Aqueous Manufacturing of Defect-Free Thick Multi-Layer NMC811 Electrodes

Abstract

Manufacturing thick electrodes for Li-ion batteries is a challenging task to fulfill, but leads to higher energy densities inside the cell. Water-based processing even adds an extra level of complexity to the procedure. The focus of this work is to implement a multi-layered coating in an industrially relevant process, to overcome issues in electrode integrity and to enable high electrochemical performance. LiNi0.8Mn0.1Co0.1O2 (NMC811) was used as the active material to fabricate single- and multi-layered cathodes with areal capacities of 8.6 mA h cm−2. A detailed description of the manufacturing process is given to establish thick defect-free aqueous electrodes. Good inter-layer cohesion and adhesion to the current collector foil are achieved by multi-layering, as confirmed by optical analysis and peel testing. Furthermore, full cells were assembled and rate capability tests were performed. These tests show that by multi-layering, an increase in specific discharge capacity (e.g., 20.7% increase for C/10) can be established for all tested C-rates.

Impact of Electrode Architecture on Electrochemical Performance of Aqueous Processed, High‐Loaded Lithium‐Ion Battery Cathodes

“…The cause of the more significant delamination of the higherloading AF cathodes might be reduced adhesion of the cathode composite to the aluminum foil current collector due to increased crack formation during drying and/or cycling of the electrodes. [6,7,9,48,49] The lithium metal CE could also contrib-ute to the observed polarizations, as described above. However, it is very unlikely to be the sole origin of the polarization for the AF cathodes.…”

“…[5][6][7] The state-ofthe-art cathode architecture uses an aluminum foil as current collector, upon which the cathode composite gets coated. [7][8][9][10] However, an increase in cathode thickness, in this architecture, is reported to be problematic. The mechanical integrity during drying and cycling, as well as the poor rate performance limit the performance and the lifetime.…”

Experimental Investigation of the Temperature, Pressure, and Binder System Influence on Vacuum Postdrying Processes and Moisture Management of Li‐Ion Battery Electrodes

“…Both binder systems are applicable to anode and cathode, although aqueous processing for cathodes is challenging and the subject of current studies. [ 21–23 ]…”

“…Both binder systems are applicable to anode and cathode, although aqueous processing for cathodes is challenging and the subject of current studies. [21][22][23] Drying experiments at various pressure settings and temperatures elucidate the significance of individual sorption mechanisms of the two electrodes. In addition, mass transport mechanisms that can occur due to system parameters (pressure and temperature) are discussed.…”

Preplanting Nanosilica into Binderless Battery Electrodes for High-Performance Li-Ion Batteries

“…In this regard, regulation of the binder distribution is a prerequisite for improving electrode homogeneity and mechanical integrity of the electrode film. In addition to new binder exploration, advanced electrode architecture that allows mechanical stability and binder uniformity for energy density enhancement has been proposed using different manufacturing methods, such as ice-templating − and multilayer coating methods. ,− Ice-templating-based electrode fabrication with Xanthan and Konjac gum binders allows the formation of vertically aligned microchannels and strong adhesion networks, facilitating Li + transport without electrical connection loss . However, the ice-templated cathode is extremely thick, making it unsuitable for the construction of a compact Li-ion cell because the use of such a cathode compromises the volumetric energy density.…”