08 Nov Single-ion Monomers and Polymers: Towards high conductive and safer lithium battery electrolytes

Solid-state batteries are attracting significant interest for their potential to reshape the energy storage landscape. Traditional batteries, which rely on liquid electrolytes offer cost and performance advantages but face significant safety concerns, especially with Li-metal anodes and high-potential cathodes.  

Solid-State Batteries : Toward Solid Electrolytes

Solid-state batteries use solid electrolytes that eliminate the use of flammable components. This innovation not only enhances safety by reducing risks of leaks and fires, but are also attracting major interest due to their small volume change during the charging/discharging process and ease of manufacturing. Solid state electrolytes can whether be ceramic or polymer-based. Ceramics excel in conductivity and thermal/electrochemical stability whereas Polymers are cost-effective, flexible, and easier to shape, with reduced sensitivity to oxygen and water compared to ceramics. 

Based on the literature, typical composition of polymer electrolyte formulations for solid-state batteries (SSB) is 60-80% of PEO, 10-30% TFSI salts, and 5-10% of additives. The development of these electrolytes marked a significant first step for all-solid-state batteries. However, this technology now struggles to keep up with the increasing demands of today’s applications. In these binary-ions conductor systems, power delivery is constrained by the concentration gradient of the lithium salt, resulting in a low lithium transference number. Indeed, in such systems, both cations and anions are mobile within the polymer electrolyte phase. In PEO matrices, Li+ cations move much more slowly than anions, which eventually leads to polarization gradients that ultimately reduce electrolyte performance.

Solid-state Batteries : Single-Ion Polymers and Single-Ion Conducting Polymers

Solid-state Batteries : SIM – Single-Ion Monomers 

As part of these activities, SP has been marketing two ‘Single Ion Monomers’ (SIM) since 2017: a methacrylic monomer named MTFSILi (SP-49-023) and a styrenic monomer named STFSILi (SP-59-011). These monomers support companies and research centers in developing new technologies for Single-ion Polymers and Single-Ion Polymer Electrolytes. The availability of these two monomers has enabled many researchers worldwide to develop various types of polymer electrolytes by using them in polymerization or copolymerization reactions with different co-monomers. From 2017 to 2023, the number of scientific articles, publications, and patents based on the use of these two monomers has seen significant growth, clearly demonstrating their relevance in this field. 

Solid-state Batteries : NEW Single-Ion Monomers 

In 2024, we are proud to announce the release and commercialization of two new monomers of interest for this application field. In response to the need for cost reduction and to address regulations surrounding fluorinated compounds, especially PFAS, SPECIFIC POLYMERS scientists have developed two new ‘Single Ion Monomers’ (SIM): SDICYLi (SP-59-021) and SCYLi (SP-59-031). We are currently able to produce these two monomers at the laboratory scale (hundred of grams per batch) and, at this stage of our developments, we have not identified any obstacles to scaling up their production. Once again, we are confident that the commercialization of these new monomers will enable significant advancements of the scientific community in this strategic field. 

At the same time, we will continue our R&D efforts in this field. Our goal and mission remain to fill the gap between academic interest and industrial reality and push the commercialization of Single Ion Monomers, Polymers and Single-Ion Conducting Polymer at the industrial level. Achieving this goal involves numerous challenges, such as addressing process safety, regulations, supply chain issues, performance reproducibility, and more. In recent years, we have made significant progress on these fronts and have been able to increase our production capacity. We are committed to continuing this effort because we are convinced that Single-Ion Polymer (SIP) and Single-Ion Conducting Polymer (SICP) technologies will be at the heart of the energy sector’s transformation by 2030. 

Feel free to contact us if you see any potential for collaboration with our teams in this field. Our expertise in organic and polymer chemistry, combined with our experience in battery electrolytes and industrial approach, enables us to provide strong scientific support. We would be very happy to discuss your projects and explore how we can assist you.