Gradient lithiation to load controllable, high utilization lithium in graphitic carbon host for high-energy batteries. (March 2022)

• Record Type: Journal Article
• Authors: Tao, Lei; Ma, Bingyuan; Luo, Fenqiang; Xu, Zhengrui; Zheng, Zhifeng; Huang, Haibo; Bai, Peng; Lin, Feng
• Is Part Of: Nano energy. Volume 93(2022)
• Publication Date: 2022-03
• Subjects: Graphitic carbon paper -- Thermal infiltration -- Gradient lithiation -- Dendrite-free -- Li metal batteries; Nanoscience -- Periodicals; Nanotechnology -- Periodicals; Nanostructured materials -- Periodicals; Power resources -- Technological innovations -- Periodicals; Nanoscience; Nanostructured materials; Nanotechnology; Power resources -- Technological innovations; Periodicals; 621.042
• DOI: 10.1016/j.nanoen.2021.106808
• Languages: English
• ISSNs: 2211-2855

Abstract

Abstract: The multiphase interaction between Li metal and carbon materials provides great opportunities to design advanced composite anodes for Li metal batteries. Herein, we report the conversion of single-sheet graphitic carbon papers (CPs) to function-gradient Li/C composite anodes with controllable formations of LiC6 and Li metal through controlling the thermal infiltration time. The uniform and dense lithiophilic LiC6 is formed first and gradually covers the entire CP host, which promotes the subsequent homogeneous infiltration of metallic Li into the CP. The resulting composite anode has a unique gradient structure, with one example consisting of a lithiated LiC6 coating of 5.8 mAh cm −2 and a thin Li bottom layer of 2.7 mAh cm −2 . Such a gradient composite structure allows for the selective utilization of Li metal and LiC6 as the active component under different electrochemical conditions. This composite anode, with a much leaner Li loading than many reported Li/C composite anodes, has a stable porous framework and abundant lithiophilic sites, which enables uniform local electric field and stable Li metal deposition during cycling. Paired with high-capacity cathodes, the composite anode, with only a fraction of Li metal loading compared to Li foil, can provide better long-term cycling stability, and higher rate capability. Graphical Abstract: ga1 A unique gradient lithiated electrode is achieved by directly contacting the carbon paper with molten Li. Paired with high-capacity cathodes, the gradient anode, with only a fraction of Li metal loading compared to Li foil, can provide better long-term cycling stability. Highlights: The multiphase interaction between Li metal and carbon paper promotes the formation of a gradient lithiation electrode. Such gradient electrode retains a stable framework and abundant lithiophilic sites to promote stable Li plating/stripping. The gradient electrode allows for the selective utilization of Li metal under different electrochemical conditions. The gradient electrode exhibits better long-term cycling stability and higher rate capability compared to the Li foil.