(399f) Enhancing Electrode Interfaces through in Situ Polymerization for Wide Temperature Li-Ion Batteries

Lithium-ion batteries (LiBs) are the driving force behind today's mobile revolution, powering smartphones to electric vehicles [1]. With unparalleled rechargeability and high energy density, they offer wireless freedom and on-the-go charging, enabling sleeker devices and longer trips. Wide temperature range batteries are designed for numerous applications to work efficiently and safely[2]. A safe, lightweight, high-power alternative is solid-state lithium-ion batteries[3].Organic polymeric gels and inorganic solid electrolyte can be used to improve electrochemical performance by effectively blocking dendrite growth. These materials also provide enhanced safety without leaking or spilling liquid. Inorganic solid-state electrolytes[4] have been the subject of much research, but their processing can be complicated and costly due to the need for high-temperature synthesis and additional pressure loads. The main bottleneck for solid-state batteries (SSB) in large-scale applications is the poor conductivity of the Li⁺-ions in the bulk of the electrode/electrolyte interface and electrolyte[5]. Solid-state electrolytes can exhibit poor performance at long cycle life and high current densities due to large interfacial voltage polarizations. These polarizations are caused by kinetic limitations of the Li⁺ ions and sluggish diffusivity at the electrode/electrolyte interfaces. To improve the performance of solid-state electrolytes, it is necessary to address these issues. For applications with extreme and unpredictable temperature conditions beyond the range of standard batteries, special batteries are required. Extensive efforts have been made to address electrode/electrolyte interface issues in solid-state electrolytes[4-5]. It has been shown that the increasing temperature eventually increases Li⁺-ions diffusivity and decreases interfacial resistance. However, it is crucial to note that elevated operating temperatures lead to aging and potentially initiate thermal runaway of LiBs.

This work presents quasi-solid-state electrolytes (QSSE) that are designed for wide-temperature lithium metal batteries, operable within the temperature range of -25°C to 50°C in a scalable approach following in-situ polymerization. Our QSSE electrolytes by customizing properties of the liquid electrolyte entrapped within the polymer, including melting point, viscosity, flash point, and oxidation resistance enable to be cycled at high C-rates up to 3C, which aids in rapid battery charging. The resulting electrolyte achieves an exceptional discharge capacity of 161.4 mAh/g at 0.1 C with 10.0 mg/cm² LFP cathodes. Furthermore, the study demonstrates impressive performance of the cell, as it retains 90 mAh/g after 70 cycles without any degradation at -25°C. Additionally, the cell maintains 80% of its initial capacity (152 mAh/g) after 150 cycles at 1 C at 50°C.

References

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[2] L. Lu, X. Han, J. Li, J. Hua, M. Ouyang, A review on the key issues for lithium-ion battery management in electric vehicles, J Power Sources 226 (2013) 272–288. https://doi.org/10.1016/J.JPOWSOUR.2012.10.060.

[3] X. Yu, R. Chen, L. Gan, H. Li, L. Chen, Battery Safety: From Lithium-Ion to Solid-State Batteries, Engineering 21 (2023) 9–14. https://doi.org/10.1016/J.ENG.2022.06.022.

[4] S. Zhang, Z. Li, Y. Guo, L. Cai, P. Manikandan, K. Zhao, Y. Li, V.G. Pol, Room-temperature, high-voltage solid-state lithium battery with composite solid polymer electrolyte with in-situ thermal safety study, Chemical Engineering Journal 400 (2020) 125996. https://doi.org/10.1016/J.CEJ.2020.125996.

[5] S. Zhang, Z. Li, L. Cai, Y. Li, V.G. Pol, Enabling safer, ultralong lifespan all-solid-state Li-organic batteries, Chemical Engineering Journal 416 (2021) 129171. https://doi.org/10.1016/J.CEJ.2021.129171.