Electrochemical Performance of Thick-Film Li(Ni0.6Mn0.2Co0.2)O2 Cathode with Hierarchic Structures and Laser Ablation

Abstract

The electrochemical performance of lithium-ion batteries is directly influenced by type of active material as well as its morphology. In order to evaluate the impact of particle morphology in thick-film electrodes, Li(Ni0.6Mn0.2Co0.2)O2 (NMC 622) cathodes with bilayer structure consisting of two different particle sizes were manufactured and electrochemically characterized in coin cells design. The hierarchical thick-film electrodes were generated by multiple casting using NMC 622 (TA) with small particle size of 6.7 µm and NMC 622 (BA) with large particle size of 12.8 µm. Besides, reference electrodes with one type of active material as well as with two type of materials established during mixing process (BT) were manufactured. The total film thickness of all hierarchical composite electrodes were kept constant at 150 µm, while the thicknesses of TA and BA were set at 1:2, 1:1, and 2:1. Meanwhile, three kinds of thin-film cathodes with 70 µm were applied to represent the state-of-the-art approach. Subsequently, ultrafast laser ablation was applied to generate groove structures inside the electrodes. The results demonstrate that cells with thin-film or thick-film cathode only containing TA, cells with bilayer electrode containing TBA 1:2, and cells with laser-structured electrodes show higher capacity at C/2 to 5C, respectively.

Laser patterning and electrochemical characterization of thick-film cathodes for lithium-ion batteries

“…Our previous works displayed that the cells with laser patterned NMC electrodes exhibit high capacity retention after long-term cycling and show higher capacity at fast charge and discharge rates over C/2 in comparison to reference cells with unstructured electrodes. 8,14,15 , while other researchers observed similar phenomenon using other cathode materials such as LCO with line structures 16 , and LFP with hole structures 17 . Besides, laser patterned graphite-based anodes (with or without silicon) with lines, grids, and holes display high capability at elevated C-rates [18][19][20][21] .…”

Influence of Laser Structuring and Calendering of Graphite Anodes on Electrode Properties and Cell Performance

“…24,25 Since graphite anodes typically show higher diffusion limitations than most cathodes, electrode structuring is especially promising when applied to anodes. 26,27 Nevertheless, performance enhancements were also reported for LIBs containing structured LiMn 2 O 4 (LMO), 28 LiCoO 2 (LCO), 29,30 LiNi x Mn y Co z O 2 (NMC) [31][32][33] and LiFePO 4 (LFP) cathodes. 22,34 Additionally, it could be shown that the time-consuming electrolyte filling process, which largely contributes to the production costs of LIBs, 35 can be significantly accelerated through electrode structuring.…”

“Zero” Porosity High Loading NMC622 Positive Electrodes for Li-Ion Batteries

“…Two redox peaks were observed within the range of 3.50 V to 4.02 V, indicating the presence of oxidation (Ni 2+ → Ni 3+ → Ni 4+ ) during charging and reduction (Ni 4+ → Ni 3+ → Ni 2+ ) during discharging. 17 By employing CV, the peak potentials for the anodic and cathodic sweeps can be identified, which are respectively known as E pa and E .…”