Two-layer cathode architecture for high-energy density and high-power density solid state batteries

Polizos, Georgios; Kalnaus, Sergiy; Chen, Xi Chelsea; Dixit, Marm; Balasubramanian, Mahalingam; Sharma, Jaswinder; Tao, Runming; Li, Jianlin

doi:10.1016/j.mtchem.2023.101704

DOE OSTI · 2007737

Two-layer cathode architecture for high-energy density and high-power density solid state batteries

Polizos, Georgios·Kalnaus, Sergiy·Chen, Xi Chelsea·Dixit, Marm·Balasubramanian, Mahalingam·Sharma, Jaswinder·Tao, Runming·Li, Jianlin

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Abstract

Solid state batteries with high-energy density and high-power density require the development of thick and energy dense cathodes. Structured cathode electrodes with a double-layer configuration were enabled using a freeze tape casting technique. A bottom dense layer was utilized to enhance the energy density whereas a top porous layer with vertically aligned walls was utilized to enhance the power density. The porous structure of the power layer was achieved by ice templating this layer on top of the densified energy layer of the cathode. This configuration was found to better utilize the active material of the cathodes and was optimized using numerical simulation and computer modeling. Cells with Li metal anode and LiNi 0.6 Mn 0.2 Co 0.2 O 2 (NMC622) at approximately 5 and 20 mg/cm 2 were cycled at 70 °C at different C-rates. Poly(ethylene oxide) (PEO) with lithium bis-trifluoromethanesulfonimide (LiTFSI) was used for the catholyte and the solid-state electrolyte. The structured cathodes exhibited more than double capacity values as well as better Coulombic efficiency compared to non-structured (single-layer) thick cathodes. In conclusion, synchrotron X-ray tomography and scanning electron microscopy were used to characterize the microstructure of the cathodes.

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25 ENERGY STORAGE Freeze tape cast cathode Solid state batteries Structured cathode

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Polizos, Georgios, Kalnaus, Sergiy, Chen, Xi Chelsea, Dixit, Marm, Balasubramanian, Mahalingam, Sharma, Jaswinder, Tao, Runming, Li, Jianlin. 2023-08-31. Two-layer cathode architecture for high-energy density and high-power density solid state batteries. https://doi.org/10.1016/j.mtchem.2023.101704

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