, and 92% at the current densities of 0.25, 0.5, and 1.0 mA cm, respectively, which shows more excellent cycle stability than that of its planar Cu foil and bare Ni foam counterparts. The results obtained here demonstrate that the comprehensive consideration of multiaspect factors could be more help to enhance the performance of Li metal anode so as to achieve its real application in next-generation LiMBs.
由于其超高的比容量和低电化学势,金属锂(Li)被认为是下一代锂电池最有吸引力的阳极材料之一。然而,由于 Li 枝晶的不可控生长,以及由此导致的循环稳定性差和安全隐患,基于 Li 金属的可充电电池(LiMBs)的商业化一直受到阻碍。在这项工作中,提出了一种 3D 石墨烯@Ni 骨架,通过结构和界面协同效应实现无枝晶 Li 沉积。由于高表面积可降低有效电极电流密度,以及表面涂覆的石墨烯作为人工保护层提供高循环稳定性并抑制 Li 枝晶的生长,在电流密度为 0.25、0.5 和 1.0 mA cm 时,3D 石墨烯@Ni 泡沫上 Li 沉积的库仑效率在 100 次循环后可分别保持在 96%、98%和 92%,这显示出比其平面 Cu 箔和裸 Ni 泡沫对照物更优异的循环稳定性。这里得到的结果表明,综合考虑多方面因素可以更有助于提高 Li 金属阳极的性能,从而实现其在下一代 LiMBs 中的实际应用。