Chemical compatibility of common additive manufacturing polymers for electrochemical energy storage devices

Purpose – Additive manufacturing is increasingly used for rapid prototyping of lab-scale electrochemical energy storage devices to quickly and cost-effectively screen novel materials and designs. While organic electrolytes offer higher working voltages than aqueous ones, the compatibility of organic solvents with commonly used additive manufacturing materials has been significantly understudied. The purpose of this study is to systematically evaluate the chemical compatibility of common additive manufacturing polymers with organic solvents relevant to electrochemical energy storage applications. Design/methodology/approach – A two-stage framework was used to evaluate 40 polymer-solvent combinations for compatibility. First, swelling tests were conducted by soaking printed polymer samples in solvents for seven days, measuring weight and dimensions before and after exposure. Combinations with minimal swelling were then mechanically tested using tensile tests, comparing untreated samples to those soaked for seven days to assess changes in strength and elastic modulus. Findings – The study found that some polymer-solvent combinations exhibit minimal swelling (<5%) yet undergo significant changes in mechanical properties. This suggests that traditional compatibility assessments based solely on weight and dimensional changes may be inadequate. Photopolymer resins used in stereolithography (SLA) generally outperformed thermoplastics used in fused deposition modeling (FDM). Among the tested materials, Polypropylene (FDM) and Formlabs’ Rigid 10 K (SLA) showed the most promise for applications involving long-term exposure to organic solvents. Additionally, swelling behavior in thermoplastics aligned with predictions from Hansen solubility parameters (HSP), indicating HSP analysis could be a useful prescreening tool. Originality/value – This work introduces a comprehensive framework for evaluating polymer-solvent compatibility beyond conventional swelling metrics, offering valuable insights for the design of additive-manufactured components in electrochemical systems. The findings support the use of HSP analysis for material selection and highlight promising candidates for solvent-resistant applications.