Aminotriazole-based solid polymer electrolytes for next-gen multivalent batteries: An integrated performance analysis and environmental life cycle perspective

Multivalent-ion batteries offer a sustainable, high-capacity alternative to lithium-ion systems, but their development is limited by the lack of electrolytes enabling efficient ion transport and stable interfaces. This study addresses these challenges by introducing three novel polyamine-type solid electrolytes (SPE) based on 4-amino-1,2,4-triazole units for Ca-ion and Zn-ion batteries. Synthesized under mild conditions (<70 °C) with excellent yields (98–99%), these materials were doped with Ca(TFSI)₂ or Zn(TFSI)₂ and integrated with a PTFE matrix to provide structural integrity and facilitate the formation of flexible, free-standing membranes, while also reducing interface impedance. The electrolytes exhibited high thermal stability (>250 °C) and promising ionic conductivities, with zinc-based systems (up to 0.12 mS·cm⁻¹) outperforming calcium analogues (1.4 × 10⁻³ mS·cm⁻¹). To ensure these materials align with sustainability goals, the electrochemical characterization was complemented by a cradle-to-gate life cycle assessment. The analysis combined primary experimental data with background data from Ecoinvent v3.5. Global Warming Potential ranged from 4.9 × 10⁻² to 8.1 × 10⁻² kg CO₂-eq, with hydrazine use and electricity accounting for over 80% of total impacts. Electrolytes derived from alternative nitrile routes showed significantly lower carbon footprints than the succinonitrile-based counterpart, which, in turn, exhibited the highest ionic conductivity, highlighting a trade-off between environmental performance and electrochemical functionality. Beyond climate change, the succinonitrile-based formulation also showed the highest impacts across toxicity- and resource-related categories. Monte Carlo–based uncertainty analysis confirmed the robustness of these comparative results. Overall, this work introduces a new class of triazole-based SPEs while delivering early environmental insights to inform sustainable materials development in next-generation battery technology.