Li Host Carbon Materials As the Negative Electrode for a Li-Metal Battery – Mechanistic and Practical Assessment

Abstract

The lithium metal anode is highly valued in the development of high-energy density storage devices owing to its high specific capacity. However, the growth of lithium dendrites and high-volume expansion during the charging process creates significant issues for commercial application. To regulate the lithium deposition behavior various methods have been proposed among which carbon-based materials are being widely investigated because of their unique advantages including high conductivity, along with the material availability and ease of operation. However, current literature on lithium deposition in carbonaceous hosts have contradictory conclusions and further investigation is needed1–4.Herein, pure hollow core-carbon spheres (PHCCSs), deposited on copper foil (PHCCS@Cu), are used to study the lithium deposition behavior with respect to this type of structure. It is demonstrated that lithium shows some initial and limited intercalation into the PHCCSs and then plates on its external walls and the top-surface of the hollow core carbon structures during the charging process. Figure 1 shows initial lithium insertion followed by lithium deposition with a greater amount of charging. A possible mechanism of lithium deposition inside the PHCCSs is discussed from the aspect of lithium-ion transport and lithium deposition site preference. The application potential of PHCCSs from the point of view of lithium metal volumetric capacity (VC) are also discussed. References G. Zheng et al., Nat. Nanotechnol., 9, 618–623 (2014) http://dx.doi.org/10.1038/nnano.2014.152.D. Lin et al., Nat. Nanotechnol., 11 (2016).K. Yan et al., Nat. Energy, 1, 16010 (2016).W. Ye et al., Adv. Energy Mater., 10, 1–10 (2020). Figure 1