Carbon-Coated Aluminium Current Collectors for New Li-Ion Battery Generation

Abstract

Since 2015, ARMOR has been designing and producing coated current collectors for lithium-ion batteries and super-capacitors. The En’Safe® technology (represented in Figure 1) uses a thin conductive coating made of carbon and polymer deposited on a metallic substrate. The presence of this thin layer results in lower contact resistance and improved adhesion between the substrate and the electrode which ultimately allows for improved power performances and better cyclability of these energy storage systems (1).At the industrial scale, the deployment of high-voltage positive material (such as LiNi0,5Mn1,5O4) for new Li-ion battery generation is still facing many issues. Indeed, the different cell components of the positive side can suffer from degradation when polarized at high voltage and high performances are still not achieved. According to our extended investigation, the use of imide-based lithium supporting salts (LiTFSI or LiFSI) is very promising for next generation battery as it is much safer than LiPF6 and enable to stabilize the positive electrode/electrolyte interface, However, traditional aluminium current collector suffers from severe oxidation from 3.7 V vs. Li+/Li in such media.In this contribution, we will present the new challenges facing ARMOR coated current collectors for next generation lithium-ion batteries with special emphasis on aluminium stability when polarized at high voltage in Al3+-complexing electrolyte media. We will show that the ARMOR coating effectively suppresses aluminium oxidation without any additive or change in solvent. In addition, we are also developing novel aluminium coatings stable enough up to 5 V vs. Li+/Li in order to ensure a high electronic conduction and a long time life of the positive current collector.(1) C. Busson et al., Journal of Power Sources 406 (2018) 7. Figure 1