Over the last two decades, post lithium ion battery chemistries with even higher power and energy density, compared to those of conventional lithium ion batteries with intercalation hosts, have been widely researched for application in large scale energy storage. Among various candidates, Li-O₂ battery is one of the most promising alternative chemistries, having a theoretical energy of 3505 Wh kg^-1 via plating and stripping of Li₂O₂ with an average working potential of 3 V vs. Li⁺/Li. However, Li-O₂ battery often shows insufficient areal capacity due to the insulating properties of thick Li₂O₂ layer.

Previously, our group reported the fabrication of a novel 3.3 μm thick 3D Ni nanomesh current collector, which shows excellent surface area to geometric footprint area ratio (100 cm²/1 cm²) and high theoretical porosity (76 %) with systematically controlled nanowire thickness via anodization of aluminum alloys (Fig. 1) [1, 2]. Thanks to its unique properties, the 3D Ni nanomesh qualifies as an excellent current collector candidate for reversible Li₂O₂ plating and stripping performance over large surface area with the enhanced areal capacity. In this study, we aimed to introduce amorphous carbon, one of the most studied electrode materials for Li-O₂ battery, as a coating material for 3D Ni nanomesh via low temperature PECVD technique. To investigate its potential application as an electrode for Li-O₂ battery, the galvanostatic charge and discharge profiles of glassy carbon and carbon-coated 3D Ni nanomesh are recorded with the discharging current rate of 0.1 mA cm^-2 and the balanced charging current rate of 0.05 mA cm^-2 under pure O₂ atmosphere. During the preliminary electrochemical measurement, we observed that the carbon-coated 3D Ni nanomesh showed greatly increased discharge and charge areal capacity than those of glassy carbon (102 and 563 times higher than those of glass carbon). In addition to the above-mentioned findings, the ex-situ STEM images of carbon-coated 3D Ni nanomesh after charging and discharging processes will further be discussed.

References

[1] J. Vanpaemel, A. Abd-Elnaiem, S. De Gendt, and P.M. Vereecken, J. Phys. Chem. C, 2015, 119, 2105-2112.

[2] S.P. Zankowski and P.M. Vereecken, ACS Appl. Mater. Interfaces, 2018, 10, 44634-44644.

Fig. 1. Brief description of 3D Ni nanomesh fabrication process and SEM images of as-prepared 3.3 μm thick 3D Ni nanomesh current collector template.