Functionalized Single-Ion Charge-Transfer Complexes as Solid-Sate Electrolytes for Lithium Batteries

When and Where

Nov 28, 2023
9:30am - 9:45am

Hynes, Level 3, Room 304

Presenter

Romain Kunert

Noëline Tessier

Laurent Bernard

Lionel Picard

Co-Author(s)

Romain Kunert¹,Noëline Tessier¹,Laurent Bernard¹,Lionel Picard¹

CEA Grenoble¹

Abstract

Romain Kunert¹,Noëline Tessier¹,Laurent Bernard¹,Lionel Picard¹

CEA Grenoble¹

The global climate context has made us reconsider the way to generate and store energy in a more responsible way. The use of alternative renewable energy sources is tightly correlated to the development of electrochemical storage systems. A great example of this idea is with the transition away from vehicles using thermic combustion. While other technologies are slowly maturing, like hydrogen fuel cells, the golden standard in the industry remains lithium-ion batteries.[1] The rising demand for the mass production of portable electronic devices and electric vehicles now leads to new expectations.[2] To fulfill them, research is now focusing on the development of All-Solid-Sate Batteries. The replacement of the conventional liquid electrolytes by solid-state materials is expected to improve safety[3] while ensuring higher energy density with the use of lithium metal as negative electrode.[4] Polymer-based electrolytes have gathered great attention since the first report of lithium ion conductivity in poly(ethylene oxide) in the 1970s.[5] Despite different upsides, these types of materials still show some limitations, especially considering ion conductivity at ambient temperatures. More recently, organic charge-transfer complexes (CTCs) have shown promising super-ionic conductivity in the solid-state at room temperature by associating a donor-acceptor organic couple with a lithium salt.[6] This specific chemical structure holds great potential to tune their electrochemical properties by changing the different partners (acceptor, donor and Li salt) and their molar ratios in the CTC. In this work, we proposed to functionalize charge-transfer complexes to develop single-ion materials, expected to enhance mechanical and electrochemical properties for solid-state batteries.[7] We studied the covalent graphing of polyphenylene polymers with different anions derived from lithium salts conventionally used to develop solid-state electrolytes. We also used these types of single-ion polymers to develop charge-transfer complexes and analyzed their electrochemical properties. The ionic conductivity and lithium transport number of our functionalized CTC electrolytes was compared to the state-of the art CTC conducting materials. We finally offer to rationalize plausible conduction mechanisms in our materials and in the conventional CTC systems that is still in debate today. References [1] B. Owens, Nature, 2015, 526, S89. [2] E. Fan et al., Chem. Rev., 2020, 120, 7020-7063. [3] L. Yue et al., Energy Storage Mater, 2016, 5, 139-165. [4] S. Xia et al., Chem, 2019, 5, 753-785. [5] Z. Xue et al., J. Mater. Chem. A, 2015, 3, 19218-19253. [6] K. Hatakeyama-Sato et al., npj Comput. Mater. 2022, 8, 170. [7] J. Gao et al., Chem. Sci., 2021, 12, 13248-13272.