Crumpled Graphene Balls Stabilized Dendrite-free Lithium Metal Anodes Shan Liu, Aoxuan Wang, Qianqian Li, Jinsong Wu, Kevin Chiou, Jiaxing Huang, Jiayan Luo  Joule  Volume 2, Issue 1, Pages 184-193 (January 2018) DOI: 10.1016/j.joule.2017.11.004 Copyright © 2017 Elsevier Inc. Terms and Conditions

Joule 2018 2, 184-193DOI: (10.1016/j.joule.2017.11.004) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 1 Characterization of Crumpled Graphene Balls (A–C) Scanning EM images (A and B) and N2 adsorption-desorption isotherms and pore-size distribution of crumpled graphene balls (CGB) (C). (D) Schematic drawing illustrating the configuration of the in situ TEM cell. (E) TEM snapshot images taken during the lithiation process in a CGB. (F) Schematic showing that CGB can support high loading of Li metal without experiencing high volume fluctuation. Further Li deposition on top of the CGB electrode does not experience dendrite growth. See also Figures S1–S4. Joule 2018 2, 184-193DOI: (10.1016/j.joule.2017.11.004) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 2 Scalable Li Loading in Crumpled Graphene Balls without Experiencing High Volume Fluctuation (A and B) Representative (A) cross-section and (B) top-view scanning EM images of mossy dendrites grown on planar Cu substrate after depositing 0.75 mA hr cm−2 of Li. (C and D) Representative cross-section scanning EM images of 8-μm thick crumpled graphene ball (CGB)-coated Cu before (C) and after (D) depositing 0.75 mA hr cm−2 of Li. (E and F) Representative cross-section scanning EM images of 40-μm thick CGB-coated Cu before (E) and after (F) depositing 3.75 mA hr cm−2 of Li. (G and H) Representative cross-section scanning EM images of 120-μm thick CGB-coated Cu before (G) and after (H) depositing 10 mA hr cm−2 of Li. (I) Top-view scanning EM image of 120-μm thick CGB-coated Cu after depositing 10 mA hr cm−2 of Li. Insets of (A) and (D) show the enlarged images. See also Figures S5 and S6. Joule 2018 2, 184-193DOI: (10.1016/j.joule.2017.11.004) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 3 Dendrite-free High Amount of Li Grown on Top of Crumpled Graphene Ball Electrodes (A) Li (3 mA hr cm−2) deposited on 8-μm thick crumpled graphene ball (CGB) electrode. (B and C) Li deposited on a 40-μm thick CGB electrode at (B) 6 mA hr cm−2 and (C) 12 mA hr cm−2. Joule 2018 2, 184-193DOI: (10.1016/j.joule.2017.11.004) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 4 Electrochemical Performance of the Crumpled Graphene Ball Electrodes for Li Metal Anodes (A and C) The first 50 cycling Columbic efficiency of the crumpled graphene ball (CGB) electrodes and the controlled Cu electrodes with Li deposition amount of (A) 0.5 mA hr cm−2 and (C) 1 mA hr cm−2 in each cycle at different current rates. (B and D) The corresponding average Columbic efficiency and its variance are presented in (B) and (D) for (A) and (C), respectively. (E) Columbic efficiency of CGB electrodes and bare Cu electrodes with Li deposition amount of 0.5 mA hr cm−2 at a current rate of 0.5 mA cm−2. See also Figures S7 and S8. Joule 2018 2, 184-193DOI: (10.1016/j.joule.2017.11.004) Copyright © 2017 Elsevier Inc. Terms and Conditions

Figure 5 Electrochemical Performance of the Crumpled Graphene Ball Electrodes for Li Metal Anodes (A) Coulombic efficiency of crumpled graphene ball (CGB) and Cu electrodes with increasing current densities and capacities. Li was plated for 30 min at each cycle with a certain current density and then stripped away up to 1.0 V. (B) Coulombic efficiency of CGB electrode with increasing capacities. The current density was 1 mA cm−2 and the stripping-up voltage was 1 V. (C) Plating-stripping curves of Cu electrode with increasing capacities. The current density was 1 mA cm−2 and the stripping-up voltage was 1 V. (D) Galvanostatic cycling of symmetric Li@CGB and Li@Cu cells. The current density was fixed at 0.5 mA cm−2 with each cycle set to 2 hr. See also Figures S9–S15. Joule 2018 2, 184-193DOI: (10.1016/j.joule.2017.11.004) Copyright © 2017 Elsevier Inc. Terms and Conditions