Some suppliers of battery binders 64 to commercial adoption, however, primarily in terms of batch-to-batch variability and purity. Their molecular weight and percentage of impurities such as sodium and calcium ions fluctuate, which is unacceptable for gigafactories’ demand for absolute consistency, while the necessary purification to batterygrade standards is costly, so far, and unscaled. Also, these hygroscopic polymers complicate slurry preparation and drying, possess limited thermal stability compared to synthetics such as PVDF, and are electronically and ionically insulating. Development is in the advanced r&d stage, focusing on chemical modification, crosslinking and blending with synthetic binders (SBR/CMC for example) to optimise performance and processability. Their most likely path to market is as performance-enhancing additives in hybrid systems or in niche, high-silicon applications where their adhesive superiority justifies the supply chain complexity. Ultimately, their success depends less on electrochemical promise and more on establishing a reliable, highvolume supply chain that can deliver the consistent purity required by automotivegrade battery manufacturing. Conducting ions and electrons In cathodes, ionic conductivity is as critical as electronic conductivity, so binders that facilitate both represent the ideal, but this is difficult to achieve. One candidate material is lithiated Nafion. Better known as the membrane material in proton-exchange membrane (PEM) fuel cells, its use in battery cell cathodes involves lithiation to enable it to conduct Li+ ions, although its electronic conductivity is low. The second set of candidates in this category consists of designer polymers with built-in ionic functional groups such as lithiated sulfonate (-SO₃Li) or carboxylate (-COOLi) groups tethered to a stable backbone, the idea being to create pathways for Li⁺ motion to move through the binder matrix. Such designer ionic binders tackle a fundamental transport limitation, but they introduce a new set of electrochemical, mechanical and processing complexities. The core challenge is that ionic conduction in solids is inherently linked to soft, dynamic materials, while strong binders are inherently rigid and static. Breaking this inverse relationship is a fundamental problem in materials science. For now, the pragmatic approach is to pursue ultra-efficient traditional binders with optimised conductive additives. Using a highly stable, minimally insulating aqueous binder (such as LA133) in combination with optimised, lower-loading conductive additives (such as single-wall CNTs or specialised carbon blends) is a promising development path. The goal here is to lean into the binder’s core function as a stable glue, while integrating a conductive network so efficient that its weight penalty is kept to a minimum. Solid-state options As solid-state battery (SSB) technology advances, polymeric binders are expected to play an increasingly critical role. They will evolve into functional components of composite electrolytes, requiring ionic conductivity, elasticity and stability at solid–solid interfaces. Materials such as high molecular weight polyisobutylene (HM-PIB) are well suited to meeting the evolving demands at the solid–solid interface – there’s no liquid electrolyte in SSBs January/February 2026 | E-Mobility Engineering Arkema www.arkema.com Ashland www.ashland.com BASF www.basf.com Daikin Industries www.daikinchemicals.com ENEOS Corporation www.eneos-materials.com Kureha Corporation www.kureha.co.jp LG Chem www.lgchem.com Resonac www.resonac.com Sumitomo Seika www.sumitomoseika.co.jp Synthomer www.synthomer.com Syensquo www.syensquo.com Targray www.targray.com Trinseo www.trinseo.com Zeon Corporation www.zeon.co.jp SCC55 features BASF’s Licity 2698-X-F binder for silicon-rich anodes, enhancing battery performance by combining high energy density with greater durability than conventional materials (Image: Group14)
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