High-capacity, low-tortuosity, and channel-guided lithium metal anode

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 114; no. 14; pp. 3584 - 3589
• Main Authors: Zhang, Ying, Luo, Wei, Wang, Chengwei, Li, Yiju, Chen, Chaoji, Song, Jianwei, Dai, Jiaqi, Hitz, Emily M., Xu, Shaomao, Yang, Chunpeng, Wang, Yanbin, Hu, Liangbing
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 04.04.2017; National Academy of Sciences, Washington, DC (United States)
• Subjects: Batteries; bio-inspired; charge transport; defects; Electrodes; Electrolytes; ENERGY STORAGE; energy storage (including batteries and capacitors); Lithium; lithium metal batteries; low tortuosity; MATERIALS SCIENCE; Metals; Physical Sciences; Porosity; synthesis (novel materials); synthesis (scalable processing); synthesis (self-assembly); wood channels; stable cycling; wood channels; high capacity; low tortuosity; lithium metal batteries
• ISSN: 0027-8424; 1091-6490; 1091-6490
• DOI: 10.1073/pnas.1618871114

Lithium metal anode with the highest capacity and lowest anode potential is extremely attractive to battery technologies, but infinite volume change during the Li stripping/plating process results in cracks and fractures of the solid electrolyte interphase, low Coulombic efficiency, and dendritic growth of Li. Here, we use a carbonized wood (C-wood) as a 3D, highly porous (73% porosity) conductive framework with well-aligned channels as Li host material. We discovered that molten Li metal can infuse into the straight channels of C-wood to form a Li/C-wood electrode after surface treatment. The C-wood channels function as excellent guides in which the Li stripping/plating process can take place and effectively confine the volume change that occurs. Moreover, the local current density can be minimized due to the 3D C-wood framework. Therefore, in symmetric cells, the as-prepared Li/C-wood electrode presents a lower overpotential (90 mV at 3 mA·cm−2), more-stable stripping/plating profiles, and better cycling performance (∼150 h at 3 mA·cm−2) compared with bare Li metal electrode. Our findings may open up a solution for fabricating stable Li metal anode, which further facilitates future application of high-energy-density Li metal batteries.