Gigahertz laser ablation of lithium nickel manganese cobalt oxide for lithium-ion batteries

Extensive technological progress is essential to meet the ambitious future requirements of energy storage devices. This is due to the necessity of achieving high energy and power density operations, accompanied by high safety standards and extended lifespans, while maintaining low production and material costs. Lithium-Ion Batteries (LIBs) are expected to continue to be the most preferred energy storage technology for the next decade. Significant importance is placed on the research of high energy active materials for optimizing this technology. However, besides material optimization, there is substantial potential for optimization by introducing electrodes with high mass loading, advanced electrode architecture, and their transfer to mass production and high technology readiness level. Achieving appropriate trade-offs between high energy and power density, process reliability, and economic considerations poses a challenge for current LIBs technology. For this purpose, the laser-assisted generation of three-dimensional (3D) electrode architectures is studied and evaluated with respect to its impact on battery performances and a possible transfer to battery production. Advanced electrode design incorporates micro-and sub-micron structures that can be designed in various ways. Significant improvements in battery lifespan and high-power operation capabilities can be achieved compared to traditional two-dimensional (2D) electrodes. Ablation using high power ultrafast laser has proven to be a precise method for introducing such structures. The production of 3D electrodes with laser support requires coordination with other established manufacturing steps in the battery production process. In particular, the calendering of electrodes holds great importance as it has a significant impact on the microstructural properties of the electrode material, including porosity, material density, and layer adhesion. The present study investigated the impact of laser-induced hierarchical structuring using GHz bursts, comprising micro-/nano-porosities and microtopography, on electrodes with an areal capacity of approx. 4.2 mAh/cm² and different porosity levels. In this regard, electrodes comprising LiNi_0.8Mn_0.2Co_0.2O₂ (NMC 811) were prepared, calendered to calculated porosities between 10% and 40% and subjected to materialographic characterization techniques.