Advancements in Thin Solid-State Electrolytes for High-Energy Lithium Metal Batteries
Authors: Yoo Seojeong , Choi Sung Ryul , Park Jun-Young 
Published: December 2024

ABSTRACT

In the next generation of lithium-ion batteries (LIBs) utilizing lithium metal as the anode material, a theoretical capacity of 3860 mAh·g-1 can be expected [1]. However, several challenges such as safety issues due to lithium dendrite diffusion during charge-discharge cycling still remain unresolved [2]. The penetration of lithium dendrites remains a concern in traditional solution-based LIBs [3]. As an alternative approach to address the challenges of LIBs, solid-state electrolytes (SSEs) with high ionic conductivity and lithium metal stability have garnered attention [4]. The SSE category includes polymer electrolytes, inorganic sulfide electrolytes, and inorganic oxide electrolytes [5]. Among SSEs, garnet-type Li7La3Zr2O7 (LLZO), is a promising candidate due to its high ionic conductivity within the range of 10-
4 to 10-
3 S∙cm-
1 as well as its thermodynamics reduction stability against Li metal [6, 7].
The introduction of SSB oxide electrolytes would improve packing density and could potentially lead to batteries with negligible self-discharge and longer lifespan of over 104 cycles [8]. During cell operation, solid electrolytes should be mechanically robust and as thin as possible to maximize the valuable volume remaining for the electrodes in SSB cell designs [9]. To compete with the approximately 20μm-thick polymer separators in traditional LIBs, ceramic manufacturing strategies for SSB electrolytes are necessary [10]. Recent estimations suggest that assuming a 25μm-thick solid electrolyte, a lithium metal SSB pouch cell could offer an energy density of 350Wh/kg [11]. In our study, we achieved ultra-thin electrolytes via tape-casting technique into Li-metal battery system. Li symmetric cells based on the ultra-thin electrolyte show exceptional low bulk resistance, attributed to extremely thin electrolyte. Moreover, symmetrical Li cell maintains steady Li plating/stripping cycles for long duration.

Keywords: Lithium-ion batteries, LLZTO, thick solid electrolyte

References

[1] J. M. Tarascon, M. Armand, Nat., 414, (2001) 359-367.
[2] J. Qian, W. A. Henderson, W. Xu, P. Bhattacharya, M. Engelhard, O. Borodin, J. G. Zhang, Nat Commun., 6, (2015) 6362.
[3] Y. Guo, H. Li, T. Zhai, Adv. Mater., 29, (2017) 29.
[4] J. Janek, W. G. Zeier, Nat. Energy., 1, (2016) 16141.
[5] L. J. Miara, S. P. Ong, Y. Mo, W. D. Richards, Y. Park, J. M. Lee, H. S. Lee, G. Ceder, Chem. Mater., 25, (2013) 3048-3055.
[6] L. J. Miara, S. P. Ong, Y. Mo, W. D. Richards, Y. Park, J. M. Lee, H. S. Lee, G. Ceder, Chem. Mater., 25, (2013) 3048-3055.
[7] Y. Zhu, X. He, Y. Mo, ACS Appl. Mater. Interfaces, 7, (2015) 23685-23693.
[8] T. Mageto, S. D. Bhoyate, F. M. de Souza, K. Mensah-Darkwa, A. Kumar, R. K. Gupta, J. Energy Storage, 55, (2022) 105688.
[9] M. Balaish, J. C. Gonzalez-Rosillo, K. J. Kim, Y. Zhu, Z. D. Hood, J. L. M. Rupp, Nat. Energy, 6, (2021), 227–239.
[10] L. Li, Y. Dian, Polymers, 15, (2023) 3690.
[11] X. Wu, K. Pan, M. Jia, Y. Ren, H. He, L. Zhang, S. J. Zhang, GEE, 4, (2019) 360-374.