Wednesday, 16 October 2019: 14:20
Room 218 (The Hilton Atlanta)
Lithium metal based all-solid-state batteries (ASSBs) can achieve high energy densities due to high theoretical capacity of lithium and low redox potential (3860 mAh/g, 3.04 V)1-2. Solid electrolyte materials are being sought to replace liquid electrolytes to enable the lithium metal chemistry. Solid electrolytes are mainly classified into two material categories (1) organic and (2) inorganic3. Organic materials are mechanically robust and easier to process but they possess poor ion transport properties. Inorganic materials possess high ionic conductivity but have poor manufacturability. Gravimetric calculations suggest that electrolytes with ≤ 60 μm thickness need to be manufactured to achieve competitive energy densities4. Additionally, the processing platform should ideally merge with existing battery manufacturing infrastructure to enable the transition to ASSBs.
Hybrid electrolytes combine an inorganic conductor with a polymer electrolyte which improves the mechanical properties and inhibits dendrite growth in metal batteries (i.e. short circuiting). This work demonstrates the use of slot-die coaters to manufacture hybrid electrolytes with functional gradation. A custom-made bench-top slot-die coater is used to investigate the impact of ink composition. Initial results have shown that the system is sensitive to processing variability, with nano-scale interactions in the ink phase impacting the macroscopic ink properties and the coating structure5-6. This work focuses on demonstrating manufacturing capabilities for hybrid electrolytes with local control using slot-die coaters. Slot-die coaters are extensively used in industrial scale roll-to-roll manufacturing7 making the process technically viable.
References:
1. Dixit MB, Regala M, Shen F, Xiao X, Hatzell KB. Tortuosity Effects in Garnet Type Li7La3Zr2O12 Solid Electrolytes. ACS Appl Mater Interfaces 2018;11:2022–30.
2. Shen F, Dixit M, Xiao X, Hatzell K. The Effect of Pore Connectivity on Li Dendrite Propagation Within LLZO Electrolytes Observed with Synchrotron X-ray Tomography. ACS Energy Lett 2018;3:1056–61.
3. Fan L, Wei S, Li S, Li Q, Lu Y. Recent Progress of the Solid-State Electrolytes for High-Energy Metal-Based Batteries. Adv Energy Mater 2018;1702657:1–31.
4. McCloskey BD. Attainable Gravimetric and Volumetric Energy Density of Li-S and Li Ion Battery Cells with Solid Separator-Protected Li
Metal Anodes. J Phys Chem Lett 2015;6:4581–8.
5. Hatzell KB, Dixit MB, Berlinger SA, Weber AZ. Understanding Inks for Porous-Electrode Formation. J Mater Chem A 2017;5:20527–33.
6. Dixit M, Harkey B, Shen F, Hatzell KB. Catalyst layer ink interactions that affect coatability. J Electrochem Soc 2018;165:F1–8. doi:10.1149/2.0191805jes.
7. Department of Energy. Roll to Roll Processing Technology Assessment. 2015.